POTASSIUM CYANIDE
(Strongly Suspected)

POTASSIUM CYANIDE
CASRN: 151-50-8
http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~AAAsGay8K:1

Human Health Effects:

Human Toxicity Excerpts:

... IT IS POSSIBLE FOR CYANIDE TO CAUSE BLINDNESS & TO DAMAGE OPTIC NERVES & RETINA. /CYANIDE/
[Grant, W. M. Toxicology of the Eye. 2nd ed. Springfield, Illinois: Charles C. Thomas, 1974. 334]**PEER REVIEWED**

MOST SPECIFIC PATHOLOGICAL FINDING IN ACUTE CASES /OF CYANIDE POISONING/ IS BRIGHT RED COLOR OF VENOUS BLOOD. THIS IS STRIKING, VISIBLE EVIDENCE OF INABILITY OF TISSUE CELLS TO UTILIZE OXYGEN ... VENOUS BLOOD IS ONLY ABOUT 1 VOL % LOWER IN OXYGEN CONTENT THAN ARTERIAL BLOOD ... /CYANIDES/
[Clayton, G.D., F.E. Clayton (eds.) Patty's Industrial Hygiene and Toxicology. Volumes 2A, 2B, 2C, 2D, 2E, 2F: Toxicology. 4th ed. New York, NY: John Wiley & Sons Inc., 1993-1994. 3125]**PEER REVIEWED**

WORKERS IN ELECTROPLATING INDUST HAVE SHOWN DERMATITIS TO BE A PROBLEM. ALSO REPORTED WERE ITCHING, SCARLET RASH, PAPULES ... IRRITATION OF NOSE, LEADING TO OBSTRUCTION, BLEEDING, SLOUGHS AND IN SOME CASES PERFORATION OF SEPTUM. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 575]**PEER REVIEWED**

... ENLARGED THYROID GLANDS /WERE REPORTED/ IN WORKERS EXPOSED TO CYANIDE SALTS IN HEAT TREATMENT OF METALS. IT WAS SUGGESTED THAT ABSORPTION OF CYANIDE DUST & HYDROGEN CYANIDE PRODUCED BY HYDROLYSIS OF CYANIDE SALTS, WAS FOLLOWED BY METABOLISM TO THIOCYANATE, & THAT FAILURE TO ELIMINATE THIS ... CAUSED GOITROGENIC EFFECT. /CYANIDE SALTS/
[American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati, OH:American Conference of Governmental Industrial Hygienists, 1986. 153]**PEER REVIEWED**

SYMPTOMATOLOGY: 1. Massive doses may produce, without warning, sudden loss of consciousness and prompt death from respiratory arrest. With smaller but still lethal doses, the illness may be prolonged for 1 or more hours. 2. Upon ingestion, a bitter, acrid, burning taste is sometimes noted, followed by a feeling of constriction or numbness in the throat. Salivation, nausea and vomiting are not unusual ... 3. Anxiety, confusion, vertigo, giddiness, and often a sensation of stiffness in the lower jaw. 4. Hyperpnea and dyspnea. Respirations become very rapid and then slow and irregular. Inspiration is characteristically short while expiration is greatly prolonged. 5. The odor of bitter almonds may be noted on the breath or vomitus ... 6. In the early phases of poisoning, an increase in vasoconstrictor tone causes a rise in blood pressure and reflex slowing of the heart rate. Thereafter the pulse becomes rapid, weak, and sometimes irregular ... A bright pink coloration of the skin due to high concentrations of oxyhemoglobin in the venous return may be confused with that of carbon monoxide poisoning. /Cyanide/
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-126]**PEER REVIEWED**

SYMPTOMATOLOGY: 7. Unconsciousness, followed promptly by violent convulsions, epileptiform, or tonic, sometimes localized but usually generalized. Opisthotonos and trismus may develop. Involuntary micturition and defecation occur. 8. Paralysis follows the convulsive stage. The skin is covered with sweat. The eyeballs protrude, and the pupils are dilated and unreactive. The mouth is covered with foam, which is sometimes bloodstained. ... The skin color may be brick red. Cyanosis is not prominent in spite of weak and irregular gasping. In the unconscious patient, bradycardia and the absence of cyanosis may be key diagnostic signs. 9. Death from respiratory arrest. As long as the heart beat continues, prompt and vigorous treatment offers some promise of survival. /Cyanide/
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-127]**PEER REVIEWED**

A STUDY WAS UNDERTAKEN TO ASSESS THE HEALTH STATUS OF WORKERS EXPOSED TO CYANIDE FUMES & AEROSOLS IN A FACTORY. CYANIDE LEVELS WERE MEASURED IN THE WORK ENVIRONMENT & IN BLOOD & URINE. SMOKERS HAD HIGHER CONCENTRATIONS THAN NON-SMOKERS. THE HIGHEST LEVELS WERE 0.8 & 0.2 MG/CU M IN BREATHING ZONE & GENERAL WORKROOM ATMOSPHERE, RESPECTIVELY. THE WORKERS COMPLAINED OF TYPICAL CYANIDE POISONING IN SPITE OF THE LOW CONCN. ... /CYANIDES/
[CHANDRA H ET AL; J ANAL TOXICOL 4 (4): 161-65 (1980)]**PEER REVIEWED**

A 60 year old chemist was admitted two hours after voluntary intake of 600 mg potassium cyanide. Upon admission he was in deep coma and bradypneic but non-cyanotic. Arterial blood gas analysis showed severe lactic acidosis; blood cyanide concentration was well above the lethal level. The patient was intubated and artificially ventilated with highly hyperoxic mixtures. Specific treatment included sodium nitrite and sodium thiosulfate. The patient recovered without sequelae despite excessive methemoglobinemia.
[Feihl F et al; Schweiz Med Wochenschr 112 (37): 1280-82 (1982)]**PEER REVIEWED**

An 18 year old man ingested 975 to 1,300 mg of potassium cyanide in a suicide attempt. He was treated and survived the poisoning episode, but then had severe parkinsonian syndrome, characterized primarily by akinesia and rigidity. He died 19 months after the drug overdose. At autopsy, major destructive changes were found in the globus pallidus and putamen, whereas the melanin-containing zone of substantia nigra was intact. This is the first clinicopatholic report of parkinsonism as a result of cyanide poisoning.
[Uitti RJ et al; Neurology 35 (6): 921-25 (1985)]**PEER REVIEWED**

THE TLV FOR ALKALI CYANIDES ... IS BASED ON ADDED IRRITATION CAUSED BY ALKALINITY, SUFFICIENT TO RESULT IN EPISTAXIS (NOSEBLEED) & NASAL ULCERATION. AIR CONCN OF CYANIDE FROM ALKALI CYANIDES PRODUCING THIS EFFECT (NOSEBLEED) DID NOT GREATLY EXCEED 5 PPM. /ALKALI CYANIDES/
[American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values for Substances in Workroom Air. Third Edition, 1971. Cincinnati, Ohio: AmericanConference of Governmental Industrial Hygienists, 1971. (Plus supplements to 1979) 64]**PEER REVIEWED**

Ingestion of potassium cyanide or sodium cyanide causes congestion & corrosion of the gastric mucosa.
[Dreisbach, R.H. Handbook of Poisoning. 12th ed. Norwalk, CT: Appleton and Lange, 1987. 253]**PEER REVIEWED**

... Strong solutions are corrosive to skin & may cause deep ulcers.
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

Cyanides are absorbed from the skin & mucosal surfaces and are ... dangerous when inhaled because toxic amt are ... absorbed through bronchial mucosa & alveoli. Symptoms, which /may/ occur ... are giddiness, headache, palpitation, dyspnea, & unconsciousness. There may be some evidence of local irritation from the salts & nausea & vomiting. ... Central nervous depression. ... Early electrocardiographic changes may include atrial fibrillation, ectopic ventricular beats, and abnormal QRS complex with T wave originating high on the R wave. Sinus bradycardia is a common presenting sign. As cyanide levels in the blood rise, ataxia develops & is followed by coma, convulsions, & death. /Cyanides/
[Haddad, L.M. and Winchester, J.F. Clinical Management of Poisoning and Drug Overdosage. Philadelphia, PA: W.B. Saunders Co., 1983. 745]**PEER REVIEWED**

Signs & symptoms of acute cyanide poisoning reflect cellular hypoxia & are often nonspecific. Onset of symptoms depends on dose, route, & duration of exposure. Inhalation produces ... flushing, headache, tachypnea, & dizziness ... irregular stridulous breathing, coma, seizure, & death ... /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1478]**PEER REVIEWED**

WHEN ABSORBED, /CYANIDE/ ... REACTS READILY WITH ... CYTOCHROME OXIDASE IN MITOCHONDRIA; CELLULAR RESPIRATION IS THUS INHIBITED & CYTOTOXIC HYPOXIA RESULTS. ... RESPIRATION IS /INITIALLY/ STIMULATED ... A TRANSIENT STAGE OF CNS STIMULATION WITH HYPERPNEA AND HEADACHE IS OBSERVED; FINALLY THERE ARE HYPOXIC CONVULSIONS AND DEATH DUE TO RESPIRATORY ARREST. /CYANIDE/
[Gilman, A.G., L.S.Goodman, and A. Gilman. (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 7th ed. New York: Macmillan Publishing Co., Inc., 1985. 1642]**PEER REVIEWED**

... IT IS POSSIBLE FOR CYANIDE TO CAUSE BLINDNESS & TO DAMAGE OPTIC NERVES & RETINA. /CYANIDE/
[Grant, W. M. Toxicology of the Eye. 2nd ed. Springfield, Illinois: Charles C. Thomas, 1974. 334]**PEER REVIEWED**

VOLATILE CYANIDES /SRP: AND ALL AIRBORNE CYANIDE SALTS/ RESEMBLE HYDROCYANIC ACID PHYSIOLOGICALLY, INHIBITING TISSUE OXIDN & CAUSING DEATH THROUGH ASPHYXIA. CYANOGEN IS PROBABLY AS TOXIC AS HYDROCYANIC ACID ... /CYANIDES/
[Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984. 822]**PEER REVIEWED**

CYANIDES SUCH AS ... HYDROGEN CYANIDE, POTASSIUM CYANIDE AND SODIUM CYANIDE ARE ACUTELY POISONOUS, INTERFERING WITH METABOLIC PROCESSES & CAUSING RAPID DEATH. IN SEVERE POISONING, PUPILS ARE CHARACTERISTICALLY WIDELY DILATED.
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 287]**PEER REVIEWED**

... Strong solutions are corrosive to skin ...
[U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.]**PEER REVIEWED**

CYANIDES SUCH AS ... HYDROGEN CYANIDE, POTASSIUM CYANIDE AND SODIUM CYANIDE ARE ACUTELY POISONOUS, INTERFERING WITH METABOLIC PROCESSES & CAUSING RAPID DEATH. IN SEVERE POISONING, PUPILS ARE CHARACTERISTICALLY WIDELY DILATED.
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 287]**PEER REVIEWED**

In minimal lethal doses, cyanide affects primarily the central nervous system. Cyanide initially stimulates the peripheral chemoreceptors, causing increased respirations. It also promotes slowing of the heart by stimulating the carotid body receptors. The electrical activity of the brain may stop while the heart is still beating. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1478]**PEER REVIEWED**

The most common symptoms of a long-term cyanide exposure that has exceeded current standards have been headache, dizziness, nausea or vomiting, and a bitter or almond taste. Mild abnormalities of vitamin B12, folate, and thyroid function have been noted, but symptoms did not correlate with these changes. Other excessive exposures to cyanide have resulted in psychosis and thyroid enlargement without symptoms of thyroid dysfunction. Several clinical syndromes have been associated with chronic cyanide toxicity ... . These diseases may be due to high cyanide levels, impaired cyanide detoxification mechanisms, nutritional deficiencies, or some combination of these factors. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1479]**PEER REVIEWED**

In serious poisonings, the skin is cold, clammy, and diaphoretic. Cyanosis may be a late finding, since poor tissue utilization of oxygen results in elevated venous oxygen levels. Retinal veins and arteries may appear similar in color because of the elevated venous oxygen level. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1479]**PEER REVIEWED**

Depression of the cardiovascular system requires cyanide doses higher than those necessary for depression of the CNS. Initial tachycardia occurs followed by bradycardia.. Dysrhythmias and hypotension often precede peripheral vascular collapse. The ECG may display striking ischemic changes; pulmonary edema may complicate severe intoxications. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1479]**PEER REVIEWED**

The CNS is the most sensitive target organ of cyanide poisoning, with early stimulation followed by CNS depression. Early symptoms include lightheadedness, giddiness, tachypnea, nausea, vomiting, feeling of neck constriction and suffocation, confusion, restlessness, and anxiety. Initial tachypnea results from direct stimulation of carotid body chemoreceptors followed by respiratory depression. Severe cyanide poisonings progress to stupor, coma, opisthotonus, convulsions, fixed dilated pupils, and death. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997.,p. 1478-9]**PEER REVIEWED**

A deadly human poison by ingestion. An experimental poison by ocular, subcutaneous, intravenous, intramuscular, and intraperitoneal routes
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

Medical Surveillance:

Initial medical examination /should include/: a complete history and physical examination ... to detect existing conditions that might place the exposed employee at incr risk & to establish a baseline for future health monitoring. ... Examination of cardiovascular, nervous, & upper resp systems, & thyroid should be stressed. The skin should be exam for evidence of chronic disorders. ... The aforementioned medical exam should be repeated on an annual basis. ... /Cyanides/
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 1]**PEER REVIEWED**

Pre-placement and periodic examinations should include the cardiovascular and central nervous systems, liver and kidney function, blood, history of fainting and dizzy spells. Blood cyanide levels may be useful during acute intoxication. Urinary thiocyanate levels have been used but are nonspecific and are elevated in smokers. /cyanides/
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 508]**PEER REVIEWED**

Arterial Blood Gases: Arterial blood gases may be useful for monitoring of metabolic acidosis that can occur from cyanide poisoning. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 912]**PEER REVIEWED**

EKG Measurement: EKG monitoring may be useful since changes have been found with cyanide exposure. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 912]**PEER REVIEWED**

The assessment of cyanide exposure can be accomplished through measurement of cyanide. Most information found in the literature regarding monitoring for absorption of cyanide preferred the measurement of blood cyanide. ... Blood Reference Ranges: Normal - non-smokers, <0.02 ug/ml; smokers, average 0.041 ug/ml; Exposed - Levels of <0.2 ug/ml have been found to be non-toxic; however, levels of 0.5 - 1.0 ug/ml have been associated with tachycardia and flushing. Toxic - Levels of 1.0 - 2.5 ug/ml have been associated with obtundation; coma and respiratory depression with levels greater than 2.5 ug/ml; death with values greater than 3 ug/ml. Serum or Plasma Reference Ranges: Normal - cyanide: nonsmoker, 0.004 ug/ml; smoker, 0.006 ug/ml; Exposed - not established; Toxic - cyanide; greater than 0.1 ug/ml. Urine Reference Ranges: Normal - not established; Exposed - not established; Toxic - not established. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 911]**PEER REVIEWED**

Respiratory Symptom Questionnaires: Questionnaires have been published by the American Thoracic Society and the British Medical Research Council. These questionnaires have been found to be useful in identification of people with chronic bronchitis, however certain pulmonary function tests such as FEV1 have been found to be better predictors of chronic airflow obstruction. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 913]**PEER REVIEWED**

Chest Radiography: This test is widely used for assessing pulmonary disease. Chest radiographs have been found to be useful for detection of early lung cancer in asymptomatic people, especially for detection of peripheral tumors such as adenocarcinomas. However, even though OSHA mandates this test for exposure to some toxicants such as asbestos, there are conflicting views on its efficacy in detection of pulmonary disease. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 913]**PEER REVIEWED**

Pulmonary Function Tests: The tests that have been found to be practical for population monitoring include: Spirometry and expiratory flow-volume curves; Determination of lung volumes; Diffusing capacity for carbon monoxide; Single-breath nitrogen washout; Inhalation challenge tests; Serial measurements of peak expiratory flow; Exercise testing. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 913]**PEER REVIEWED**

Evaluation of Peripheral Neuropathy: Nerve conduction study; Electromyography; Quantitative sensory testing; Thermography. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 914]**PEER REVIEWED**

Evaluation of Central Nervous System Effects: Evaluation of CNS effects can be performed through neuropsychological assessment, which consists of a clinical interview and administration of standardized personality and neuropsychological tests. The areas that the neuropsychology test batteries focus on include the domains of memory and attention; visuoperceptual, visual scanning, visuospatial, and visual memory; and motor speed and reaction time. There is limited data on which components of the test batteries are best indicators of early CNS effects. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 914]**PEER REVIEWED**

Evaluation of Cranial Neuropathies: Evaluation of cranial nerve damage, as evidenced by symptoms such as loss of balance, visual function, smell, taste, or sensation on the face, can be accomplished through a physical examination focusing on tests such as: Smell Assessment ... Visual Assessment ... Facial and Trigeminal Nerve Assessment ... Vestibular Assessment ... Hearing Assessment. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 914]**PEER REVIEWED**

Populations at Special Risk:

WORKERS WITH CHRONIC DISEASES OF KIDNEYS, RESPIRATORY TRACT, SKIN OR THYROID ARE @ GREATER RISK OF DEVELOPING TOXIC CYANIDE EFFECTS THAN ARE HEALTHY WORKERS. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 576]**PEER REVIEWED**

Probable Routes of Human Exposure:

Poisoning may occur by ingestion, absorption through injured skin or inhalation of hydrogen cyanide, liberated by action of carbon dioxide or other acids.
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 1100]**PEER REVIEWED**

... SYMPTOMS OF CHRONIC DISEASE ... REPORTED IN ELECTROPLATERS & SILVER POLISHERS AFTER SEVERAL YEARS OF EXPOSURE. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 575]**PEER REVIEWED**

AMONG FUMIGATORS ... CYANIDE POISONING IS RECOGNIZED ... /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 575]**PEER REVIEWED**

DERMATITIS ... IN WORKERS CHRONICALLY EXPOSED TO CYANIDE SOLN. ELECTROPLATERS SUFFER FROM SUCH IRRITATION. /CYANIDE SOLN/
[Hamilton, A., and H. L. Hardy. Industrial Toxicology. 3rd ed. Acton, Mass.: Publishing Sciences Group, Inc., 1974. 224]**PEER REVIEWED**

Body Burden:

Cyanide is present in normal healthy human organs at concentrations ranging up to 0.5 mg/kg. /Cyanide/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.48 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Antidote and Emergency Treatment:

Due to the apparent low binding capacity of activated charcoal for potassium cyanide (KCN) in vitro, the use of oral activated charcoal therapy for oral exposure to cyanide compounds is controversial. In our study, rats were given a lethal oral dose of ground granular KCN (35 or 40 mg/kg) in a gelatin capsule followed immediately by either 4 g/kg of superactivated charcoal in a 20% suspension or a similar volume of deionized water. Signs of cyanide toxicosis occurred rapidly, with a mean time to signs of 3.3 and 2.7 min in control animals receiving 35 or 40 mg/kg KCN, respectively. All 26 of the control rats showed signs, and all but one in the 35 mg/kg group died within 19 min. Only 12 of 26 rats treated with superactivated charcoal showed signs of KCN toxicosis and eight of those animals died.
[Lambert RJ et al; Ann Emerg Med 17 (6): 595-8 (1988)]**PEER REVIEWED**

The oxidative disposition of potassium cyanide was studied in mice. Male Swiss-Webster mice were injected sc with 4.6 mg/kg (14)C labeled potassium cyanide. The animals were observed for signs of toxicity. Expired air was collected and assayed for radiolabeled hydrocyanic acid and carbon dioxide for up to 210 min after injection. Mice were pretreated with antidotal agents sodium nitrate, sodium thiosulfate, oxygen, alone or in combination, or oxygen intermediates hydrogen peroxide, 3-amino-1,2,4-triazole, superoxide dismutase, or diethyldithiocarbamic acid, and injected sc with potassium cyanide. Expired air was assayed for radioactive hydrocyanic acid and carbon dioxide as before. Potassium cyanide caused a transient decrease in exploratory behavior 1 to 2 min after injection, which returned to normal within 10 min. This was accompanied by a slight decrease in respiratory rate and dyspnea. These effects were not seen in animals pretreated with the antidotes. Approximately 1 and 2 percent of the potassium cyanide dose was expired as radiolabeled hydrocyanic acid and carbon dioxide, respectively. Pretreatment with the cyanide antidotes significantly reduced expiration of the pulmonary metabolites.
[Johnson JD, Isom GE; Toxicol 37 (3-4): 215-24 (1985)]**PEER REVIEWED**

The use of the combination consisting of 4 g of hydroxoycobalamin and 8 g of sodium thiosulfate as an antidote in cases of cyanide poisoning is reviewed. The antidote, which has been used in France since 1970, has proved to be nontoxic and therefore can be given in cases where the diagnosis of cyanide poisoning is not absolutely certain. On the other hand, the Lilly Cyanide Antidote Kit, which has been approved for use in the USA for the same purpose, has been shown to be toxic and its use requires caution. The antidotal effectiveness of the association of hydroxoycobalamin and sodium thiosulfate has been demonstrated in mice and other animal species poisoned with cyanide. Most animal studies reveal a strong antidotal synergism between the two agents. In France, the efficacy of the antidotal combination has been proved in patients who have ingested as much as 1.5 g of potassium cyanide and have blood cyanide levels on the order of 15 ug/ml. In the USA, the antidotal combination is designated as an orphan drug by the FDA and studies have been started to validate its safety and efficacy before being approved for use in this country. /Cyanide/
[Hall AH, Rumack BH; J Emer Med 5 (2): 115-21 (1987)]**PEER REVIEWED**

A 34 year old, 73 kg man ingested a 1 g potassium cyanide pellet in a suicide attempt. Within one hour, coma, apnea, metabolic acidosis, and seizures developed. Sodium nitrite and sodium thiosulfate were administered. Dramatic improvement in the clinical condition occurred by the completion of antidote infusion. Methemoglobin level was 2% immediately after nitrite administration. Serial whole blood cyanide levels were obtained, documenting a highest measured level of 15.68 ug/ml. Estimations of toxicokinetic parameters including terminal half-life (19 hr), clearance (163 ml/minute), and volume of distribution (0.41 l/kg) were calculated. The nitrite/thiosulfate combination was clinically efficacious in this case and resulted in complete recovery.
[Hall AH et al; J Toxicol Clin Toxicol 25 (1-2): 121-33 (1987)]**PEER REVIEWED**

A coincubation system composed of hepatocytes in primary monolayer culture and erythrocytes suspended in the culture medium was developed and used as a model for investigations of mechanisms of cyanide antidote action at the cellular level. Hepatocyte ATP was used as the cytotoxicity indicator. Treatment of rat hepatocytes in the coincubation system with potassium cyanide (KCN) (1.0 mM) for 10 min at 37 deg C selectively reduced hapatocyte ATP levels to 33 + or - 15% of control (no KCN added) levels. 4-dimethylaminophenol, cobalt(II) chloride, sodium nitrite, sodium thiosulfate, or a combination of the last two antidotes added to the KCN-containing medium significantly reversed ATP depression and the response was concentration dependent. The relative effectiveness, on a molar basis, was estimated to be 4-dimethylaminophenol greater than cobalt(II) chloride much greater than sodium nitrite congruent to sodium thiosulfate. Sodium nitrite and 4-dimethylaminophenol induced methemoglobin formation in the absence of cyanide and cyanomethemoglobin formation in its presence; erythrocytes were required in the medium for effectiveness. Cobalt(II) chloride produced neither cyanomethemoglobin nor thiocyanate in appreciable quantities nor required erythrocytes for antagonism. Sodium thiosulfate converted cyanide to thiocyanate and reversed ATP depression without erythrocytes in the medium. The addition of erythrocytes increased these rates significantly and to a greater extent than albumin.
[Gee SJ et al; Toxicol Appl Pharmacol 88 (1): 24-34 (1987)]**PEER REVIEWED**

/Experimental Therapy:/ The effect of hemodialysis in dogs receiving a constant infusion of cyanide with and without a simultaneous infusion of thiosulfate was studied. The hemodialysis clearance of cyanide in the presence of thiosulfate was 38.3 + or - 5.4 ml/min with an extraction ratio of 0.43 + or - 0.06 (n= 4). hemodialysis was found to increase the lethal dose of cyanide without thiosulfate infusion, and a further increase was noted with the thiosulfate infusion. Thiosulfate promotes mitochondrial metabolism of cyanide to thiocyanate. The end product, thiocyanate, is quickly removed by hemodialysis. The demonstrated effectiveness of hemodialysis in the treatment of acute cyanide intoxication is related not only to the hemodialysis clearance of cyanide, but also to the removal of its metabolic end product, thiocyanate. /Cyanide/
[Wesson DE et al; Am J Nephrol 5 (2): 121-26 (1985)]**PEER REVIEWED**

Basic Treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 l/min. Administer amyl nitrite ampules as per protocol and physician order ... . Monitor for shock and treat if necessary ... . Monitor for pulmonary edema and treat if ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . /Cyanide and related compounds/
[Bronstein, A.C., P.L. Currance; Emergency Care for Hazardous Materials Exposure. 2nd ed. St. Louis, MO. Mosby Lifeline. 1994.,p. 387-8]**PEER REVIEWED**

Advanced Treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious or in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Administer cyanide antidote kit as per protocol and physician order ... . Monitor and treat cardiac arrhythmias if necessary ... . Consider vasopressors to treat hypotension without signs of hypovolemia ... . Consider drug therapy for pulmonary edema ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Cyanide and related compounds/
[Bronstein, A.C., P.L. Currance; Emergency Care for Hazardous Materials Exposure. 2nd ed. St. Louis, MO. Mosby Lifeline. 1994. 388]**PEER REVIEWED**

Although a variety of agents are effective antidotes in the experimental animal (nitrites, dimethylaminophenol, cobalt EDTA, hydroxocobalamin, stroma-free methemoglobin solutions, pyruvate, thiosulfate, sulfur sulfanes, mercaptopyruvate, oxygen) only the three-step Eli-Lilly cyanide kit is approved in the US. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1481]**PEER REVIEWED**

/SRP: For patients treated with nitrites:/ Measurement of methemoglobin may be useful for assessing exposure. However, methemoglobin levels may be artificially low if not analyzed within a few hours after drawing the blood. Methemoglobin levels have been found to correlate with clinical symptoms in most cases. /Cyanide/
[Ryan, R.P., C.E. Terry (eds.). Toxicology Desk Reference 4th ed. Volumes 1-3. Taylor & Francis, washington, D.C. 1997. 912]**PEER REVIEWED**

Animal Toxicity Studies:

Non-Human Toxicity Excerpts:

... DAILY SC INJECTIONS OF POTASSIUM CYANIDE INCR GRADUALLY TO LETHAL LEVELS HAS CAUSED NYSTAGMUS & PERIODS OF BLINDNESS IN MONKEYS, CATS, DOGS, & RATS, WITH HISTOLOGICALLY DEMONSTRABLE DEGENERATION IN OPTIC NERVE, CHIASM, & OPTIC TRACT.
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 287]**PEER REVIEWED**

CYANIDES SUCH AS ... HYDROGEN CYANIDE, POTASSIUM CYANIDE AND SODIUM CYANIDE ARE ACUTELY POISONOUS, INTERFERING WITH METABOLIC PROCESSES & CAUSING RAPID DEATH. IN SEVERE POISONING, PUPILS ARE CHARACTERISTICALLY WIDELY DILATED.
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 287]**PEER REVIEWED**

IN AWAKE RATS, POTASSIUM CYANIDE INJECTED IP, INCR 2,3-DIPHOSPHOGLYCERATE (DPG) BLOOD LEVELS. POTASSIUM-INDUCED INCR OF DPG APPEARS TO CONSTITUTE A RESPONSE TO HYPOXIA.
[LACROIX P ET AL; CR SEANCES SOC BIOL SES FIL 172 (2): 330-36 (1978)]**PEER REVIEWED**

STUDIES TO DETERMINE WHETHER MUTAGENIC SUBSTANCES WOULD MODIFY DNA REPLICATIVE ACTIVITY WERE PERFORMED. 2.6 MG/KG OF POTASSIUM CYANIDE DID NOT CAUSE INHIBITION OF MOUSE TESTICULAR DNA SYNTHESIS.
[FRIEDMAN MA, STAUB J; MUTAT RES 37 (1): 67-76 (1976)]**PEER REVIEWED**

Pigs were allotted to 3 treatment groups comprising a maize control ration (1), cassava peel rations (2) and a cassava peel + dietary potassium cyanide rations (3). Diets 1-3 contained 0, 96, and 400 ppm cyanide, respectively. Feed intake and growth rate were non-significantly (p > 0.05) reduced on cassava peel containing ration. Feed efficiency and protein efficiency ratio on the cassava peel based rations compared favorably with the control. Performance traits (daily weight gain, daily feed intake, feed efficiency) were /had no effect/ (p > 0.05) with dietary cyanide level. Nutrient digestibility was similar in all treatment groups except for ether extract digestibility which was significantly (p > 0.05) higher on rations 2 and 3. Metabolizable energy and N retention per day were not affected by dietary treatments.
[Tewe OO, Persu E; Nutr Rep Int 26 (1): 51-58 (1982)]**PEER REVIEWED**

Cumulative effects of adding 500 ppm potassium cyanide to a cassava root flour-based diet were studied. High dietary level of potassium cyanide did not have any marked effect in gestation and lactation performance of female rats. No carry-over effect of level of cyanide fed during gestation was observed on lactation performance. The high cyanide containing diet significantly reduced feed consumption and daily growth rate of the offspring when fed during postweaning growth. Protein efficiency ratio was reduced by the high cyanide diet during the postweaning growth phase and there was a carry-over effect from gestation. Serum thiocyanate was significantly increased in lactating rats and their offspring during lactation and in the postweaning growth phase of the pups. No apparent carry-over effect was noticed on this parameter. Rhodanese activity in liver and kidney was unaffected by feeding the high cyanide diet during gestation, lactation and/or during postweaning growth.
[Tewe OO, Maner JH; Toxicol Appl Pharmacol 58 (1): 1-7 (1981)]**PEER REVIEWED**

THE ACUTE SYSTEMIC TOXICITY OF HYDROGEN CYANIDE, SODIUM CYANIDE AND POTASSIUM CYANIDE BY INSTILLATION INTO THE INFERIOR CONJUNCTIVAL SAC WAS INVESTIGATED. USING RABBITS, THE LD50 VALUE FOR POTASSIUM CYANIDE WAS 0.121 MMOL/KG. SIGNS OF TOXICITY APPEARED RAPIDLY AND DEATH OCCURRED WITHIN 3-12 MINUTES OF THE EYE BEING CONTAMINATED. THUS, FOLLOWING OCULAR INSTILLATION, CYANIDES MAY BE ABSORBED ACROSS THE CONJUNCTIVAL BLOOD VESSELS IN AMOUNTS SUFFICIENT TO PRODUCE SYSTEMIC TOXICITY.
[BALLANTYNE B; J TOXICOL, CUTANEOUS OCUL TOXICOL 2 (2-3): 119-29 (1983)]**PEER REVIEWED**

IN EXPTL ANIMALS, DEMONSTRATION OF EFFECTS OF CYANIDE POISONING ON RETINA & OPTIC NERVE HAS BEEN SUCCESSFUL PRINCIPALLY WITH ACUTE SEVERE, NEAR-LETHAL, OR LETHAL POISONINGS. /CYANIDE/
[Grant, W. M. Toxicology of the Eye. 2nd ed. Springfield, Illinois: Charles C. Thomas, 1974. 334]**PEER REVIEWED**

IN RABBITS, AFTER SUBLETHAL DOSES OF CYANIDE, CHANGES IN ELECTRORETINOGRAM HAVE BEEN OBSERVED. /CYANIDES/
[Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986. 287]**PEER REVIEWED**

Chronic implantation of surface coils on the skull was developed to record (31)P NMR spectra of the brain in unanesthetized rats. Ip sublethal doses induced strong and reversible changes in high-energy phosphate compounds in the brain, similar in part to those induced by ischemia. These effects were dose-dependent as far as phosphocreatine, inorganic orthophosphates, and pH were concerned; ATP does not seem to be altered by potassium cyanide doses of 3-5 mg/kg, but decreased at 6 mg/kg. The fraction of Mg(2+)-complexed ATP (approximately 90%) was not affected by potassium cyanide intoxication.
[Decorps M et al; FEBS Lett 168 (1): 1-6 (1984)]**PEER REVIEWED**

Hepatic hexose transport was characterized in rats using 3-O-methyl-D-glucose, which is not metabolized by the liver. The effects of N2-induced anoxia and of potassium cyanide were investigated. In the fasted state, anoxia caused the transport characteristics Vmax and Km to decrease nearly 2 fold whereas potassium cyanide had the opposite effect as the Vmax and Km were increased by 3 and 2 fold, respectively. In the fed state, anoxia and potassium cyanide caused a marked decrease in the transport characteristics.
[Europe-Finner GN; Biosci Rep 4 (10): 843-50 (1984)]**PEER REVIEWED**

The effect of cyanide on whole-brain calcium levels was determined in mice administered potassium cyanide and correlated with the neurotoxic signs manifested during acute cyanide poisoning. Potassium cyanide (10 mg/kg, sc) significantly increased whole-brain total calcium levels from 48.1 + or - 1.8 to 66.5 + or - 3.9 micrograms/g dry wt within 15 min after administration. They remained elevated for 3 hr and returned to control readings after 12 hr. Dose-response studies revealed potassium cyanide at doses of 10-15 mg/kg, produced significant elevations of whole-brain calcium 30 min after administration. No measurable effect was obtained from lower doses which suggested a threshold effect. Pretreatment 15 min before potassium cyanide with diltiazem, a calcium channel blocker, prevented the cyanide induced rise in whole-brain total calcium. Cyanide induced tremors, which are centrally mediated symptoms of intoxication, were quantified and correlated with the observed changes in whole-brain calcium. Tremors were detected at 10 and 12 mg/kg potassium cyanide and peak intensity was observed at 15 min postcyanide. Pretreatment with diltiazem markedly attenuated the cyanide induced tremors. It appears that a correlation exists between cyanide induced change in whole-brain calcium and tremors. This study suggests that intraneuronal calcium may play an important role in mediating cyanide neurotoxicity and calcium channel blocking agents may be useful in limiting the severity of the centrally mediated symptoms of acute cyanide intoxication.
[Johnson JD et al; Toxicol Appl Pharmacol 84 (3): 464-69 (1986)]**PEER REVIEWED**

A starfish sperm bioassay for detecting chemical pollutants is described. Potassium cyanide and mercurous chloride inhibited oxygen consumption of spermatozoa by 50% at 0.07 ng/ml and 0.3 ng/ml respectively.
[Mahadevan MM; Experientia 42 (1): 85-86 (1986)]**PEER REVIEWED**

Cyanide (2 mM), an inhibitor of cytochrome oxidase, diminished p-nitroanisole O-demethylation by 50-75% in perfused livers from normal and phenobarbital-treated rats, but had much less effect on hepatic microsomal p-nitroanisole O-demethylation. The inhibition was also observed in livers where the activity of the pentose phosphate shunt was abolished by pretreatment with 6-aminonicotinamide. Cyanide infusion decreased hepatic ATP/ADP ratios and cellular concentrations of glutamate, alpha-ketoglutarate, and isocitrate, but caused an increase in the NADP+/NADPH ratio. Rates of NADPH generation via the pentose phosphate shunt were unchanged by cyanide, and hepatic concentrations of glucose 6-phosphate were markedly increased by cyanide. Thus, inhibition of p-nitroanisole metabolites could not be explained solely by a direct interaction of cyanide with mixed-function oxidases or diminished NADPH generation via the pentose cycle. Apparently cyanide inhibits mixed-function oxidation in intact cells by diminishing the generation of NADPH from sources other than the pentose cycle. Further, these data are consistent with the hypothesis that some NADPH for mixed-function oxidation arises from cyanide-sensitive mitochondrial sources.
[Reinke LA et al; Arch Biochem Biophys 225 (1): 313-19 (1983)]**PEER REVIEWED**

IN THE CASE OF HYDROCYANIC ACID AND CYANIDES /IN VERY HIGH DOSES/, DEATH USUALLY OCCURS /IN ANIMALS/ WITHIN A FEW SECONDS: THERE MAY BE CONVULSIONS, PARALYSIS, STUPOR, & CESSATION OF RESPIRATION BEFORE THAT OF HEARTBEATS. /CYANIDES/
[Clarke, M. L., D. G. Harvey and D. J. Humphreys. Veterinary Toxicology. 2nd ed. London: Bailliere Tindall, 1981. 176]**PEER REVIEWED**

... IF ... ANIMALS ... HAVE EATEN CYANOGENIC PLANTS, CLINICAL SIGNS MAY VARY FROM MILD TACHYPNEA & APPARENT ANXIETY TO SEVERE PANTING, GASPING, & BEHAVIORAL ALARM. OTHER SIGNS INCL SALIVATION, MUSCLE TREMORS, LACRIMATION, URINATION & DEFECATION, SEVERE COLIC, EMESIS, PROSTRATION, ... CLONIC CONVULSIONS, MYDRIASIS, & RAPID DEATH. ... MUCOUS MEMBRANES ARE ... PINK & BLOOD IS CHERRY RED & MAY NOT CLOT. RED COLOR IS DUE TO HYPEROXYGENATION THAT OCCURS WHILE THE ANIMAL IS DYING. THERE MAY BE AGONAL HEMORRHAGES ON HEART. GI TRACT & LUNG MAY HAVE CONGESTION & PETECHIAL HEMORRHAGES. /CYANOGENIC PLANTS/
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 961]**PEER REVIEWED**

Except for the more sensitive invertebrate species, such as Daphnia pulex and Gammarus pseudolimnaeus, invertebrate species are usually more tolerant of cyanide than are freshwater fish species, which have most acute values clustered between 50 to 200 ug/l. A long-term survival and two life cycle test with fish gave chronic values of 7.9, 14, and 16 ug/l, respectively, with Gammarus pseudolimnaeus being comparable to fish in sensitivity and isopods being considerably more tolerant. /Free cyanide: HCN and CN-/
[USEPA; Ambient Water Quality Criteria Doc: Cyanides p.B-6 (1980) EPA 440/5-80-037]**PEER REVIEWED**

... /THERE IS A/ COMBINED EFFECT OF PULMONARY EDEMA AND THE INTERFERENCE OF CELLULAR METABOLISM BY THE CYANIDE ION. /CYANIDE ION/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 4861]**PEER REVIEWED**

Lipid peroxidation of brain lipids as determined by the conjugated diene method was observed in mice following administration of sublethal doses of potassium cyanide (KCN). Conjugated diene production was dose and time dependent; 10 mg/kg KCN produced detectable levels of conjugated dienes at 30 min post cyanide, whereas, 15 mg/kg produced marked levels of conjugated dienes over a 10-60 min period after KCN. Pretreatment of mice with either diltiazem (600 micrograms/kg, iv) or allopurinol (255 mg/kg, iv) blocked the generation of conjugated dienes.
[Johnson JD et al; Toxicol 46 (1): 21-8 (1987)]**PEER REVIEWED**

The effect of cyanide on the active intracellular calcium pool was studied in a cultured neurosecretorycell line, PC12, derived from a rat pheochromocytoma. Cells were cultured and loaded with Quinn-II. Potassium cyanide (KCN) was added to the cultures at concentrations from 10(-4) molar to 10(-2) molar and the intracellular calcium concn was measured. Results showed that KCN produced a rise in cytosolic calcium which was dose dependent. Concn of KCN below 10(-4) molar did not produce measurable increases. The effect of KCN on cell viability was assessed using trypan blue exclusion. No effect was seen at the lower doses of KCN, but at 10(-2) molar a significant decrease in live cells was observed after 30 mins.
[Johnson JD et al; Toxicol Appl Pharmacol 88 (2): 217-24 (1987)]**PEER REVIEWED**

Brain cytochrome responses to carbon monoxide and cyanide were studied in rats. Male Sprague-Dawley rats were surgically prepared for in vivo brain differential reflectance spectrophometry. After preparation, they were intravenously infused with potassium cyanide at rates of 0.25 to 0.50 mg/kg/min, allowed to recover, and then exposed to gas mixtures containing 0,1,3 or 5 percent carbon monoxide in oxygen. Some animals were pretreated with antimycin-A. Cortical spectra were obtained and cytochrome reduction/oxidation changes were monitored. In an in vitro experiment, hemoglobin free rat brain slices were incubated with potassium cyanide and carbon monoxide. Cytochrome responses were investigated by transmission spectrophotometry. In vivo, cyanide infusion caused reversible increases in the reduction level of cytochrome-a3, measured at 605 to 620 nm. The oxidation/reduction state of b-type cytochromes, monitored at 564 to 575 nm, remained stable during most cyanide infusions. Reduction responses to cyanide were seen after exposure to 1 to 5 percent carbon monoxide. The a3-type and c-type cytochromes did not increase their reduction levels during exposure to 5 percent carbon monoxide. In vitro, b-type cytochromes were stable when exposed to cyanide. After reduction with carbon monoxide, a 445 nm spectral component was found that bound carbon monoxide in the presence of 1 mM potassium cyanide.
[Piantadosi CA et al; J Appl Physiol 62 (3): 1277-84 (1987)]**PEER REVIEWED**

Brain cytochrome oxidase activity was measured after the in vitro addition of potassium cyanide (KCN) or sodium nitroprusside. Activity of cytochrome oxidase was sensitive to KCN; however, this activity was unaffected by sodium nitroprusside. In sodium nitroprusside and KCN treated animals brain cytochrome oxidase activities were measured. At 3 min after sodium nitroprusside injection, inhibition of the enzymatic activity was the same as 1 min after KCN injection. Time to death for sodium nitroprusside treated animals was longer than for KCN treated animals.
[Norris JC, Hume AS; Br J Anaesth 59 (2): 236-9 (1987)]**PEER REVIEWED**

10 MG/KG IP POTASSIUM CYANIDE (KCN) DECR CYTOCHROME OXIDASE ACTIVITY IN MOUSE LIVER & BRAIN. WHEN ANIMALS WERE PRETREATED WITH SODIUM THIOSULFATE & SODIUM NITRITE, KCN INHIBITED BRAIN CYTOCHROME OXIDASE IN CONTRAST TO NO INHIBITION OF LIVER CYTOCHROME OXIDASE.
[ISOM GE ET AL; BIOCHEM PHARMACOL 25 (5): 605-8 (1976)]**PEER REVIEWED**

The cyanide ion is detoxified so effectively if intake is gradual that rats were able to consume potassium cyanide at a rate of 250 mg/kg/day without injury when the compound was mixed evenly into their dry diet.
[Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc., 1991. 646]**PEER REVIEWED**

Non-Human Toxicity Values:

LD50 Rat oral 5 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Rat ip 4 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Rat sc 9 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Rat iv 3600 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Mouse oral 8500 ug/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Mouse ip 5991 ug/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 LD50 Mouse sc 6500 ug/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Mouse iv 2600 ug/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Dog sc 6 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Dog iv 5 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD Rabbit oral 5 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Rabbit sc 4 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Rabbit im 3256 ug/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Rabbit oc 7870 ug/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

LD50 Guinea pig im 4 mg/kg
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

Inorganic cyanides are acutely toxic compounds, for example, the LD50 in the rat is ... 10 mg/kg for potassium cyanide (KCN).
[Lunn, G., E.B. Sansone. Destruction of Hazardous Chemicals in the Laboratory. New York, NY: John Wiley & Sons, Inc. 1994. 133]**PEER REVIEWED**

Metabolism/Pharmacokinetics:

Metabolism/Metabolites:

... CYANIDE ION IS CONJUGATED WITH SULFUR TO FORM THIOCYANATE. ... CONJUGATION IS CATALYZED BY ... RHODANESE WHICH IS WIDELY DISTRIBUTED IN MOST ANIMAL TISSUES ... /LIVER/ PARTICULARLY ACTIVE. ... RHODANESE MECHANISM IS CAPABLE OF DETOXICATING ONLY LIMITED AMT OF CYANIDE, SUCH AS ARE FORMED DURING NORMAL METAB. /ANOTHER SULFUR DONOR IS 3-MERCAPTOPYRUVATE. THE ENZYME, MERCAPTOSULFUR TRANSFERASE IS LOCALIZED IN CYTOSOL./ /CYANIDE/
[Parke, D. V. The Biochemistry of Foreign Compounds. Oxford: Pergamon Press, 1968. 96]**PEER REVIEWED**

THE EXCRETION OF THIOCYANATE FOLLOWING THE ADMINISTRATION OF EQUITOXIC DOSES OF CYANIDE TO UNPROTECTED MICE AND TO ANIMALS PRETREATED WITH VARIOUS CYANIDE ANTIDOTES WAS STUDIED. CYANIDE GIVEN ALONE OR TO ANIMALS PRETREATED WITH THIOSULFATE IS EXTENSIVELY CONVERTED TO THIOCYANATE. THE CYANIDE IS EXCRETED IN THE URINE, AS DEMONSTRATED BY DETECTION OF HIGH AMOUNTS OF COBALT IONS AND STRONGLY COMPLEX-BOUND CYANIDE IN THE URINE. A METHOD FOR THE DETERMINATION OF CYANIDE PRESENT AS COBALT CYANIDE COMPLEXES IS DESCRIBED AND ITS FORENSIC APPLICATION IS PROPOSED.
[FRANKENBERG L, SORBO B; ARCH TOXICOL 33 (2): 81-9 (1975)]**PEER REVIEWED**

Aliphatic nitriles have been postulated to manifest their toxicity through cyanide (CN) liberation. The signs of toxicity and effect of equitoxic LD50 doses of saturated and unsaturated aliphatic mono- and dinitriles on tissue and blood CN levels, tissue glutathione levels and cytochrome c oxidase activities were studied in rats. Signs of toxicity were classified into cholinomimetic effects observed with unsaturated nitriles and CNS effects observed with saturated potassium cyanide. Hepatic and blood CN levels 1 hr after treatment were highest following malononitrile and decreased in the order of propionitrile > potassium cyanide > butyronitrile > acrylonitrile > allylcyanide > fumaronitrile > acetonitrile. The order differed in brain where potassium cyanide preceded malononitrile and PCN. Hepatic and cytochrome c oxidase were significantly inhibited and corresponded to their CN levels. No significant inhibition of cytochrome c oxidase was observed in vitro. Acrylonitrile was the only nitrile which significantly reduced tissue GSH levels. Toxic expression of aliphatic nitriles depended on CN release and their degree of unsaturation. With unsaturated aliphatic nitriles CN release played a minimal role in their toxicity. /Cyanides/
[Ahmed AE, Farooqui M YH; Toxicol Lett (AMST) 12 (2-3): 157-64 (1982)]**PEER REVIEWED**

Rhizopus oryzae, a mucoraceous fungus associated with the postharvest spoilage of cassava was found to effectively metabolize cyanide. Degradation of cyanogenic glycosides of cassava by R oryzae was studied by growing the organism in potato dextrose broth with and without linarmarin and potassium cyanide. The influence of adaptation of the organism to low and high cyanide concentrations on both growth and the release of extracellular rhodanese into cyanide containing media was studied. Nonadapted cultures of R oryzae grow poorly when compared with the cyanide adapted cultures. However non-adapted R oryzae cultures released large quantities of rhodanese when compared with the adapted ones. Potassium cyanide (1.0 mM) was found to be an efficient inducer of rhodanese whereas potassium cyanide (5.0 mM) repressed the release of rhodanese. A significant inductive effect was produced by thiosulphate and thiocyanate.
[Padmaja G et al; Can J Microbiol 31 (8): 663-69 (1985)]**PEER REVIEWED**

Acute toxicity and metabolism of 7 dinitriles in mice was studied in relation to the chemical structures. The oral LD50 for each nitrile was detected under different conditions for mice pretreated with either carbon tetrachloride (CCl4) or olive oil. All test nitriles were metabolized into cyanide in vivo and in vitro. The cyanide level was variable among the compounds (0.35-0.74 ug cyanide/g brain) at death in the brains of mice, the level from malononitrile and adiponitrile being comparable to that found in mice killed by dosing with potassium cyanide. After receiving each nitrile, the mean survival time of mice pretreated with CCl4 was prolonged and their brain cyanide level decreased when compared with the corresponding control. With malononitrile, the former did not significantly change and the latter decreased slightly. Brain cyanide levels of control mice at death showed a peak at the lower log P region, whereas those of CCl4 pretreated animals remained lower independently of log P, with the exception of malononitrile. Microsomal metabolism of nitriles to cyanide was greatly inhibited when microsomes were prepared from livers of mice pretreated with CCl4. The relationship between log (1/LD50-CCl4), LD50 in mice pretreated with CCl4, and log P fits a parabolic plot. /Cyanides/
[Tanii H et al; Arch Toxicol 57 (2): 88-93 (1985)]**PEER REVIEWED**

/ONE OF/ THE MAJOR MECHANISM/S/ FOR REMOVING CYANIDE FROM THE BODY IS ITS ENZYMATIC CONVERSION, BY THE MITOCHONDRIAL ENZYME RHODANESE (TRANSSULFURASE), TO THIOCYANATE, WHICH IS RELATIVELY ... /LESS TOXIC/. /CYANIDE/
[Gilman, A.G., L.S.Goodman, and A. Gilman. (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 7th ed. New York: Macmillan Publishing Co., Inc., 1985. 1643]**PEER REVIEWED**

RUMINANTS ARE MORE SUSCEPTIBLE TO POISONING BY CYANOGENIC PLANTS /SRP: WHICH RELEASE HYDROGEN CYANIDE/ THAN ARE HORSES & PIGS ... /CYANOGENIC PLANTS/
[Clarke, M. L., D. G. Harvey and D. J. Humphreys. Veterinary Toxicology. 2nd ed. London: Bailliere Tindall, 1981. 176]**PEER REVIEWED**

FACTORS THAT INCR LIKELIHOOD OF HYDROGEN CYANIDE POISONING FROM INGESTION OF CYANOGENIC PLANTS INCLUDE: (1) LARGE AMT OF FREE HYDROGEN CYANIDE & CYANOGENIC GLYCOSIDE IN PLANT, (2) RAPID INGESTION; (3) INGESTION OF A LARGE AMT OF PLANT, & (4) RUMINAL PH & MICROFLORA THAT CONTINUE TO HYDROLYZE GLYCOSIDE /SRP: TO RELEASE HYDROGEN CYANIDE/. RAPID INTAKE OF PLANT ... EQUIV TO ABOUT 4 MG HYDROGEN CYANIDE/KG OF BODY WT IS CONSIDERED TO BE LETHAL AMOUNT OF PLANT MATERIAL. ... /CYANOGENIC PLANTS/
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 961]**PEER REVIEWED**

The role of oxidative metabolism in the disposition of potassium cyanide, was investigated in mice administered potassium cyanide (4.6 mg/kg, sc) containing 4.5 uCi (14)C-potassium cyanide. The expired pulmonary metabolites, (14)C-hydrocyanic acid and (14)CO2, carbon dioxide were collected and analyzed. Approximately 1% and 2% of the potassium cyanide dose was expired as (14)C-hydrocyanic acid and (14) carbon dioxide respectively. Expiration of the pulmonary metabolites was decreased following pretreatment with sodium nitrite, sodium thiosulfate, oxygen, or a combination of cyanide antidotes. Treatment with hydrogen peroxide lowered the amount of (14)C-hydrocyanic acid expired and did not alter the expiration of (14)carbon dioxide. Treatment with 3-amino-1,2,4-triazole (catalase inhibitor), superoxide dismutase, or diethyldithiocarbamic acid (superoxide dismutase inhibitor) did not change the amount of (14)C-hydrocyanic acid expired. However, superoxide dismutase significantly increased the amount of (14)CO2 expired, whereas diethyldithiocarbamic acid decreased (14) carbon dioxide expiration.
[Johnson JD; Toxicology 37 (3-4): 215-24 (1985)]**PEER REVIEWED**

Absorption, Distribution & Excretion:

IN 30 DAYS, 72% OF (14)C FROM IP DOSE OF (14)C-CYANIDE TO MICE WAS EXCRETED IN URINE & FECES, 25% IN EXPIRED AIR, & 3% WAS RETAINED ... PEAK EXCRETION OCCURRED WITHIN 10 MIN IN EXPIRED AIR & WITHIN 6-24 HR IN URINE & FECES. /CYANIDE/
[The Chemical Society. Foreign Compound Metabolism in Mammals. Volume 1: A Review of the Literature Published Between 1960 and 1969. London: The Chemical Society, 1970. 94]**PEER REVIEWED**

CYANIDE ION IS READILY ABSORBED AFTER ORAL OR PARENTERAL ADMIN. PROLONGED LOCAL CONTACT WITH CYANIDE SOLN ... MAY RESULT IN ABSORPTION OF TOXIC AMT THROUGH SKIN. PART OF ABSORBED CYANIDE IS EXCRETED UNCHANGED BY THE LUNG. LARGER PORTION ... CONVERTED BY SULFURTRANSFERASE TO RELATIVELY NONTOXIC THIOCYANATE ION. /CYANIDE/
[Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975. 904]**PEER REVIEWED**

AFTER IM INJECTION OF POTASSIUM CYANIDE AT 10 MG(CN)/KG IN SHEEP, THE CN CONCN IN WHOLE BLOOD WAS 2-3 TIMES AS HIGH AS IN PLASMA, SERUM, CEREBROSPINAL FLUID, CAUDATE NUCLEUS & WHITE MATTER.
[BALLANTYNE B; J FORENSIC SCI SOC 15 (1): 51-56 (1975)]**PEER REVIEWED**

The excretion of (14)C-labeled cyanide in rats exposed to chronic intake of potassium cyanide was studied in rats exposed to daily intake of labeled potassium cyanide in the diet for 6 weeks. Urinary excretion was the main route of elimination of cyanide carbon in these rats, accounting for 83% of the total excreted radioactivity in 12 hr and 89% of the total excreted radioactivity in 24 hr. The major excretion metabolite of cyanide in urine was thiocyanate, and this metabolite accounted for 71 and 79% of the total urinary activity in 12 hr and 24 hr, respectively. When these results were compared with those observed for control rats, it was clear that the mode of elimination of cyanide carbon in both urine and breath was not altered by the chronic intake of cyanide.
[Okoh PN; Toxicol Appl Pharmacol 70 (2): 335-39 (1983)]**PEER REVIEWED**

CYANIDES ARE RAPIDLY ABSORBED FROM SKIN & ALL MUCOSAL SURFACES & ARE MOST DANGEROUS WHEN INHALED, BECAUSE TOXIC AMT ARE ABSORBED WITH GREAT RAPIDITY THROUGH BRONCHIAL MUCOSA & ALVEOLI. /CYANIDES/
[Haddad, L.M. and Winchester, J.F. Clinical Management of Poisoning and Drug Overdosage. Philadelphia, PA: W.B. Saunders Co., 1983. 745]**PEER REVIEWED**

Cyanide is distributed to all organs and tissues via the blood, where its concn in red cells is greater than that in plasma by a factor of two or three. Presumably, the accumulation of cyanide in erythrocytes is a reflection of its binding to methemoglobin. /Cyanides/
[USEPA; Ambient Water Quality Criteria Doc: Cyanides p.C-9 (1980) EPA 440/5-80-037]**PEER REVIEWED**

Once absorbed into the body, cyanide can form complexes with heavy metal ions. /Cyanide/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.45 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Inhalation of cyanide salt dusts is dangerous because the cyanide will dissolve on contact with most mucous membranes and be absorbed into the bloodstream. /Cyanide salts/
[USEPA; Ambient Water Quality Criteria Doc: Cyanides p.C-7 (1980) EPA 440/5-80-037]**PEER REVIEWED**

Cyanide is concentrated in red blood cells at a RBC/plasma ratio is 100/l. The volume of distribution of cyanide ion is approximately 1.5 l/kg. About 60% if CN- in plasma is protein bound. /Cyanide/
[Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997. 1478]**PEER REVIEWED**

Biological Half-Life:

Half-life for the conversion of cyanide to thiocyanate from a non-lethal dose in man is between 20 min and 1 hr. /Cyanide/
[Feldstein M, Klendshoj NC; J Lab Chin Med 44: 166-70 (1954) as cited in NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.45 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Mechanism of Action:

CYANIDE HAS A VERY HIGH AFFINITY FOR IRON IN FERRIC STATE. WHEN ABSORBED IT REACTS READILY WITH ... IRON OF CYTOCHROME OXIDASE IN MITOCHONDRIA; CELLULAR RESPIRATION IS THUS INHIBITED & CYTOTOXIC HYPOXIA RESULTS. SINCE UTILIZATION OF OXYGEN IS BLOCKED, VENOUS BLOOD IS OXYGENATED AND IS ALMOST AS BRIGHT RED AS ARTERIAL BLOOD. RESPIRATION IS STIMULATED BECAUSE CHEMORECEPTIVE CELLS RESPOND AS THEY DO TO DECREASED OXYGEN. A TRANSIENT STAGE OF CNS STIMULATION WITH HYPERPNEA AND HEADACHE IS OBSERVED; FINALLY THERE ARE HYPOXIC CONVULSIONS AND DEATH DUE TO RESPIRATORY ARREST. /CYANIDE/
[Gilman, A.G., L.S.Goodman, and A. Gilman. (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 7th ed. New York: Macmillan Publishing Co., Inc., 1985. 1642]**PEER REVIEWED**

SINGLE DOSES OF CYANIDE PRODUCE ALTERATIONS IN PATTERN OF BRAIN METABOLITES CONSISTENT WITH DECR IN OXIDATIVE METABOLISM & INCR IN GLYCOLYSIS. DECR IN BRAIN GAMMA-AMINOBUTYRIC ACID ... HAVE BEEN ASCRIBED TO CYANIDE INHIBITION OF GLUTAMIC ACID DECARBOXYLASE. /CYANIDE/
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-126]**PEER REVIEWED**

THE CORTICAL GRAY MATTER, HIPPOCAMPUS (H1), CORPORA STRIATA, & SUBSTANTIA NIGRA ARE COMMONLY AFFECTED /BY CYANIDE/. ... CYANIDE ALSO HAS PROPENSITY FOR DAMAGING WHITE MATTER, PARTICULARLY CORPUS CALLOSUM. CYANIDE INHIBITS CYTOCHROME OXIDASE & PRODUCES CYTOTOXIC ANOXIA, BUT ALSO CAUSES HYPOTENSION THROUGH ITS EFFECTS ON HEART. /CYANIDE/
[Doull, J., C.D.Klassen, and M.D. Amdur (eds.). Casarett and Doull's Toxicology. 3rd ed., New York: Macmillan Co., Inc., 1986. 372]**PEER REVIEWED**

The cyanide ion (CN-) forms complexes with a number of other chemicals (eg, in tissues) and has a strong affinity for cobalt. /Cyanide ion/
[Booth, N.H., L.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics. 5th ed. Ames, Iowa: Iowa State University Press, 1982. 961]**PEER REVIEWED**

The effect of cyanide on whole-brain calcium levels was determined in mice administered potassium cyanide and correlated with the neurotoxic signs manifested during acute cyanide poisoning. potassium cyanide (10 mg/kg, sc) significantly increased whole-brain total calcium levels from 48.1 + or - 1.8 to 66.5 + or - 3.9 micrograms/g dry wt within 15 min after administration. They remained elevated for 3 hr and returned to control readings after 12 hr. Dose-response studies revealed potassium cyanide at doses of 10-15 mg/kg, produced significant elevations of whole-brain calcium 30 min after administration. No measureable effect was obtained from lower doses which suggested a threshold effect. Pretreatment 15 min before potassium cyanide with diltiazem, a calcium channel blocker, prevented the cyanide induced rise in whole-brain total calcium. Cyanide induced tremors, which are centrally mediated symptoms of intoxication, were quantified and correlated with the observed changes in whole-brain calcium. Tremors were detected at 10 and 12 mg/kg potassium cyanide and peak intensity was observed at 15 min postcyanide. Pretreatment with diltiazem markedly attenuated the cyanide induced tremors.
[Johnson JD et al; Toxicol Appl Pharmacol 84 (3): 464-69 (1986)]**PEER REVIEWED**

/CYANIDE/ ... REACTS ... WITH TRIVALENT IRON OF CYTOCHROME OXIDASE IN MITOCHONDRIA TO FORM THE CYTOCHROME OXIDASE-CN COMPLEX ... THE CYTOCHROME-OXIDASE-CN COMPLEX IS DISSOCIABLE; THE MITOCHONDRIAL ENZYME SULFURTRANSFERASE ... MEDIATES TRANSFER OF SULFUR FROM THIOSULFATE TO CYANIDE ION. THUS, THIOCYANATE IS FORMED ... KINETIC STUDIES INDICATE THAT THE CLEAVAGE OF THE THIOSULFATE SULFUR-SULFUR BOND IS THE RATE-LIMITING STEP IN THIS REACTION. RELATIVELY MINOR PATHWAYS INCL COMBINATION WITH CYSTINE TO FORM 2-IMINO-THIAZOLIDINE-4-CARBOXYLIC ACID, OXIDATION TO CARBON DIOXIDE & FORMATE, & FORMATION OF CYANOCOBALAMIN. /CYANIDE/
[Gilman, A.G., L.S.Goodman, and A. Gilman. (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 7th ed. New York: Macmillan Publishing Co., Inc., 1985. 1642]**PEER REVIEWED**

Interactions:

CHLORPROMAZINE ANTAGONISM OF CYANIDE INTOXICATION WAS POTENTIATED BY SODIUM THIOSULFATE. CHLORPROMAZINE & SODIUM NITRITE DID NOT PROTECT AGAINST KCN LETHALITY BETTER THAN NITRITE ALONE.
[DODSON RA ET AL; PROC WEST PHARMACOL SOC 18: 348-50 (1975)]**PEER REVIEWED**

To elucidate the interaction of carbon monoxide (CO) and cyanide, the fluorescence which represents the intracellular reduced pyridine nucleotide was measured on the rabbit kidney surface in situ. Various doses of potassium cyanide, 2-8 umol/kg, were administered intravenously with and without inhalation of 1, 2 and 3% carbon monoxide via a respirator. The dose-response relationship between potassium cyanide and the fluorescence increase fitted a salient sigmoid curve with a steep slope, and carbon monoxide was potent to increase fluorescence independently and shifted the dose response curve for potassium cyanide to the left. The combined effect of carbon monoxide and potassium cyanide was of a critical dose for intracellular respiration, it had the appearance of synergism.
[Takano T, Miyazaki Y; Jpn J Hyg 36 (5): 811-15 (1981)]**PEER REVIEWED**

Previous reports indicated that prophylactic protection against cyanide intoxication in mice can be enhanced by administration of chlorpromazine when it is given with sodium thiosulfate. The mechanism of potentiation of sodium thiosulfate by chlorpromazine was studied alone and in combination with sodium nitrite. Although chlorpromazine was found to induce a hypothermic response, the mechanism of enhancement of the antagonism of cyanide by chlorpromazine does not correlate with the hypothermia produced. Various other possible mechanisms were investigated, such as rate of methemoglobin formation, enzymatic activity of rhodanese and cytochrome oxidase, and alpha-adrenergic blockade. The alpha-adrenergic blocking properties of chlorpromazine may provide a basis for its antidotal effect, since this protective effect can be reversed with an alpha-antagonist, methoxamine. /Cyanide/
[Kong A et al; Toxicol Appl Pharmacol 71 (3): 407-13 (1983)]**PEER REVIEWED**

The interaction of 7 beta-adrenergic blocking agents with salbutamol and isoproterenol was studied in the potassium cyanide test in rats. Salbutamol (albuterol) was used at a dose that provided protection from potassium cyanide (KCN) lethality and isoproterenol at an overdose that failed to protect, presumably because of latent cardiotoxicity. Salbutamol-induced protection was abolished by drugs at the following doses (sc, mg/kg); timolol (0.0085), bunolol (0.010), propranolol (0.038), pindolol (0.15), metoprolol (3.93), atenolol (5.69), and practolol (>10.0). Survival was restored dose dependently in isoproterenol-overdosed rats only by atenolol (0.44), practolol (0.51) and metoprolol (1.06). The cardioselectivity ratio (ie, salbutamol antagonism/isoproterenol antagonism) for these 3 compounds was as follows: practolol (>19.6), atenolol (12.9), and metoprolol (3.82).
[Awouters F et al; Drug Dev Res 5 (3): 217-24 (1985)]**PEER REVIEWED**

Cysteine, a sulfur-containing amino acid, is required to metabolize ascorbic acid (as ascorbate sulfate) and detoxify cyanide (to thiocyanate). In guinea pigs, concomitant use of laetrile (a cyanogenic glycoside) and ascorbic acid (in large doses) decreases the detoxification of cyanide derived from laetrile through diminishing the availability of cysteine, but not impairing hepatic rhodanese activity, which is involved in the detoxification of cyanide to thiocyanate. These results agree with the symptoms of a sublethal dose of potassium cyanide toxicity manifested by the animals.
[Basu TK; Can J Physiol Pharmacol 61 (11): 1426-30 (1983)]**PEER REVIEWED**

Flunarizine is a calcium entry blocking drug possessing antihypoxic activity in animal models of cerebral and peripheral ischemia-anoxia and has clinical usefulness in circulatory disorders of both central and peripheral origin. This report compares the activity of flunarizine and verapamil, another calcium entry blocking drug, on the central nervous system (CNS) and peripheral consequences of cytotoxic hypoxia induced by high and low doses of KCN. The lethal effect of potassium cyanide (6 mg/kg, ip) in rats was prevented by orally administered flunarizine (ED50= 12 mg/kg with four hr pretreatment) but not by verapamil (at oral doses up to 80 mg/kg with one hr pretreatment). Since the lethal effect of KCN involves failure of respiration at the CNS level, these results suggest that flunarizine protects against the hypoxic effect of the cyanide ion by an action in brain tissue. We found also that the stimulant effect of low intravenous doses (0.5 mg/kg/min) of KCN upon respiration rate was not altered in pentobarbital- and chloralose-anesthetized rats treated with oral doses of flunarizine up to 80 mg/kg (with four hr pretreatment). In contrast, KCN-stimulated respiration rate in pentobarbital anesthetized rats was significantly attenuated by verapamil (20 and 40 mg/kg, po with one hr pretreatment). Since low doses of the cyanide ion render respiration quicker and deeper by an action on chemoreceptive cells in peripheral arteries, the effect of verapamil against the hypoxic effect of KCN is mediated by an action in the periphery.
[Dubinsky B et al; Life Sci 34 (13): 1299-306 (1984)]**PEER REVIEWED**

The anti-anoxic effect of sufoxazine was investigated in various cerebral anoxia models with mice, in comparison with those of various cerebroactive drugs. Sufoxazine reduced dose-dependently the duration of coma induced by a sublethal dose of potassium cyanide (1.8 mg/kg, iv) significantly stimulating recovery from the coma at 5 mg/kg, ip and 30 mg/kg, po. It also protected against a lethal dose of KCN (2.5 mg/kg, iv). These findings suggest that sufoxazine has an anti-anoxic action superior to those of the other cerebroactive drugs used.
[Izumi N, Yasuda H; Nippon Yakurigaku Zasshi 86 (4): 323-28 (1985)]**PEER REVIEWED**

Cyanide intoxication in mice can be antagonized by the opiate antagonist, (-)naloxone HCl, alone or in combination with sodium thiosulfate and/or sodium nitrite. Potency ratios, derived from LD50 values, were compared in groups of mice pretreated with sodium nitrite (sc, 100 mg/kg), sodium thiosulfate (ip, 1 g/kg), and (-)naloxone HCl (sc, 10 mg/kg) either alone or in various combinations. These results indicate that naloxone HCl provides a significant protection against the lethal effects of potassium cyanide. The protective effect of sodium thiosulfate, but not sodium nitrite, was enhanced with (-)naloxone HCl. The combined administration of sodium nitrite and sodium thiosulfate was further enhanced with (-)naloxone HCl. The protective effect of naloxone HCl against the lethal effect of cyanide appears to be restricted to the (-)stereoisomer, as the (+)stereoisomer, the inactive opiate antagonist, is also inactive in protecting against the lethal effects of cyanide.
[Leung P et al; Toxicol Appl Pharmacol 83 (3): 525-30 (1986)]**PEER REVIEWED**

Protective effects of OP-2507 (15-cis-(4-propylcyclohexyl)16,17,18,19,20-pentanor-9-deoxy-9 alpha, 6-nitrilo-PGF1 methyl ester) against cerebral anoxia and edema were investigated in a variety of experimental models in mice and rats. OP-2507 given sc or po led to a consistent and dose-dependent prolongation of survival time against cerebral anoxia in hypobaric and normobaric hypoxia, potassium cyanide induced anoxia.
[Masuda Y et al; Eur J Pharmacol 123 (3): 335-44 (1986)]**PEER REVIEWED**

Pyruvic acid, an alpha-ketocarboxylic acid, has been shown to antagonize the lethal effects of cyanide. It is suggested that its mechanism of action rests in its ability to react with or "bind" cyanide. alpha-Ketoglutaric acid increased the LD50 value of cyanide (6.7 mg/kg) by a factor of five, a value statistically equivalent to that ascertained in mice pretreated with sodium thiosulfate and sodium nitrite. The combination of alpha-ketoglutaric acid and sodium thiosulfate increased the LD50 value of cyanide to 101 mg/kg. Addition of sodium nitrite to the alpha-ketoglutaric acid/sodium thiosulfate regimen increased the LD50 value of cyanide to 119 mg/kg. Unlike sodium nitrite, no induction of methemoglobin formation was observed with alpha-ketoglutaric acid pretreatment.
[Moore SJ et al; Toxicol Appl Pharmacol 82 (1): 40-44 (1986)]**PEER REVIEWED**

The activity of a series of 9 beta-adrenergic agonists was studied in the potassium cyanide (5.00 mg/kg iv) and the compound 48/80 (0.50 mg/kg iv) lethality tests in rats. All compounds were active in both tests. The ED50 values in mg/kg for protection against KCN-induced lethality were as follows: clenbuterol (0.0047), zinterol (0.0055), hexoprenaline (0.0093), fenoterol (0.012), isoproterenol (0.014), colterol (0.019), salbutamol (0.028), terbutaline (0.14), and metaproterenol (0.33). By increasing the dose levels, the protective activity of some of the compounds disappeared and LD50s at which lethality to KCN was restored could be calculated. The protective dose range, which is defined as the ratio of the LD50 and the ED50, greatly varies among the test compounds. Protection from KCN induced lethality seems to be due to an increased tissue perfusion and to occur as long as myocardial activity is not markedly changed from normal by the test compound.
[Niemegeers CJ E et al; Drug Dev Res 5 (3): 225-31 (1985)]**PEER REVIEWED**

The purpose of this study was to investigate lethality induced by low concentrations of carbon monoxide and cyanide. Male ICR mice were used in these studies. Doses of potassium cyanide (4-9 mg/kg, ip) were administered to animals pretreated for 3 min with either air or carbon monoxide (0.63-0.66%). From these data the LD50 value of potassium cyanide (KCN) was determined in these animals pretreated with either air or carbon monoxide. A significantly lower LD50 value for KCN was found in carbon monoxide pretreated animals as compared to air pretreated animals. In another series of experiments, animals were pretreated with either saline or KCN (1.00-6.35 mg/kg ip) and then placed in the chamber containing a carbon monoxide atmosphere (0.325-0.375%). Ten to 20% of saline pretreated animals were dead at the end of the monitoring period. Sublethal doses of KCN (3.5-6.35 mg/kg ip) produced a synergistic lethality as compared to the saline pretreated animals. Blood was analyzed for carbon monoxide and cyanide content to determine if there were any changes that could explain this augmented lethality. There was no difference in carbon monoxide or cyanide blood concentration between these treatment groups.
[Norris JC et al; Toxicology 40 (2): 121-29 (1986)]**PEER REVIEWED**

Nicergoline (16 mg/kg, ip) prolonged the survival time of mice exposed to hypobaric hyoxia (165 mm Hg); nicergoline (1-16 mg/kg ip, or 16-64 mg/kg orally) also protected from a lethal dose of potassium cyanide (3 mg/kg iv). Nicergoline (8-128 ug/kg iv) dose-dependently shortened the duration of disappearance of spontaneous EEG in rats exposed to a sublethal dose of KCN (1.5 mg/kg iv) and promoted the recovery from behavioral disorders and disturbance of cerebral energy metabolism in mice exposed to a sublethal dose of KCN. /In vitro/ Nicergoline (100 uM) protected the inhibition of mouse brain cytochrome oxidase activity in the presence of KCN (2 uM).
[Shintomi K et al; Nippon Yakurigaku Zasshi 87 (4): 445-56 (1986)]**PEER REVIEWED**

Pharmacology:

Interactions:

CHLORPROMAZINE ANTAGONISM OF CYANIDE INTOXICATION WAS POTENTIATED BY SODIUM THIOSULFATE. CHLORPROMAZINE & SODIUM NITRITE DID NOT PROTECT AGAINST KCN LETHALITY BETTER THAN NITRITE ALONE.
[DODSON RA ET AL; PROC WEST PHARMACOL SOC 18: 348-50 (1975)]**PEER REVIEWED**

To elucidate the interaction of carbon monoxide (CO) and cyanide, the fluorescence which represents the intracellular reduced pyridine nucleotide was measured on the rabbit kidney surface in situ. Various doses of potassium cyanide, 2-8 umol/kg, were administered intravenously with and without inhalation of 1, 2 and 3% carbon monoxide via a respirator. The dose-response relationship between potassium cyanide and the fluorescence increase fitted a salient sigmoid curve with a steep slope, and carbon monoxide was potent to increase fluorescence independently and shifted the dose response curve for potassium cyanide to the left. The combined effect of carbon monoxide and potassium cyanide was of a critical dose for intracellular respiration, it had the appearance of synergism.
[Takano T, Miyazaki Y; Jpn J Hyg 36 (5): 811-15 (1981)]**PEER REVIEWED**

Previous reports indicated that prophylactic protection against cyanide intoxication in mice can be enhanced by administration of chlorpromazine when it is given with sodium thiosulfate. The mechanism of potentiation of sodium thiosulfate by chlorpromazine was studied alone and in combination with sodium nitrite. Although chlorpromazine was found to induce a hypothermic response, the mechanism of enhancement of the antagonism of cyanide by chlorpromazine does not correlate with the hypothermia produced. Various other possible mechanisms were investigated, such as rate of methemoglobin formation, enzymatic activity of rhodanese and cytochrome oxidase, and alpha-adrenergic blockade. The alpha-adrenergic blocking properties of chlorpromazine may provide a basis for its antidotal effect, since this protective effect can be reversed with an alpha-antagonist, methoxamine. /Cyanide/
[Kong A et al; Toxicol Appl Pharmacol 71 (3): 407-13 (1983)]**PEER REVIEWED**

The interaction of 7 beta-adrenergic blocking agents with salbutamol and isoproterenol was studied in the potassium cyanide test in rats. Salbutamol (albuterol) was used at a dose that provided protection from potassium cyanide (KCN) lethality and isoproterenol at an overdose that failed to protect, presumably because of latent cardiotoxicity. Salbutamol-induced protection was abolished by drugs at the following doses (sc, mg/kg); timolol (0.0085), bunolol (0.010), propranolol (0.038), pindolol (0.15), metoprolol (3.93), atenolol (5.69), and practolol (>10.0). Survival was restored dose dependently in isoproterenol-overdosed rats only by atenolol (0.44), practolol (0.51) and metoprolol (1.06). The cardioselectivity ratio (ie, salbutamol antagonism/isoproterenol antagonism) for these 3 compounds was as follows: practolol (>19.6), atenolol (12.9), and metoprolol (3.82).
[Awouters F et al; Drug Dev Res 5 (3): 217-24 (1985)]**PEER REVIEWED**

Cysteine, a sulfur-containing amino acid, is required to metabolize ascorbic acid (as ascorbate sulfate) and detoxify cyanide (to thiocyanate). In guinea pigs, concomitant use of laetrile (a cyanogenic glycoside) and ascorbic acid (in large doses) decreases the detoxification of cyanide derived from laetrile through diminishing the availability of cysteine, but not impairing hepatic rhodanese activity, which is involved in the detoxification of cyanide to thiocyanate. These results agree with the symptoms of a sublethal dose of potassium cyanide toxicity manifested by the animals.
[Basu TK; Can J Physiol Pharmacol 61 (11): 1426-30 (1983)]**PEER REVIEWED**

Flunarizine is a calcium entry blocking drug possessing antihypoxic activity in animal models of cerebral and peripheral ischemia-anoxia and has clinical usefulness in circulatory disorders of both central and peripheral origin. This report compares the activity of flunarizine and verapamil, another calcium entry blocking drug, on the central nervous system (CNS) and peripheral consequences of cytotoxic hypoxia induced by high and low doses of KCN. The lethal effect of potassium cyanide (6 mg/kg, ip) in rats was prevented by orally administered flunarizine (ED50= 12 mg/kg with four hr pretreatment) but not by verapamil (at oral doses up to 80 mg/kg with one hr pretreatment). Since the lethal effect of KCN involves failure of respiration at the CNS level, these results suggest that flunarizine protects against the hypoxic effect of the cyanide ion by an action in brain tissue. We found also that the stimulant effect of low intravenous doses (0.5 mg/kg/min) of KCN upon respiration rate was not altered in pentobarbital- and chloralose-anesthetized rats treated with oral doses of flunarizine up to 80 mg/kg (with four hr pretreatment). In contrast, KCN-stimulated respiration rate in pentobarbital anesthetized rats was significantly attenuated by verapamil (20 and 40 mg/kg, po with one hr pretreatment). Since low doses of the cyanide ion render respiration quicker and deeper by an action on chemoreceptive cells in peripheral arteries, the effect of verapamil against the hypoxic effect of KCN is mediated by an action in the periphery.
[Dubinsky B et al; Life Sci 34 (13): 1299-306 (1984)]**PEER REVIEWED**

The anti-anoxic effect of sufoxazine was investigated in various cerebral anoxia models with mice, in comparison with those of various cerebroactive drugs. Sufoxazine reduced dose-dependently the duration of coma induced by a sublethal dose of potassium cyanide (1.8 mg/kg, iv) significantly stimulating recovery from the coma at 5 mg/kg, ip and 30 mg/kg, po. It also protected against a lethal dose of KCN (2.5 mg/kg, iv). These findings suggest that sufoxazine has an anti-anoxic action superior to those of the other cerebroactive drugs used.
[Izumi N, Yasuda H; Nippon Yakurigaku Zasshi 86 (4): 323-28 (1985)]**PEER REVIEWED**

Cyanide intoxication in mice can be antagonized by the opiate antagonist, (-)naloxone HCl, alone or in combination with sodium thiosulfate and/or sodium nitrite. Potency ratios, derived from LD50 values, were compared in groups of mice pretreated with sodium nitrite (sc, 100 mg/kg), sodium thiosulfate (ip, 1 g/kg), and (-)naloxone HCl (sc, 10 mg/kg) either alone or in various combinations. These results indicate that naloxone HCl provides a significant protection against the lethal effects of potassium cyanide. The protective effect of sodium thiosulfate, but not sodium nitrite, was enhanced with (-)naloxone HCl. The combined administration of sodium nitrite and sodium thiosulfate was further enhanced with (-)naloxone HCl. The protective effect of naloxone HCl against the lethal effect of cyanide appears to be restricted to the (-)stereoisomer, as the (+)stereoisomer, the inactive opiate antagonist, is also inactive in protecting against the lethal effects of cyanide.
[Leung P et al; Toxicol Appl Pharmacol 83 (3): 525-30 (1986)]**PEER REVIEWED**

Protective effects of OP-2507 (15-cis-(4-propylcyclohexyl)16,17,18,19,20-pentanor-9-deoxy-9 alpha, 6-nitrilo-PGF1 methyl ester) against cerebral anoxia and edema were investigated in a variety of experimental models in mice and rats. OP-2507 given sc or po led to a consistent and dose-dependent prolongation of survival time against cerebral anoxia in hypobaric and normobaric hypoxia, potassium cyanide induced anoxia.
[Masuda Y et al; Eur J Pharmacol 123 (3): 335-44 (1986)]**PEER REVIEWED**

Pyruvic acid, an alpha-ketocarboxylic acid, has been shown to antagonize the lethal effects of cyanide. It is suggested that its mechanism of action rests in its ability to react with or "bind" cyanide. alpha-Ketoglutaric acid increased the LD50 value of cyanide (6.7 mg/kg) by a factor of five, a value statistically equivalent to that ascertained in mice pretreated with sodium thiosulfate and sodium nitrite. The combination of alpha-ketoglutaric acid and sodium thiosulfate increased the LD50 value of cyanide to 101 mg/kg. Addition of sodium nitrite to the alpha-ketoglutaric acid/sodium thiosulfate regimen increased the LD50 value of cyanide to 119 mg/kg. Unlike sodium nitrite, no induction of methemoglobin formation was observed with alpha-ketoglutaric acid pretreatment.
[Moore SJ et al; Toxicol Appl Pharmacol 82 (1): 40-44 (1986)]**PEER REVIEWED**

The activity of a series of 9 beta-adrenergic agonists was studied in the potassium cyanide (5.00 mg/kg iv) and the compound 48/80 (0.50 mg/kg iv) lethality tests in rats. All compounds were active in both tests. The ED50 values in mg/kg for protection against KCN-induced lethality were as follows: clenbuterol (0.0047), zinterol (0.0055), hexoprenaline (0.0093), fenoterol (0.012), isoproterenol (0.014), colterol (0.019), salbutamol (0.028), terbutaline (0.14), and metaproterenol (0.33). By increasing the dose levels, the protective activity of some of the compounds disappeared and LD50s at which lethality to KCN was restored could be calculated. The protective dose range, which is defined as the ratio of the LD50 and the ED50, greatly varies among the test compounds. Protection from KCN induced lethality seems to be due to an increased tissue perfusion and to occur as long as myocardial activity is not markedly changed from normal by the test compound.
[Niemegeers CJ E et al; Drug Dev Res 5 (3): 225-31 (1985)]**PEER REVIEWED**

The purpose of this study was to investigate lethality induced by low concentrations of carbon monoxide and cyanide. Male ICR mice were used in these studies. Doses of potassium cyanide (4-9 mg/kg, ip) were administered to animals pretreated for 3 min with either air or carbon monoxide (0.63-0.66%). From these data the LD50 value of potassium cyanide (KCN) was determined in these animals pretreated with either air or carbon monoxide. A significantly lower LD50 value for KCN was found in carbon monoxide pretreated animals as compared to air pretreated animals. In another series of experiments, animals were pretreated with either saline or KCN (1.00-6.35 mg/kg ip) and then placed in the chamber containing a carbon monoxide atmosphere (0.325-0.375%). Ten to 20% of saline pretreated animals were dead at the end of the monitoring period. Sublethal doses of KCN (3.5-6.35 mg/kg ip) produced a synergistic lethality as compared to the saline pretreated animals. Blood was analyzed for carbon monoxide and cyanide content to determine if there were any changes that could explain this augmented lethality. There was no difference in carbon monoxide or cyanide blood concentration between these treatment groups.
[Norris JC et al; Toxicology 40 (2): 121-29 (1986)]**PEER REVIEWED**

Nicergoline (16 mg/kg, ip) prolonged the survival time of mice exposed to hypobaric hyoxia (165 mm Hg); nicergoline (1-16 mg/kg ip, or 16-64 mg/kg orally) also protected from a lethal dose of potassium cyanide (3 mg/kg iv). Nicergoline (8-128 ug/kg iv) dose-dependently shortened the duration of disappearance of spontaneous EEG in rats exposed to a sublethal dose of KCN (1.5 mg/kg iv) and promoted the recovery from behavioral disorders and disturbance of cerebral energy metabolism in mice exposed to a sublethal dose of KCN. /In vitro/ Nicergoline (100 uM) protected the inhibition of mouse brain cytochrome oxidase activity in the presence of KCN (2 uM).
[Shintomi K et al; Nippon Yakurigaku Zasshi 87 (4): 445-56 (1986)]**PEER REVIEWED**

Environmental Fate & Exposure:

Probable Routes of Human Exposure:

Poisoning may occur by ingestion, absorption through injured skin or inhalation of hydrogen cyanide, liberated by action of carbon dioxide or other acids.
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 1100]**PEER REVIEWED**

... SYMPTOMS OF CHRONIC DISEASE ... REPORTED IN ELECTROPLATERS & SILVER POLISHERS AFTER SEVERAL YEARS OF EXPOSURE. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 575]**PEER REVIEWED**

AMONG FUMIGATORS ... CYANIDE POISONING IS RECOGNIZED ... /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 575]**PEER REVIEWED**

DERMATITIS ... IN WORKERS CHRONICALLY EXPOSED TO CYANIDE SOLN. ELECTROPLATERS SUFFER FROM SUCH IRRITATION. /CYANIDE SOLN/
[Hamilton, A., and H. L. Hardy. Industrial Toxicology. 3rd ed. Acton, Mass.: Publishing Sciences Group, Inc., 1974. 224]**PEER REVIEWED**

Body Burden:

Cyanide is present in normal healthy human organs at concentrations ranging up to 0.5 mg/kg. /Cyanide/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.48 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Natural Pollution Sources:

In bacteria, cyanide production has been observed in Chromobacterium violaceum and certain species of Pseudomonas. /Cyanide/
[Nat'l Research Council Canada; The Effect of Cyanides on Aquatic Organisms with Emphasis Upon Fresh Water Fishes p.47 (1976) NRCC No.19246]**PEER REVIEWED**

Artificial Pollution Sources:

Material containing cyanide compounds disposed of on land may lead to elevated levels of cyanide in underlying strata and in groundwater. /Cyanides/
[Nat'l Research Council Canada; The Effect of Cyanides on Aquatic Organisms with Emphasis Upon Fresh Water Fishes p.49 (1982) NRCC No.19246]**PEER REVIEWED**

Environmental Fate:

Aquatic Fate: The alkali metal salts are very soluble in water, and as a result, they readily dissociate into their respective anions and cations upon release to water. The resulting cyanide ion may then form hydrogen cyanide or react with various metals present in natural water. If the cyanide ion is present in excess, complex metallocyanides may form; however, if metals are prevalent, simple metal cyanides may form. /Alkali metal cyanides/
[DHHS/ATSDR; Toxicological Profile for Cyanide (Draft) p.76 (1/88)]**PEER REVIEWED**

Environmental Standards & Regulations:

FIFRA Requirements:

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA 1988 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Potassium cyanide is found on List C. Case No: 3086; Pesticide type: rodenticide; Case Status: Reregistration Eligibility Decision Approved 9/94, PB95-173514 - OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): potassium cyanide; AI Status: Cancelled - The AI is no longer contained in any registered pesticide product.
[USEPA/OPP; Status of Pesticides in Registration, Reregistration and Special Review p.257 (Spring, 1998) EPA 738-R-98-002]**PEER REVIEWED**

CERCLA Reportable Quantities:

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 10 lb or 4.54 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).
[40 CFR 302.4 (7/1/99)]**PEER REVIEWED**

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Potassium cyanide is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 100 lbs.
[40 CFR 355 (7/1/99)]**PEER REVIEWED**

RCRA Requirements:

P098; As stipulated in 40 CFR 261.33, when potassium cyanide, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to federal and/or state hazardous waste regulations. Also defined as a hazardous waste is any container or inner liner used to hold this waste or any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5(e)).
[40 CFR 261.33 (7/1/99)]**PEER REVIEWED**

/SRP:/ D003; A solid waste containing potassium cyanide may become characterized as a hazardous waste when subjected to testing for reactivity as stipulated in 40 CFR 261.23, and if so characterized, must be managed as a hazardous waste.
[40 CFR 261.23 (7/1/99)]**PEER REVIEWED**

Clean Water Act Requirements:

Potassium cyanide is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.
[40 CFR 116.4 (7/1/99)] **QC REVIEWED**

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Cyanides/
[40 CFR 401.15 (7/1/99)] **QC REVIEWED**

Federal Drinking Water Guidelines:

EPA 200 ug/l /Cyanide ion/
[USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

State Drinking Water Guidelines:

(AZ) ARIZONA 220 ug/l /Cyanide ion/
[USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

(ME) MAINE 154 ug/l /Cyanide ion/
[USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

(MN) MINNESOTA 100 ug/l /Cyanide ion/
[USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

Chemical/Physical Properties:

Molecular Formula:

C-K-N
**PEER REVIEWED**

Molecular Weight:

65.11
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 4-77]**PEER REVIEWED**

Color/Form:

White, granular powder or fused pieces
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

White amorphous lumps or crystalline mass
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 915]**PEER REVIEWED**

White cubic crystals
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 4-77]**PEER REVIEWED**

White, granular or crystalline solid.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 262]**PEER REVIEWED**

Odor:

Faint odor of bitter almonds
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 915]**PEER REVIEWED**

Odor of hydrogen cyanide.
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.49 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Faint almond-like odor.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 262]**PEER REVIEWED**

Melting Point:

634 deg C
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 4-77]**PEER REVIEWED**

Density/Specific Gravity:

1.55 at 20 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 775]**PEER REVIEWED**

pH:

11.0 (0.1 N aq soln)
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

Solubilities:

Sol in 2 parts cold, 1 part boiling water
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

Sol in 2 parts glycerol
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

100 g/100 cc hot water above 176 deg F
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.175 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Sol in 25 parts methanol
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

4.55 g/100 g anhydrous liq ammonia @ -33.9 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

4.91 g/100 g methanol @ 19.5 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

0.57 g/100 g ethanol @ 19.5 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

146 g/l formamide @ 25 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

41 g/100 g hydroxylamine @ 17.5 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

24.24 g/100 g glycerol of specific gravity 1.2561 @ 15.5 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

0.73 g/l phosphorus oxychloride soln @ 20 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

0.017 g/100 g liq sulfur dioxide @ 0 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

0.22 g/100 g dimethylformamide @ 25 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

Spectral Properties:

INDEX OF REFRACTION: 1.410
[Weast, R.C. (ed.) Handbook of Chemistry and Physics, 68th ed. Boca Raton, Florida: CRC Press Inc., 1987-1988.,p. B-118]**PEER REVIEWED**

Other Chemical/Physical Properties:

Deliquescent
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 915]**PEER REVIEWED**

Approximate Amount of Substance Absorbed by 1 g Charcoal: 35 mg.
[Arena, J. M. Poisoning: Toxicology, Symptoms, Treatments. Fourth Edition. Springfield, Illinois: Charles C. Thomas, Publisher, 1979. 50]**PEER REVIEWED**

Specific heat: 1.01 J/g @ 25-72 deg C; heat of fusion: 14.7X10+3 J/mole; heat of formation: -113X10+3 J/mole (exothermic); heat of soln: 11.7X10-3 J/mole; hydrolysis constant: 2.54X10-5 @ 25 deg C
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 775]**PEER REVIEWED**

Kh= 2.54x10-5, hydrolysis to hydrogen cyanide.
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.39 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Chemical Safety & Handling:

DOT Emergency Guidelines:

Health: TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns, or death. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat which will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

Fire or explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases. Reaction with water may generate much heat which will increase the concentration of fumes in the air. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or contaminated with water.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

Public safety: CALL Emergency Response Telephone Number. ... Isolate spill or leak area immediately for at least 50 to 100 meters (160 to 330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

Protective clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing which is specifically recommended by the manufacturer. Structural firefighters' protective clothing is recommended for fire situations ONLY; it is not effective in spill situations.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

Evacuation: Spill: Fire: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

Fire: Note: Most foams will react with the material and release corrosive/toxic gases. Small fires: CO2 (except for Cyanides), dry chemical, dry sand, alcohol-resistant foam. Large fires: Water spray, fog or alcohol-resistant foam. Move containers from fire area if you can do it without risk. Do not use straight streams. Dike fire control water for later disposal; do not scatter the material. Fire involving tanks or car/trailer loads: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from the ends of tanks.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

Spill or leak: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. A vapor suppressing foam may be used to reduce vapors. DO NOT GET WATER INSIDE CONTAINERS. Use water spray to reduce vapors or divert vapor cloud drift. Prevent entry into waterways, sewers, basements or confined areas. Small spills: Cover with DRY earth, DRY sand, or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

First aid: Move victim to fresh air. Call emergency medical care. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved, and take precautions to protect themselves.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-157]**PEER REVIEWED**

List of Dangerous Water-Reactive Materials: Materials Which Create Large Amounts of Toxic (PIH) Vapor When Spilled in Water (Dangerous From 0.5 to 10 km (0.3 to 6.0 miles) Downwind) Name of Material: Potassium cyanide, Toxic Vapor (PIH) Produced: Hydrogen cyanide.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. TABLE]**PEER REVIEWED**

Fire Fighting Procedures:

Do not use carbon dioxide extinguisher. Extinguish fire using agent suitable for surrounding fire. Water may be used on nearby fires not involving potassium cyanide. Use water spray to keep fire-exposed containers cool. Use alkali dry chemical.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997. 109]**PEER REVIEWED**

Carbon dioxide fire extinguishers must not be used where cyanide salts are present. /Cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.24 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Use "alcohol" foam, dry chemical, or carbon dioxide. Use water spray to knock-down vapors. /Potassium cyanide solution/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use foam, dry chemical, or carbon dioxide. Do not use water on material itself. If large quantities of combustibles are involved, use water in flooding quantities as spray and fog. Use water spray to knock-down vapors. /Potassium cyandie, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Toxic Combustion Products:

When heated to decomp it emits very toxic fumes of cyanide & oxides of nitrogen.
[Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984. 2273]**PEER REVIEWED**

Hazardous Reactivities & Incompatibilities:

Reacts with water or any acid releasing hydrogen cyanide.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-109]**PEER REVIEWED**

INCOMPATIBILITIES: ACIDS & ACID SYRUPS, ALKALOIDS, CHLORAL HYDRATE, IODINE, METALLIC SALTS, PERMANGANATES, CHLORATES, PEROXIDES
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 1100]**PEER REVIEWED**

Chlorates plus potassium cyanide explode when heated.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-159]**PEER REVIEWED**

A mixture of /potassium cyanide and nitrites/ may cause an explosion.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-128]**PEER REVIEWED**

Nitrogen trichloride explodes on contact with ... potassium cyanide. ...
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 491-130]**PEER REVIEWED**

Hydrogen cyanide and mercury (II) cyanide: The cyanide, /mercury(II) cyanide/, is a friction- and impact-sensitive explosive and may initiate detonation of liquid hydrogen cyanide. Other metal cyanides are similar. /Cyanides/
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 316]**PEER REVIEWED**

Mixtures /of mercuric nitrate and potassium cyanide/ exploded when heated, but only if contained in narrow igintion tubes. Formation of nitrite, a more powerful oxidant than nitrate, may have been involved.
[Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990 1273]**PEER REVIEWED**

Perchloryl fluoride /& potassium cyanide/: Explosive reaction at 100-300 deg C.
[ITII. Toxic and Hazarous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1982. 686]**PEER REVIEWED**

... Reaction with ammoniacal silver /following/ heating, shock, /or/ standing /can cause an/ explosion (formation of silver fulminate - self-explosive). ... Heating /of potassium cyanide &/ chromium tetraoxide /can cause an/ explosion.
[ITII. Toxic and Hazarous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1982. 429]**PEER REVIEWED**

Cyanide may react with carbon dioxide in ordinary air to form toxic hydrogen cyanide gas. /Cyanide/
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 3]**PEER REVIEWED**

Readily oxidized by heating to potassium cyanate in presence of oxygen or easily reduced oxides
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. 7(79) 328]**PEER REVIEWED**

Fusion of mixtures of metal cyanides with metal chlorates, perchlorates, or nitrates ... causes a violent explosion. /Metal cyanides/
[Bretherick, L. Handbook of Reactive Chemical Hazards. 3rd ed. Boston, MA: Butterworths, 1985. 1570]**PEER REVIEWED**

Contact with acids and acid salts causes immediate formation of toxic and flammable hydrogen cyanide gas. ... /Cyanides/
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 3]**PEER REVIEWED**

Strong oxidizers (such as acids, acid salts, chlorates & nitrates) [Note: Absorbs moisture from the air forming a syrup].
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 262]**PEER REVIEWED**

Hazardous Decomposition:

Potassium ... cyanide solutions give off hydrogen cyanide when heated above 176 deg F. /Potassium cyanide soln/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.52 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Toxic gases and vapors (such as hydrogen cyanide and carbon monoxide) may be released when cyanide decomposes. /Cyanide/
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 3]**PEER REVIEWED**

When heated to decomposition, it emits very toxic fumes of /dipotassium oxide, hydrogen cyanide, and nitrogen oxides/.
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 2758]**PEER REVIEWED**

Immediately Dangerous to Life or Health:

25 mg/cu m (as CN)
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 262]**PEER REVIEWED**

Protective Equipment & Clothing:

WHERE SKIN CAN BE EXPOSED ... PROTECTIVE CLOTHING INCL IMPERVIOUS HAND PROTECTION SHOULD BE PROVIDED. ... WORKERS ENTERING CONTAMINATED AREA MUST WEAR IMPERVIOUS PROTECTIVE CLOTHING AS WELL AS ... RESPIRATORY PROTECTIVE EQUIPMENT. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 576]**PEER REVIEWED**

Respirator Selection: Less than or equal to 25 mg/cu m: (1) Filter type respirators, approved for toxic dust, with half-mask (not applicable for calcium cyanide). (2) Chemical cartridge respirators with replaceable cartridge for toxic dusts and acid gases; With half-mask. Maximum service life 4 hr. Less than or equal to 50 mg/cu m: (1) Full-face gas mask, chest or back mounted type, with industrial size canister for toxic dust and hydrocyanic acid gas. Maximum service life 2 hr. (2) Type C supplied air-respirator, continuous-flow or pressure-demand type (positive pressure) with full facepiece. (3) Type A supplied-air respirator, (hose mask with blower) with full facepiece. Greater than 50 mg/cu m: (1) Self-contained breathing apparatus with positive pressure in full facepiece. (2) Combination supplied-air respirator pressure-demand type with auxiliary self-contained air supply. Emergency (no concentration limit): (1) Self-contained breathing apparatus with positive pressure in facepiece. (2) Combination supplied-air respirator, pressure-demand type, with auxiliary self-contained air supply. Evacuation or Escape (no concentration limit): (1) Self-contained breathing apparatus in demand or pressure-demand mode (negative or positive pressure). (2) Full-face gas mask, front or back mount type with industrial size canister for toxic dust and hydrocyanic acid gas. /Cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.14 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Chemical safety goggles shall be worn by employees engaged in any operation wherein there is danger or likelihood that dusts or solutions of cyanide salts will come into contact with the eye. Full-length face shields with forehead protection shall be worn by employees engaged in any operation wherein there is danger or likelihood that dusts, molten salts, or solutions of cyanide salts may contact the face. /Cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.17 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Wear ... rubber gloves ... overalls and aprons.
[ITII. Toxic and Hazarous Industrial Chemicals Safety Manual. Tokyo, Japan: The International Technical Information Institute, 1982. 4429]**PEER REVIEWED**

Wear appropriate personal protective clothing to prevent skin contact.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Wear appropriate eye protection to prevent eye contact.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.]
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Recommendations for respirator selection. Max concn for use: 25 mg/cu m. Respirator Class(es): Any supplied-air respirator. Any self-contained breathing apparatus with a full facepiece.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Recommendations for respirator selection. Condition: Emergency or planned entry into unknown concn or IDLH conditions: Respirator Class(es): Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive pressure mode. Any supplied-air respirator that has a full facepiece and is operated in pressure-demand or other positive pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive pressure mode.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Recommendations for respirator selection. Condition: Escape from suddenly occurring respiratory hazards: Respirator Class(es): Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister /SRP: rebreather or oxygen generating/ providing protection against the compound of concern and having a high-efficiency particulate filter. Any appropriate escape-type, self-contained breathing apparatus.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Preventive Measures:

... ATTENTION TO ... VENTILATION IS NECESSARY. ... BECAUSE OF LOW PERMISSIBLE EXPOSURE LEVEL FOR HYDROGEN CYANIDE, COMPLETE ENCLOSURE OF PROCESS IS RECOMMENDED. ... WHERE AN EXPOSURE EXISTS, WORKERS SHOULD BE TRAINED TO RECOGNIZE THE ODOR ... & WHEN THIS IS DETECTED, THE WORK AREA SHOULD BE EVACUATED IMMEDIATELY. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 576]**PEER REVIEWED**

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.
**PEER REVIEWED**

Eyewash facilities and emergency showers shall be provided in areas where contact with ... cyanide salts as either solids or solutions is likely. Work clothing which has been contaminated by absorption of, or contact with, cyanide shall be thoroughly laundered before it is worn again. /Hydrogen cyanide and cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.31 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

If the clothing is to be laundered or otherwise cleaned to remove the cyanide, the person performing the operation should be informed of cyanide's hazardous properties. /Cyanides/
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 3]**PEER REVIEWED**

Two physician's treatment kits shall be immediately available to trained medical personnel at each plant where there is a potential for the release of, accidental or otherwise, or for contact with, hydrogen cyanide or cyanide salts. ... First-aid kits shall be immediately available at workplaces where there is potential for the release, accidental or otherwise, of hydrogen cyanide or a potential for exposure to cyanide salts. ... Pertinent medical records shall be maintained ... /SRP: for the duraton of employment plus 50 years [29 CFR 1910.1020]/ following the last exposure to hydrogen cyanide or cyanide salts. /Hydrogen cyanide and cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.3-4 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

PERSONS WHO WORK WITH & AROUND CYANIDE PREPN SHOULD BE GIVEN SPECIFIC DETAILED INSTRUCTIONS ON MANAGEMENT OF CYANIDE POISONING. /CYANIDES/
[Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975. 905]**PEER REVIEWED**

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers.
**PEER REVIEWED**

Food storage, preparation, and eating shall be prohibited in areas where hydrogen cyanide is used. Smoking and the carrying of tobacco and other smoking materials shall also be prohibited in these areas. Clean and sanitary lunchroom facilities, if provided, must be in non-exposure areas. ... Clothing-change and locker-room facilities shall be provided in a non-exposure area. Workers should be encouraged to shower after work and to change work clothing frequently. Showers and basin washing facilities shall be located in the locker-room area. /Hydrogen cyanide or cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.31 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

The worker should immediately wash the skin when it becomes contaminated.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Work clothing that becomes wet or significantly contaminated should be removed and replaced.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

ALL CONTAINERS ... SHOULD BE KEPT COVERED OR IN EXHAUSTED HOOD WHEN NOT IN USE. ANY PROCESS THAT MAY RELEASE HYDROGEN CYANIDE SHOULD BE MECHANICALLY EXHAUSTED, WITH PROVISION FOR HIGHER RATE DURING EMERGENCIES. DIRECT READING INSTRUMENTS FOR DETERMINATION OF HYDROCYANIC ACID ARE AVAILABLE. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 576]**PEER REVIEWED**

Contact lenses should not be worn when working with this chemical.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 263]**PEER REVIEWED**

If material not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. /Potassium cyanide solution/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

If material not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Use water spray to knock-down vapors. Do not use water on material itself. /Potassium cyanide, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Personnel protection: ... If contact with the material anticipated, wear appropriate chemical protective clothing. /Potassium cyanide, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Personnel protection: Avoid breathing vapors. Keep upwind. ... Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. /Potassium cyanide solution; potassium cyanide, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Stability/Shelf Life:

In air, it is gradually decomp on exposure to carbon dioxide and moisture.
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 1100]**PEER REVIEWED**

Shipment Methods and Regulations:

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./
[49 CFR 171.2 (7/1/99)]**PEER REVIEWED**

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.
[IATA. Dangerous Goods Regulations. 40th Ed. Montreal, Canada and Geneva, Switzerland: International Air Transport Association, Dangerous Goods Regulations, 1999. 197]**PEER REVIEWED**

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.
[IMDG; International Maritime Dangerous Goods Code; International Maritime Organization p.6241 (1998)]**PEER REVIEWED**

Storage Conditions:

PROTECT FROM LIGHT.
[The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983. 1100]**PEER REVIEWED**

ALL CONTAINERS OF CYANIDE SALTS SHOULD BE KEPT COVERED OR IN EXHAUST HOOD WHEN NOT IN USE. /CYANIDES/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 576]**PEER REVIEWED**

Store in a cool, dry, well-ventilated location. Separate from water, acids, and carbon dioxide. Outside or detached storage in preferred.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-110]**PEER REVIEWED**

Cyanide salts as solids must be stored in sealed or tightly closed containers. No hooks should be used in handling cyanide containers. ... Storage areas must be adequately ventilated to ensure that cyanide concentrations do not exceed the recommended workplace environmental limits. /Cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.24 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Cyanide salts as solids or solutions must be ... protected from corrosion or damage. They should be stored so there is no contact with nitrate-nitrite mixtures or peroxides. /cyanide salts/
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. 7(79) 326]**PEER REVIEWED**

... SHOULD BE STORED IN COOL, WELL-VENTILATED PLACE, OUT OF DIRECT RAYS OF SUN, AWAY FROM ... FIRE HAZARD, & SHOULD BE PERIODICALLY INSPECTED & MONITORED. INCOMPATIBLE MATERIALS SHOULD BE ISOLATED ... /CYANIDES & COPPER CMPD/
[Sax, N.I. Dangerous Properties of Industrial Materials. 4th ed. New York: Van Nostrand Reinhold, 1975. 262]**PEER REVIEWED**

Cleanup Methods:

Spills of cyanide salts should be immediately and carefully cleaned up by shoveling the material into a proper container. Care must be exercised to minimize any dispersal of cyanide dust into the air. /Cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.26-27 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

WASTE CYANIDE SALTS FROM CASE HARDENING OF STEEL ARE DESTROYED BY REACTING THE SALTS AT 650-700 DEG C WITH WASTE FERRIC HYDROXIDE SLUDGES FROM VARIOUS SOURCES. /CYANIDE SALTS/
[OEHLER B; TECH UMWELTSCHUTZ 24 (ABPRODUKTNUTZUNG): 133-9 (1980)]**PEER REVIEWED**

REMOVAL OF COPPER, NICKEL, ZINC, CADMIUM AND CYANIDE FROM PLATING WASTEWATER BY ELECTROFLOTATION. /CYANIDES/
[POON CP C; MANAGE CONTROL HEAVY MET ENVIRON, INT CONF 572-5 (1979)]**PEER REVIEWED**

Keep water away from release. Flush spill area with hypochlorite solution. Cover in noncombustible material for proper disposal. Shovel into suitable dry container. Control runoff and isolate discharged material for proper disposal.
[Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997.,p. 49-109]**PEER REVIEWED**

Environmental considerations - Land spill: Dig a pit, pond, lagoon, or holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. /Potassium cyanide, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Environmental considerations - Land spill: Dig a pit, pond, lagoon, or holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. /Potassium cyanide solution/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Environmental considerations - Air spill: Apply water spray or mist to knock down vapors. Vapor knock down water is corrosive or toxic and should be diked for containment. /Potassium cyanide solution; potassium cyanide, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Environmental considerations - Water spill: Add dilute caustic soda (sodium hydroxide). Add calcium hypochlorite ... Adjust pH to neutral (pH= 7). /Potassium cyanide solution; potassium cyanide, solid/
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 897]**PEER REVIEWED**

Disposal Methods:

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P098; D003, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
[40 CFR 240-280, 300-306, 702-799 (7/1/96)]**PEER REVIEWED**

Cyanide salts should not be flushed into any drain which may contain or subsequently receive acid waste. ... Cyanide process waste solutions and flushings from spills should be passed through a cyanide waste disposal system. /Cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.27 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Potassium cyanide is a poor candidate for incineration.
[USEPA; Engineering Handbook for Hazardous Waste Incineration p.3-10 (1981) EPA 68-03-3025]**PEER REVIEWED**

Occupational Exposure Standards:

 

OSHA Standards:

Permissible Exposure Limit: Table Z-1 8-hr Time-Weighted Avg: 5 mg/cu m. Skin Designation. /Cyanides, as CN/
[29 CFR 1910.1000 (7/1/99)]**PEER REVIEWED**

Threshold Limit Values:

Ceiling limit 5 mg/cu m, skin
[American Conference of Governmental Industrial Hygienists. Threshold Limit Values (TLVs) for Chemical Substances and Physical Agents Biological Exposure Indices for 1999. Cincinnati, OH: ACGIH, 1999. 42]**PEER REVIEWED**

NIOSH Recommendations:

Recommended Exposure Limit: 10 Min Ceiling value: 5 mg/cu m (4.7 ppm).
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 262]**PEER REVIEWED**

Immediately Dangerous to Life or Health:

25 mg/cu m (as CN)
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 262]**PEER REVIEWED**

Other Occupational Permissible Levels:

Inorganic cyanide standards: Bulgaria 0.3 mg/cu m Czechoslovakia 3-15 mg/cu m, Finland 7 mg/cu m, Federal Republic of Germany 5 mg/cu m, Hungary 0.3 mg/cu m, Poland 0.3 mg/cu m, Romania 0.3 mg/cu m, USSR 0.3 mg/cu m, Yugoslavia 5 mg/cu m. /Calcium, potassium, sodium, cyanide salts/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.190 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Manufacturing/Use Information:

Major Uses:

PC Code(s): 599600, 0 labels match
[California Environmental Protection Agency; Dept Pest Reg. USEPA/OPP Chemical Ingredients Database. Available from http://www.cdpr.ca.gov/cgi-bin/epa/mkepa3.pl?chems=599600&activeonly=on for potassium cyanide (151-50-8) as of May, 2000]**PEER REVIEWED**

ELECTROPLATING, STEEL HARDENING, EXTRACTION OF GOLD & SILVER FROM ORES; FUMIGATION OF FRUIT TREES, SHIPS, RAILWAY CARS, WAREHOUSES
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 575]**PEER REVIEWED**

Reagent in analytical chemistry, in insecticide, extraction of gold and silver from ores.
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 915]**PEER REVIEWED**

Primarily for silver plating and also for dyes & specialty products; with sodium cyanide for nitriding steel
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. 7 774]**PEER REVIEWED**

Manufacturers:

Du Pont de Nemours & Co., Inc, Hq, 1007 Market St., Wilmington, DE 19898, (302) 774-1000; Chemicals and Pigments Department; Production site: Memphis, TN 38127
[SRI. 1999 Directory of Chemical Producers - United States. Menlo Park, CA. SRI Consulting 1999. 852]**PEER REVIEWED**

Eagle-Picher Industries, Inc., 250 East 5th St., Suite 500, Cincinnati, OH 45202, (513)721-7010; Production site: Lenexa, KS 66215
[SRI. 1999 Directory of Chemical Producers - United States. Menlo Park, CA. SRI Consulting 1999. 852]**PEER REVIEWED**

Hampshire Chemical Corp., 55 Hayden Ave., Lexington, MA 02173, (781)861-9700; Production site: Nashua, NH 03060.
[SRI. 1999 Directory of Chemical Producers - United States. Menlo Park, CA. SRI Consulting 1999. 852]**PEER REVIEWED**

Methods of Manufacturing:

Manufactured by the reaction of an aqueous solution of potassium hydroxide with hydrogen cyanide.
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V7 (79) 329]**PEER REVIEWED**

Formulations/Preparations:

Grades: Commercial; Pure; Solution; Reagent
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 915]**PEER REVIEWED**

The article of commerce contains about 95% KCN.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

M-44 capsules (Potassium cyanide); Pelleted/tabletted; 89.0% potassium cyanide (599600)
[Purdue University; National Pesticide Information Retrieval System (1987)]**PEER REVIEWED**

To prepare 99.5% /use/ high quality potassium cyanide and potassium hydroxide.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

Commercial potassium cyanide made by neutralization or wet process ... contains 99% potassium cyanide.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

Impurities:

The principal impurities are potassium carbonate, formate, and hydroxide.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

U. S. Imports:

(1984) 1.87X10+8 g
[BUREAU OF THE CENSUS, US IMPORTS FOR CONSUMPTION AND GENERAL IMPORTS 1984 p.1-349]**PEER REVIEWED**

(1986) 1.47X10+6 lb
[BUREAU OF THE CENSUS. US IMPORTS FOR CONSUMPTION AND GENERAL IMPORTS 1986 P.1-516]**PEER REVIEWED**

(1987) 1,468,423 lb
[BUREAU OF THE CENSUS. US IMPORTS FOR CONSUMPTION AND GENERAL IMPORTS 1987 P.1-516]**PEER REVIEWED**

U. S. Exports:

(1984) 1.25X10+8 g
[BUREAU OF THE CENSUS, US EXPORTS, SCHEDULE E, 1984 p.2-92]**PEER REVIEWED**

(1987) 32,145 lb
[BUREAU OF THE CENSUS. U.S. EXPORTS, SCHEDULE E, AUGUST 1987, p. 9-82]**PEER REVIEWED**

Laboratory Methods:

Clinical Laboratory Methods:

A FLUOROMETRIC MICRODIFFUSION METHOD IS DESCRIBED FOR DETERMINING CYANIDE IN BIOLOGICAL FLUIDS. THIS DETECTION IS BASED ON THE PRODUCTION OF FLUORESCENCE BY THE TREATMENT OF CN WITH P-BENZOQUINONE DERIVATIVES. /TOTAL CYANIDE/
[MORGAN R ET AL; PROC WEST PHARMACOL SOC 19: 392-96 (1976)]**PEER REVIEWED**

CYANIDE MAY BE LIBERATED FROM BIOLOGICAL FLUIDS /BLOOD, URINE/ BY ACIDIFICATION. THE EVOLVED CYANIDE IS ABSORBED IN ALKALI AND SODIUM CYANIDE THUS FORMED IS QUANTITATIVELY DETERMINED BY MEASURING THE ABSORBANCE OF CHROMOPHORES FORMED BY INTERACTION OF THE CYANIDE ION WITH SUITABLE REAGENTS ... /ANOTHER/ PROCEDURE PRESENTS A SENISITIVE GAS CHROMATOGRAPHIC METHOD FOR DETERMINATION OF CYANIDE IN BIOLOGICAL SPECIMENS, BASED ON ITS CONVERSION TO CYANOGEN CHLORIDE USING CHLORAMINE-T. /TOTAL CYANIDE/
[Sunshine, Irving (ed.) Methodology for Analytical Toxicology. Cleveland: CRC Press, Inc., 1975. 113]**PEER REVIEWED**

A sensitive and specific radiolabel method for measuring expired (hydrogen cyanide or carbon dioxide) derived from cyanide was developed. An ethyl alcohol collecting solution containing 10-2M cobalt chloride trapped 88% of the (14)hydrogen cyanide passed through the solution following acid volatilization of a known amount of (14)potassium cyanide. The range of linearity, r= 0.998, exceeded the 0.01-0.1 umoles tested for measuring the pulmonary metabolites. The cobalt chloride collecting solution trapped <0.02% of the 10-100 umoles of (14)carbon dioxide generated by acid hydrolysis of (14)sodium bicarbonate introduction of a 2nd collecting solution specific for carbon monoxide, composed of ethyl alcohol: ethanolamine (2:1), was used to collect the carbon monoxide derived from cyanide. Following the sc administration to mice of 4.6 mg/kg of potassium cyanide and 4.5 uCi (14)potassium cyanide 1.2% and 2.3% of the dose was expired as (14)hydrogen cyanide and (14)carbon dioxide, respectively. /Total cyanide/
[Johnson JD, Isom GE; J Anal Toxicol 9 (3): 112-15 (1985)]**PEER REVIEWED**

GAS CHROMATOGRAPHIC DETERMINATION OF CYANIDES IN BIOLOGICAL SPECIMENS BASED UPON ITS CONVERSION TO CYANOGEN CHLORIDE USING CHLORAMINE-T (SODIUM P-TOLUENE SULFONCHLORAMIDE IS DESCRIBED. /TOTAL CYANIDE/
[VALENTOUR ET AL; ANAL CHEM 46: 924 (1974)]**PEER REVIEWED**

Analytic Laboratory Methods:

/DETERMINATION/ OF SODIUM & POTASSIUM CYANIDES USING TITRIMETRIC METHOD. TITRATE WITH SILVER NITRATE.
[Association of Official Analytical Chemists. Official Methods of Analysis. 10th ed. and supplements. Washington, DC: Association of Official Analytical Chemists, 1965. New editions through13th ed. plus supplements, 1982.,p. 10/46 4.088]**PEER REVIEWED**

Seven methods for the analysis of simple cyanides have been investigated including: 1) An ion-exchange procedure; 2) A continuous flow distillation; 3) An EDTA electrode method; 4) The AISI aeration method; 5) An EDTA aeration method; 6) The modified Roberts-Jackson method; and 7) The EPA method for cyanides amenable to chlorination. Of all the seven procedures studied, the modified Roberts-Jackson method is the best. It gives complete recovery for all but one of the simple cyanides without decomposing the complex cyanides. ... It has the unique ability to perform accurately in the presence of both sulfide and thiocyanate. Incomplete recovery of cyanide is found only from the mercury cyanide compounds. The addition of chloride ion during analysis will probably overcome this deficiency. A lower limit of 2 ppb + or - 1 ppb is possible with a precision of + or - 10% above 10 ppb. ... The ligand-exchange procedure appears to be the most advantageous method of analysis of total cyanides. /Total cyanides/
[USEPA; Development and Evaluation of Procedures for the Analyis of Simple Cyanides, Total Cyanide, and Thiocyanate in Water and Wastewater p.1 (1983) EPA 600/S4-83-054]**PEER REVIEWED**

Color reaction: Oxidation of hemoglobin to methemoglobin, which reacts with cyanide to form cyanomethemoglobin. This compound has a characteristic red color and a characteristic absorption spectrum. /Total cyanide/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.97 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

Colorimetric method: Pyridine-pyrazolone. /Total cyanide/
[NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.98 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

EPA Method 9010: Total and Amenable Cyanide (Colorimetric, Manual) Method 9010 is used to determine the concentration of inorganic cyanide in an aqueous waste or leachate. The method detects inorganic cyanides that are present as either simple soluble salts or complex radicals. It is used to determine values for both total cyanide and cyanide amenable to chlorination; it is not intended to determine if a waste is hazardous by the characteristic of reactivity. The cyanide, as hydrocyanic acid, is released by refluxing the sample with strong acid and distillation of the hydrogen cyanide into an absorber-scrubber containing sodium hydroxide solution. The cyanide ion in the absorbing solution is then manually determined colorimetrically by converting the cyanide to cyanogen chloride by reaction with chloramine-T at a pH less than 8 without hydrolyzing the cyanate. ... Color is formed on addition of the pyridine-barbituric acid reagent. In a single laboratory, using mixed domestic and industrial waste samples at concentrations of 0.06, 0.13, 0.28, and 0.62 mg CN/l, the standard deviations were + or - 0.005, + or - 0.007, + or - 0.031, and + or - 0.094, respectively. In a single laboratory, using mixed industrial and domestic waste samples at concentrations of 0.28 and 0.62 mg CN/l, recoveries were 85% and 102%, respectively. /Total and Amenable Cyanide/
[USEPA; Test Methods for Evaluating Solid Waste SW-846 (1986)]**PEER REVIEWED**

Indirect atomic absorption spectrometric analysis: (1) The complex dicyano-bis-(1,10-phenanthroline)-iron (II) is formed and then extracted into chloroform. The chloroform is evaporated and the residue is taken up in ethanol. The ethanol solution is aspirated directly into the flame, and iron equivalent to a known amount of cyanide is then determined. (2) The second method is based on precipitating silver cyanide, then determining the excess silver ion in the supernatant by atomic absorption spectrometry. /Total Cyanide/
[Danchik RS, Botz DF; Anal Chim Acta 49: 567-69 (1970) as cited in NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts p.99 (1976) DHEW Pub. NIOSH 77-108]**PEER REVIEWED**

REVIEW WHICH DISCUSSES THE METHODS & LIMIT OF DETECTIONS OF CYANIDE IN NATURAL & TREATED WATERS, INDUST EFFLUENTS, BIOLOGIC FLUIDS & SOLIDS: GAS CHROMATOGRAPHY (25 NG/ML), FLUOROMETRY (1 PPB), ION-SELECTIVE ELECTRODES (25 UG/L) & ABSORPTION SPECTROPHOTOMETRY (1-5 UG/L). /TOTAL CYANIDE/
[USEPA; REVIEWS OF ENVIRONMENTAL EFFECTS OF POLLUTANTS: V. CYANIDE P.28 (1978) EPA-600/1-78-027]**PEER REVIEWED**

Sampling Procedures:

AIR SAMPLES ARE USUALLY COLLECTED ON FILTERS.
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 1886]**PEER REVIEWED**

Special References:

Special Reports:

NIOSH; Criteria Document: Hydrogen Cyanide and Cyanide Salts (1976) DHEW Pub. NIOSH 77-108

USEPA/ODW; Health Advisory for: Potassium Cyanide (Draft) (1985)

Nat'l Research Council Canada; Effects of Cyanides on Aquatic Organisms with Emphasis Upon Fresh Water Fishes (1982) NRCC No.19246

DHHS/ATSDR; Toxicological Profile for Cyanide (Update) TP-92/09 (1993)

REVIEWS OF ENVIRONMENTAL EFFECTS OF POLLUTANTS: V. CYANIDE, ORNL/EIS-81, EPA-600/1-78-027, OCTOBER 1978

USEPA; Ambient Water Quality Criteria Doc: Cyanide (1984) EPA 440/5-84-028

Synonyms and Identifiers:

Synonyms:

AI3-28749
**PEER REVIEWED**

Caswell No 688A
**PEER REVIEWED**

CYANIDE OF POTASSIUM
**PEER REVIEWED**

CYANURE DE POTASSIUM (FRENCH)
**PEER REVIEWED**

EPA Pesticide Chemical Code 599600
**PEER REVIEWED**

HYDROCYANIC ACID, POTASSIUM SALT
**PEER REVIEWED**

Kalium cyanid (German)
**PEER REVIEWED**

M-44 capsules (Potassium cyanide)
**PEER REVIEWED**

POTASSIUM CYANIDE (K(CN))
**PEER REVIEWED**

Associated Chemicals:

Cyanide ion;57-12-5

Formulations/Preparations:

Grades: Commercial; Pure; Solution; Reagent
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 915]**PEER REVIEWED**

The article of commerce contains about 95% KCN.
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996. 1314]**PEER REVIEWED**

M-44 capsules (Potassium cyanide); Pelleted/tabletted; 89.0% potassium cyanide (599600)
[Purdue University; National Pesticide Information Retrieval System (1987)]**PEER REVIEWED**

To prepare 99.5% /use/ high quality potassium cyanide and potassium hydroxide.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

Commercial potassium cyanide made by neutralization or wet process ... contains 99% potassium cyanide.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V7 774]**PEER REVIEWED**

Shipping Name/ Number DOT/UN/NA/IMO:

UN 1680; Potassium cyanide soln; potassium cyanide, solid

IMO 6.1; Potsssium cyanide

Standard Transportation Number:

49 232 26; Potassium cyanide, solid

49 232 25; Potassium cyanide, solution

 

EPA Hazardous Waste Number:

P098; An acute hazardous waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate.

D003; /SRP:/ A waste containing potassium cyanide may (or may not) be characterized a hazardous waste following testing for the reactivity characteristics as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations.

RTECS Number:

NIOSH/TS8750000

Administrative Information:

Hazardous Substances Databank Number: 1245
Last Revision Date: 20020114
Last Review Date: Reviewed by SRP on 5/6/2000

Great Lakes Chemical Corporation and the Pathfinders Camp