Information Regarding 2-Butanone and Adhesive
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METHYL
ETHYL KETONE
Synonym: 2 butanone
78-93-3
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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.
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.
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)
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.
Major Uses :
PAINT REMOVERS; CEMENTS & ADHESIVES;
ORG SYNTHESIS; IN CLEANING FLUIDS
Major Uses :
SOLVENT FOR ADHESIVES
& MAGNETIC TAPES
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)
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%.
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).
Probable Routes of Human Exposure :
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(SRC). Exposure will also arise from inhalation of ambient air,
ingestion of drinking water and food that contains methyl ethyl ketone(SRC). The
average blood concn of methyl ethyl ketone in 600 non-occupationally exposed
individuals in the US was 7.1 ppb(1).
FDA Requirements :
Methyl ethyl ketone is an indirect food
additive for use only as a component of adhesives.
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.
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.
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).
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.
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).
Sampling Procedures :
ANALYTE: 2-BUTANONE; MATRIX:
AIR; RANGE: 380-1240 MG/CU M; PROCEDURE: ADSORPTION ON CHARCOAL, DESORPTION WITH
CARBON DISULFIDE, GC.
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.
Special Reports :
DHHS/ATSDR; Toxicological Profile for 2-Butanone
(1992) ATSDR/TP-91/08
GLCC
RELATED TOXIC SUBSTANCES FOUND IN THE CAMP POND AND CAMP WATER WELL 2003 AND
2004