Information Regarding 2-Butanone and Solvent

http://toxnet.nlm.nih.gov/cgi-bin/sis/search
METHYL ETHYL KETONE

Synonym: 2 butanone
78-93-3

http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~c6N05d:1
Absorption, Distribution & Excretion :

Relatively little of absorbed MEK is excreted unchanged via the kidneys; a study of occupationally exposed workers revealed that it is less than 0.1% of the alveolar uptake ... In a similar study of workers occupationally exposed to a mixture of solvents, the excretion of MEK and a major recognizable metabolite, 3-hydroxy-2-butanone, was 0.1% of alveolar uptake ... The concentrations of both MEK and 3-hydroxy-2-butanone in urine were significantly correlated with the environmental level of MEK. Other metabolites of MEK, 2-butanol or 2,3-butanediol ... identified in the serum of guinea pigs, were not detected in the urine of the exposed workers. ... however ... human excretion of 2,3-butanediol was individually variable but averaged 2% of the absorbed MEK. The urinary excretion of 2-butanol, a minor metabolite of MEK was examined ... clearance of 2-butanol admin by gavage in rabbits was about 14% of the admin dose and in the form of a glucuronide.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.55 (1993)]**PEER REVIEWED**

Synonyms :

AETHYLMETHYLKETON (GERMAN)
**PEER REVIEWED**

Synonyms :

ETHYLMETHYLKETON (DUTCH)
**PEER REVIEWED**

Synonyms :

METILETILCHETONE (ITALIAN)
**PEER REVIEWED**

Synonyms :

METYLOETYLOKETON (POLISH)
**PEER REVIEWED**

Biological Half-Life :

Both animal and human data indicate a rapid turnover of MEK. In guinea-pigs receiving an ip dose of 450 mg MEK/kg, the half-life of MEK in blood serum was 4.5 hr and the clearance time for MEK in serum was 12 hr. For the metabolites 2-butanol, 3-hydroxy-2-butanone and 2,3-butanediol, the clearance time in serum was 11 hr ... In a study ... on rats given an oral dose of 2-butanone of 2.1 mg/kg, there was a half-life of 3.6 hr for MEK in blood if the rate of loss was assumed to be constant between the two times of measurement (4 and 18 hrs) after dosing. Data from a study ... on rats receiving oral doses of 2-butanol or MEK also indicate a half-life of about 4 hr for MEK. ... the clearance rate for 3-hydroxy-2-butanone and 2,3-butanediol was independent of dose for the two doses used (0.4 and 0.8 g/kg) and that the half-lives for these metabolites of MEK were 47 min and 3.45 hr, respectively.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.56 (1993)]**PEER REVIEWED**

Consumption Patterns :

SOLVENT FOR VINYL COATINGS, 30%; SOLVENT FOR ADHESIVES, 18%; SOLVENT FOR NITROCELLULOSE COATINGS, 13%; SOLVENT FOR ACRYLIC COATINGS, 11%; SOLVENT FOR OTHER COATINGS, 7%; SOLVENT FOR MAGNETIC TAPES, 7%; EXTRACTION SOLVENT FOR LUBE OIL DEWAXING, 5%; SOLVENT FOR PRINTING INKS, 5%; OTHER, 4% (1981)
[SRI]**PEER REVIEWED**

Human Toxicity Excerpts :

Toxic effects of common organic solvents on workers /were/ examined. The most notable acute effects of occupational exposure to organic solvents are /CNS depression/ and other nerve dysfunctions. The common symptoms of short term exposure are fatigue, headache, nausea, sleep disturbance, and alteration in memory. Psychomotor performance of adverse effects on intellectual or memory functions are demonstrated with psychological test batteries after long-term occupational exposure to organic solvents. The mutagenic, carcinogenic, and toxicological effects of ... methyl ethyl ketone ... are summarized. ... In clinical observations, the effects of organic solvents can cause increased excretion of abnormal cells and protein in urine. This indicates the possible correlation between long-term exposure and renal disease.
[Bang KM; Health Hazards in the Occupational Environment 7 (3): 15-29 (1984)]**PEER REVIEWED**

Human Toxicity Excerpts :

To determine whether unchanged solvent urinary concentration could be used as a biological exposure index, workers occupationally exposed to various solvents were studied. Nine unrelated groups (a total of 659 males) working in plastic boat, chemical, plastic button, paint, and shoe factories were studied. Urine samples were collected at the beginning of the workshift and at the end of the first half of the shift. A close relationship (correlation coefficient always above 0.85) between the average environmental solvent concentration (mg/cu m) measured in the breathing zone and the urinary concentration of unchanged solvent (ug/l) was observed.
[Ghittori S et al; Am Ind Hyg Assoc J 48 (9): 786-90 (1987)]**PEER REVIEWED**

Atmospheric Concentrations :

The presence of solvents such as toluene, xylene, methyl ethyl ketone, and other similar products in the indoor air of an automobile body repair shop, an offset printing facility and the adjacent dwellings was monitored, and the individual exposure of the corresponding workers and residents was tested by biological monitoring of exhaled breath and by personal air sampling. The concentrations of solvents tested in the air of both sites surveyed were lower than prevailing Dutch Maximum Allowable Concentration levels. The levels of solvents recorded in the air of apartments situated on top of the facilities surveyed were significantly higher than the levels recorded in the surrounding dwellings. The levels of methyl ethyl ketone, toluene and xylene in personal air samples of employees at the body shop were 1.5 times higher than in ambient air. The level of toluene in alveolar air of residents living above the automobile repair shop was 50 percent higher than that recorded in spot samples. The levels of other solvents were equal to or lower than the detection level. At the offset printing facility, toluene, xylene, butylacetate, 2-ethoxyethanol and cyclohexanone in air and in personal air samples followed the same general pattern identified for the body shop. In a dwelling next to the shop and in an apartment on top of the shop, the concentrations ranged from 3 to 9 percent and 14 to 19 percent, respectively, of the levels recorded inside the facility itself.
[Verhoeff AP et al; Int Arch Occup Environ Health 59 (2): 153-63 (1987)]**PEER REVIEWED**

Synonyms :

2-BUTANONE
**PEER REVIEWED**

Non-Human Toxicity Excerpts :

ANALYSIS OF PORPHYRIN CONTENT OF MURINE ERYTHROLEUKEMIA (MEL) CELLS INCUBATED WITH 2-BUTANONE SHOWED THAT INCR HEMOGLOBIN SYNTH WAS ACCOMPANIED BY ACCUM OF PORPHYRINS.
[EBERT PS ET AL; CHEM BIOL INTERACT 36 (1): 61 (1981)]**PEER REVIEWED**

Metabolism/Metabolites :

GUINEA PIGS WERE GIVEN SINGLE 450 MG/KG IP DOSES OF METHYL ETHYL KETONE (MEK). MEK PRODUCED 2-BUTANOL, 3-HYDROXY-2-BUTANONE, & 2,3-BUTANEDIOL.
[DIVINCENZO GD ET AL; TOXICOL APPL PHARMACOL 36 (3): 511 (1976)]**PEER REVIEWED**

Metabolism/Metabolites :

Rats were given a single oral dose of methyl ethyl ketone (MEK). The blood concn of MEK and metabolites 4 hr after dosing were: MEK (94.1 mg/100 ml); 2-butanol (3.2 mg/100 ml); 3-hydroxy-2-butanol (2.4 mg/100 ml) and 2,3-butanediol (8.6 mg/100 ml). Blood concn of the parent compound and metabolites 18 hr after dosing with MEK were: MEK (6.2 mg/100 ml); 2-butanol (0.6 mg/100 ml); 3-hydroxy-2-butanone (1.4 mg/100 ml); and 2,3-butanediol (25.6 mg/100 ml).
[Dietz FKJ, Traiger GJ; Toxicology 14: 209-14 (1979)]**PEER REVIEWED**

Metabolism/Metabolites :

... the toxic effects of MEK and 2-butanol were essentially identical in rats, and that 2-butanol was rapidly oxidized to MEK. ... identified the metabolites of MEK in guinea pigs as 2-butanol, 3-hydroxy-2-butanone and 2,3-butanediol. They hypothesized that the metabolism followed both oxidative and reductive pathways, with the latter leading to the production of 2-butanol.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.52 (1993)]**PEER REVIEWED**

RCRA Requirements :

U159; As stipulated in 40 CFR 261.33, when 2-butanone, 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 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).
[40 CFR 261.33 (7/1/96)]**PEER REVIEWED**

Sampling Procedures :

ANALYTE: 2-BUTANONE; MATRIX: AIR; RANGE: 380-1240 MG/CU M; PROCEDURE: ADSORPTION ON CHARCOAL, DESORPTION WITH CARBON DISULFIDE, GC.
[U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual of Analytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.V2 S3-1]**PEER REVIEWED**

Clinical Laboratory Methods :

A method is described for the determination of the concn of methyl ethyl ketone and its metabolites: 2-butanol, 3-hydroxy-2-butanone, and the meso- and d,l-isomers of 2,3-butanediol in urine. The analytes were isolated from urine by solid-phase extraction and analyzed by capillary gas chromatography. The recovery rates were 50-70% for the 2,3-butanediol isomers and 88-96% for the other analytes. The precision of the method ranged 5-12% (standard deviation %). The detection limit was 1.0 and 1.4 mg/l for meso- and d,l 2,3-butanediol, respectively, and ranged 0.1-0.15 mg/l for the other analytes.
[Kezic S, Monster AC; J Chromatogr 428 (2): 275-80 (1988)]**PEER REVIEWED**

Special Reports :

DHHS/ATSDR; Toxicological Profile for 2-Butanone (1992) ATSDR/TP-91/08

Preventive Measures :

A major concern in the painting studio is solvents, /including methyl ethyl ketone/. ... Precautions include ... use of dilution and local exhaust ventilation, control of storage areas, disposal of solvent soaked rags in covered containers, minimizing skin exposure and the use of respirators and other personal protective equipment. The control of fire hazards is also important, since many of the solvents are highly flammable.
[Hart C; J Environ Health 49 (5): 282-6 (1987)]**PEER REVIEWED**

Major Uses :

AS SOLVENT; IN THE SURFACE COATING INDUSTRY; MFR OF COLORLESS SYNTHETIC RESINS, SMOKELESS POWDER
[Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996.1037]**PEER REVIEWED**

Major Uses :

SOLVENT FOR COATINGS-ESP VINYL, NITROCELLULOSE & ACRYLIC
[SRI]**PEER REVIEWED**

Major Uses :

SOLVENT FOR ADHESIVES & MAGNETIC TAPES
[SRI]**PEER REVIEWED**

Major Uses :

EXTRACTION SOLVENT FOR LUBE OIL DEWAXING, AZEOTROPIC SEPN
[SRI]**PEER REVIEWED**

Major Uses :

SOLVENT FOR PRINTING INKS & IN CLEANING SOLNS
[SRI]**PEER REVIEWED**

Major Uses :

EXTRACTION SOLVENT FOR HARDWOOD PULPING & VEGETABLE OIL
[SRI]**PEER REVIEWED**

Major Uses :

SOLVENT & COSOLVENT IN PESTICIDE FORMULATIONS
[SRI]**PEER REVIEWED**

Major Uses :

... Solvent ... required for the polymerization processing of polystyrene, acrylonitrile-butadiene-styrene, and styrene-butadiene-rubber.
[Fishbein L; Industrial Hazards of Plastics and Synthetic Elastomers p.239-62 (1984)]**PEER REVIEWED**

Consumption Patterns :

CHEMICAL PROFILE: Methyl Ethyl Ketone. Coatings solvent, 50%; adhesives, 13%; magnetic tapes, 8%; lube oil dewaxing, 4%; printing inks, 3%; miscellaneous, 6%; exports, 16%.
[Kavaler AR; Chemical Marketing Reporter 232 (8): 50 (1987)]**PEER REVIEWED**

Disposal Methods :

The following wastewater treatment technologies have been investigated for methyl ethyl ketone: solvent extraction and activated carbon.
[USEPA; Management of Hazardous Waste Leachate, EPA Contract No.68-03-2766 p.E-16 (1982)]**PEER REVIEWED**

Disposal Methods :

Spray into incinerator or burn in paper packaging. More flammable solvent may be added.
[Prager, J.C. Environmental Contaminant Reference Databook Volume 1. New York, NY: Van Nostrand Reinhold, 1995.349]**PEER REVIEWED**

Human Toxicity Excerpts :

METHYL ETHYL KETONE IS IMPLICATED AS THE CAUSE OF RETROBULBAR NEURITIS IN PT WHO USED THE SOLVENT IN REMOVING PAINT FROM AN AIRPLANE HANGAR.
[BERG EF; ANN OPHTHALMOL 3 (12): 1351 (1971)]**PEER REVIEWED**

Human Toxicity Excerpts :

... Seventy healthy male and female volunteers, 18 to 32 years old, with no previous prolonged exposure to solvents were exposed to 0 or 250 ppm acetone, 200 ppm MEK, or 125 ppm acetone plus 100 ppm MEK vapors for 4 hours in an exposure chamber. Expired air samples were collected before exposure, after 2 and 4 hours exposure, 90 minutes after exposure ended, and the next morning. Blood samples were collected on the day preceding exposure, at 2 or 4 hours of exposure, 2 hours after exposure ended, and the following day. Samples were analyzed for acetone and MEK by gas or gas/liquid chromatography. ... Blood MEK or acetone concentrations continued to increase throughout exposure, the increases between 2 and 4 hours being larger in the case of acetone. Acetone concentrations in the breath took longer to decrease than those of MEK. No interactive effects were noted in the combined exposures. Blood acetone and MEK concentrations were moderately correlated with their breath concentrations. Blood MEK and acetone concentrations tended to be lower in female subjects than in males; however, the differences were significant only for acetone in the combination exposure after 2 hours exposure and 90 minutes postexposure. ...
[Brown WD et al; The Changing Nature of Work and Workforce, Proceedings of the Third Joint US-Finish Science Symposium p.111-14 (1986)]**PEER REVIEWED**

Human Toxicity Excerpts :

... exposure to 266-797 mg/cu m (90-270 ppm) for up to 4 hr/day caused his subjects to underestimate times of 5 to 30 sec ... on the other hand, found that a 4-hr exposure of human subjects to 590 mg/cu m (200 ppm) had no significant effect in a variety of behavioral test. These included psychomotor, visual vigilance, dual task, sensorimotor and psychological tests. Solvent mixtures of 295 mg MEK/cu m (100 ppm) and 298 mg acetone/cu m (125 ppm) similarly had no significant effect on the results of these behavioral tests.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.81 (1993)]**PEER REVIEWED**

Human Toxicity Excerpts :

Long-term exposure of 51 Italian workers to MEK produced indications of neurotoxicity with slightly, but not significantly, reduced nerve conduction velocities and various other symptoms such as headache, loss of appetite and weight, GI upset, dizziness, dermatitis and muscular hypotrophy, but no clinically recognizable neuropathy. ... There has been a brief report of chronic exposure of American workers, in a factory producing coated fabric, to 885-1770 mg MEK/cu m (300-600 ppm) in the apparent absence of other solvents. ... Workers complained of dermatoses and numbness of fingers and arms.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.82 (1993)]**PEER REVIEWED**

Human Toxicity Excerpts :

Two cases of acute poisoning in a raincoat manufacturing operation where the seams were waterproofed with a resin dissolved in either acetone or MEK were reported. Samples of the workroom air indicated that the MEK concentration ranged from 398 to 561 ppm, whereas the acetone concentration ranged from 330 to 495 ppm. Two female employees were reportedly affected by the solvent vapors on different occasions. The first complained of stomach distress and watery eyes one morning, and later was found unconscious in a rest room. The employee had a strong acetone odor on her breath, but no acetonuria upon admission to the local hospital. She was treated with a CNS stimulant and awoke immediately, but complained of a severe headache. The patient was discharged from the hospital on the day following admission. The second case followed the first one by 1 day and was apparently less severe. The individual fainted and convulsed at the work site but regained consciousness immediately afterwards. At the hospital she was confused and had a headache, but after 1 hr of observation she was allowed to return home.
[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., 1993-1994.1767]**PEER REVIEWED**

Human Toxicity Excerpts :

A case study where a male patient attempted suicide by ingesting approximately 100 ml of an adhesive cement that contained 39 percent cyclohexanone, 28% MEK, 18% acetone was presented. The individual reportedly drank about 720 ml of sake (10 percent ethanol) 30 min prior to drinking the adhesive solution. The patient was unconscious when taken to a hospital about 2 hr after the ingestion of the solvent mixture. Gastric lavage, plasma exchange, and charcoal hemoperfusion were all performed, and the patient regained consciousness about 7 hr after ingestion; however, signs of systemic toxicity persisted. High blood concentrations of a cyclohexanone metabolite (cyclohexanal) were thought to be responsible for the coma, whereas the hyperglycemia was attributed to acetone.
[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., 1993-1994.1767]**PEER REVIEWED**

Non-Human Toxicity Excerpts :

The effects of the solvents n-hexane, butanone (methyl ethyl ketone, MEK) and a mixture of both in the intrapulmonary nerve system of rats were studied by light and electron microscopy. The alteration in the fine structures of the tissues consisted in a disseminated swelling of axons due to a striking multiplication of neurofilaments. Nonspecific axonal alterations could be demonstrated as well. The latter consisted in clusters of phospholipid material within the axoplasm of nerve fibers and the cytoplasm of Schwann cells plus an accumulation of glycogen granules in the axoplasm. Additionally, single degenerative changes of Schwann cells were observed.
[Schmidt R; Respiration 46 (4): 62-9 (1984)]**PEER REVIEWED**

Non-Human Toxicity Excerpts :

Chinese hamsters were exposed to ... methyl ethyl ketone ... known to be a strong inducer of aneuploidy in the yeast Saccharomyces cerevisiae. ... Solvent yielded negative results in the micro-nucleus test.
[Basler A; Mutat Res 174 (1): 11-13 (1986)]**PEER REVIEWED**

Absorption, Distribution & Excretion :

The distribution of MEK in human tissues was examined ... in two solvent-exposed workers who died suddenly of heart attacks at the workplace. The results of this study ... indicate that the solubility of MEK is similar for all tissues. ... With a blood/air partition coefficient of 202, MEK can reach equilibrium concn in a compartment in about 3 min. Distribution volumes were 6.0 for vessel-rich tissues, 39.6 for muscle and 12.8 for fat. Biological half-lives for the same tissues were 0.8, 21.8 and 23.3 min, respectively.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.51 (1993)]**PEER REVIEWED**

Metabolism/Metabolites :

MEK has been identified as a minor but normal constituent of urine ... serum and urine of diabetics ... and expired air ... . Its production in the body has been attributed to isoleucine catabolism ... studies ... indicate that the same metabolites are produced and excreted in humans as in experimental animals. ... further indicated that in an inhalation exposure to 590 mg MEK/cu m (200 ppm) the calculated areas under the curves of blood solvent concn versus time (AUC) for MEK and 2,3-butanediol were equal, which suggests that MEK is almost completely transformed to 2,3-butanediol. The bulk of MEK absorbed thus enters the general metabolism and is transformed to simple compounds like carbon dioxide and water.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.55 (1993)]**PEER REVIEWED**

Biological Half-Life :

The distribution of MEK in human tissues was examined ... in two solvent-exposed workers who died suddenly of heart attacks at the workplace. ... Distribution volumes were 6.0 for vessel-rich tissues, 39.6 for muscle and 12.8 for fat. Biological half-lives for the same tissues were 0.8, 21.8 and 23.3 min, respectively.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.51 (1993)]**PEER REVIEWED**

Mechanism of Action :

The effects of the solvents n-hexane, butanone (methyl ethyl ketone, MEK) and a mixture of both in the intrapulmonary nerve system of rats were studied by light and electron microscopy. The alteration in the fine structures of the tissue consisted in a disseminated swelling of axons due to a striking multiplication of neurofilaments. Nonspecific axonal alterations could be demonstrated as well. The latter consisted in clusters of phospholipid material within the axoplasm of nerve fibers and the cytoplasm of Schwann cells plus an accumulation of glycogen granules in the axoplasm. Additionally, single degenerative changes of Schwann cells were observed. An enzyme associated metabolic damage with a concomitant impairment of axonal flow is discussed as a possible underlying pathomechanism.
[Schmidt R et al; Respiration 46 (4): 362-9 (1984)]**PEER REVIEWED**

Interactions :

The effects of acute exposure to toluene and methyl ethyl ketone (MEK) singly and in combination were investigated. ... The effects of these chemicals on behavior and body burden were determined. ... MEK had no effect on any measures. Behavior performance was not affected by the combination of toluene and MEK. Body burden of the two solvents was not additive. ... Neither chemical potentiated the effect of the other at the concentrations studied.
[Dick RB et al; Int Arch Occup Environ Health 54 (2): 91-109 (1984)]**PEER REVIEWED**

Interactions :

... An important observation was the marked potentiation of peripheral neurotoxicity observed when animals were exposed to n-butyl ketone in combination with methyl ethyl ketone at a ratio of 1:5, n-butyl ketone: methyl ethyl ketone. The latter solvent showed no neurotoxic effect alone.
[Saida K et al; J Neuropathol Exp Neurol 35 (3): 207-25 (1976)]**PEER REVIEWED**

Interactions :

... found that MEK and certain other polar aprotic solvents were strong inducers of aneuploidy in the yeast. The induction of aneuploidy by MEK was markedly potentiated by coexposure to ethyl acetate ... or with nocodazol ... .
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.80 (1993)]**PEER REVIEWED**

Interactions :

Carbon tetrachloride (CCl4), chloroform (CHCl3) and related haloalkane solvents are liver and kidney poisons as well as central nervous depressants ... It has long been known that the hepatotoxic action of CCl4 is potentiated by ethanol, and more recently that the hepatic and/or renal toxicity of CCl4, CHCl3, trichloroethylene, 1,1,2-trichloroethane and related compounds is potentiated by n-hexane, ethanol, isopropanol, acetone, MEK, MBK, 2,5-HD, and other ketones or chemicals that are metabolized to ketones ... Even an incr of naturally occurring ketones in the body via diabetes can precipitate potentiation. Decr the transformation of isopropanol to acetone by the admin of an inhibitor of alcohol dehydrogenase, pyrazole, has reduced potentiation of haloalkane toxicity. Although the phenomenon is referred to as haloalkane toxicity, experimental work in general appears largely or entirely limited to chlorinated compounds, and specific studies on MEK are limited to interactions with CCl4 and CHCl3.
[WHO; Environ Health Criteria 143: Methyl Ethyl Ketone p.115 (1993)]**PEER REVIEWED**

Environmental Fate/Exposure Summary :

Methyl ethyl ketone's production and use as a solvent for coatings, resins, rubbers, plastics, pharmaceuticals, adhesives and rubber cements will result in its release to the environment through various waste streams. Its use as a starting material or intermediate in the manufacture of chemical products will also lead to its release to the environment. Methyl ethyl ketone occurs naturally as a metabolic byproduct of plants and animals and is released into the atmosphere by volcanoes and forest fires. Based on an experimental vapor pressure of 91 mm Hg at 25 deg C, methyl ethyl ketone is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase methyl ethyl ketone is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals with an estimated atmospheric half-life of about 14 days. This compound is also expected to undergo photolysis in the atmosphere by natural sunlight. Photochemical degradation of methyl ethyl ketone by natural sunlight is expected to occur at approximately 1/5 the rate of degradation by photochemically produced hydroxy radicals. Methyl ethyl ketone is expected to have very high mobility in soils based upon measured Koc values of 29 and 34 obtained in silt loams. Volatilization from dry soil surfaces is expected based upon the vapor pressure of this compound. Volatilization from moist soil surfaces is also expected based upon the measured Henry's Law constant of 4.7X10-5 atm-cu m/mol. The volatilization half-life of methyl ethyl ketone from silt and sandy loams was measured as 4.9 days. This compound is expected to biodegrade under aerobic and anaerobic conditions. In water, methyl ethyl ketone is not expected to adsorb to suspended solids or sediment based upon its measured Koc values. Volatilization from water surfaces is expected to be an important environmental fate process given its Henry's Law constant. Estimated half-lives for a model river and model lake are 19 and 197 hours, respectively. Bioconcentration in aquatic organisms is considered low based upon an estimated BCF value of 1. Occupational exposure may be through inhalation and dermal contact with this compound at workplaces where methyl ethyl ketone is produced or used. The general population may be exposed to methyl ethyl ketone through the use of commercially available products containing this compound such as paints, adhesives, and rubber cements. Exposure will also arise from inhalation of ambient air and ingestion of drinking water and food that contains methyl ethyl ketone. (SRC)
**PEER REVIEWED**

Artificial Pollution Sources :

Methyl ethyl ketone's production and use as a solvent for coatings, resins, rubbers, plastics, pharmaceuticals, adhesives and rubber cements(1-3) will result in its release to the environment through various waste streams(SRC). Its use as a starting material or intermediate in the manufacture of chemical products(2,3) will also lead to its release to the environment(SRC).
[(1) Budvari S; Merck Index, 12th ed, Whitehouse Station,NJ: Merck & Co. p. 1773 (1996) (2) Browning E; Toxicity and Metabolism of Industrial Solvents. NY,NY: American Elsevier (1965) (3) Lewis RJ Sr ed; Hawley's Condensed Chemical Dictionary. 12th ed NY,NY: Van Nostrand Rheinhold Co p. 768 (1993)]**PEER REVIEWED**

Allowable Tolerances :

Methyl ethyl ketone is exempted from the requirement of a tolerance when used as a solvent, cosolvent in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only.
[40 CFR 180.1001(d) (7/1/96)]**PEER REVIEWED**

RCRA Requirements :

F005; When methyl ethyl ketone is a spent solvent, it is classified as a hazardous waste from a nonspecific source (F005), as stated in 40 CFR 261.31, and must be managed according to State and/or Federal hazardous waste regulations.
[40 CFR 261.31 (7/1/96)]**PEER REVIEWED**

FIFRA Requirements :

Methyl ethyl ketone is exempted from the requirement of a tolerance when used as a solvent, cosolvent in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only.
[40 CFR 180.1001(d) (7/1/96)]**PEER REVIEWED**

TSCA Test Submissions :

The ability of methyl ethyl ketone to induce morphological transformation in the BALB/3T3 mouse cell line (Cell Transformation Assay) was evaluated both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. Based on preliminary clonal toxicity determinations (exposure time=2 hrs), methyl ethyl ketone, diluted with phosphate buffered saline, was tested at 18, 13 and 9ul/ml in the absence of metabolic activation, with cell survival ranging from 93.3% to 51.1% relative to the solvent control. Assays with metabolic activation were tested at 10, 8 and 6ul/ml (exposure time=2 hrs), with cell survival ranging from 85.7% to 67.3%. None of the tested concentrations produced significantly greater transformation frequencies (p > 0.05, Modified Poisson Distribution) relative to the solvent control.
[Microbiological Associates Inc.; Activity of Methyl Ethyl Ketone in the Morphological Transformation Assay using BALB/3T3 Mouse Embryo Cells, Final Report, (1984), EPA Document No. 40-8444072, EPA Fiche No. OTS0507470]**UNREVIEWED**

TSCA Test Submissions :

The ability of methyl ethyl ketone to induce specific locus mutations at the TK locus in cultured L5178Y mouse lymphoma cells (Mouse Lymphoma Mutagenicity Assay) was evaluated in the presence and absence of Aroclor-induced rat liver S9 metabolic activation. Based on preliminary toxicity tests, 10 nonactivated cultures treated with 12, 8.9, 6.7, 5.0, 3.8, 2.8, 2.1, 1.6, 1.2 and 0.89ul/ml were cloned, producing a range of 46 - 122% total growth. Ten S9-activated cultures treated with 8.9, 6.7, 5.0, 3.8, 2.8, 2.1, 1.6, 1.2, 0.89 and 0.67ul/ml were cloned, producing a range of 30 - 116% total growth. None of the cultures that were cloned produced mutant frequencies which were significantly greater than the mean mutant frequency of the solvent controls (DMSO, acetone).
[Microbiological Associates Inc.; L5178Y TK +/- Mouse Lymphoma Mutagenicity Assay, Final Report, (1984), EPA Document No. 40-8444072, Fiche No. OTS0507470]**UNREVIEWED**

TSCA Test Submissions :

The effects of methyl ethyl ketone were examined in the rat hepatocyte primary culture/DNA repair assay. Based on preliminary toxicity tests, methyl ethyl ketone was tested at concentrations of 5.0 (relative toxicity 74.67%), 2.5, 1.0, 0.5, 0.1 or 0.01 ul/ml (relative toxicity 6.67%). None of the tested concentrations caused a significant increase in unscheduled DNA synthesis over the solvent control (DMSO).
[Microbiological Associates Inc.; Unscheduled DNA Synthesis in Rat Primary Hepatocytes, Final Report, (1984), EPA Document No. 40-8444072, Fiche No. OTS0507470]**UNREVIEWED**

GLCC RELATED TOXIC SUBSTANCES FOUND IN THE CAMP POND AND CAMP WATER WELL 2003 AND 2004

GREAT LAKES CHEMICAL CORPORATION AND THE PATHFINDERS CAMP