Spacecraft Water Exposure Guidelines for Selected Contaminants Volume 3 (2008) / Chapter Skim
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5 Methyl Ethyl Ketone
5 Methyl Ethyl Ketone
Pages 147-164
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From page 147... ...
for methyl ethyl ketone (MEK) vapors in spacecraft air in Volume 2 of the series Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants (Wong 1996)
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From page 148... ...
TOXICOKINETICS AND METABOLISM Most of the MEK toxicokinetic and metabolism data in the literature involve exposure by inhalation, but many of the toxicokinetic results should hold true for MEK exposures by ingestion as well. Absorption No quantitative data on the extent of absorption of ingested MEK in humans were identified, but case reports indicate that humans absorb enough MEK after ingestion of unknown quantities to cause systemic toxicity, including unconsciousness and metabolic acidosis (Kopelman and Kalfayan 1983)
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From page 149... ...
. Blood MEK concentrations increased rapidly during the first hour and then rose slowly and linearly until the end of the exposure.
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In rats and mice, exposure to MEK at 3,000 ppm for 7 h/d during gestation days 6-15 was a lowestobserved-adverse-effect level (LOAEL) for fetal toxicity, consisting of increased incidences of gross and skeletal anomalies and delayed sternebral ossification in rats and decreased fetal weight in mice (Deacon et al.
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. In similar tests of subclinical neurobehavioral performance, statistically significant effects were observed in only 4 of 32 measures in 68 male and 75 female volunteers exposed for 4 h to 200 ppm of MEK vapors, 100 ppm of methyl isobutyl ketone (MIBK)
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The authors concluded that the organ weight changes and altered serum enzyme values may indicate damage but also may be due to the development of an adaptive response, as no pathology was observed in routine histopathology studies (Cavender et al.
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. MEK had no effect in the Salmonella microsome assay, mouse lymphoma assay, BALB/3T3 mouse embryo cell transformation assay, unscheduled DNA synthesis in rat primary hepatocytes, and the in vivo mouse micronucleus assay (O'Donoghue et al.
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(1991) reported developmental toxicity (reduction in mean fetal body weight)
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. In a case report involving coingestion of unknown amounts of MEK and methanol that induced a hyperosmolar coma, the authors suggested that MEK may have inhibited methanol metabolism, contributing to the low observed serum formate concentration (1.3 mmol/L)
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F Unknown amount Case report Human, F, age Unconsciousness, hyperventilation, severe metabolic acidosis. Kopelman and ingested; serum: 950 47 Uneventful recovery.
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6-15 of mice toxicity. 1991 gestation 3,000-ppm inhalation 7 h/d, days Swiss CD-1 Developmental toxicity (low incidence of malformations)
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Environmental Protection Agency; IDLH, immediately dangerous to life and health; NIOSH, National Institute of Occupational Safety and Health; OSHA, Occupational Safety and Health Administration; PEL, permissible exposure limit; REL, recommended exposure limit; RfD, reference dose; STEL, short-term exposure limit; ST, short term; TLV, Threshold Limit Value; TWA, time-weighted average. Organoleptic Effects Although a concentration of 1,700 mg/L would be nontoxic, it has a definite odor.
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Garcia, unpub ppm lished material, 2007 SWEGs 540 54 54 54 Abbreviations: NA, not applicable; NOAEL, no-observed-adverse-effect level.
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in offspring of female rats exposed at an inhalation dose (about 3,000 ppm) that caused mild maternal toxicity (slightly decreased weight gain and increased maternal liver-to-body-weight ratio)
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1992. Neurobehavioral effects from acute exposures to methyl isobutyl ketone and methyl ethyl ketone.
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1989. Inhalation Developmental Toxicity Studies: Teratology Study of Methyl Ethyl Ketone in Mice.
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1981. Changes in rat liver microsomal cytochrome P-450 and enzymatic activities after the inhalation of n-hexane, xy lene, methyl ethyl ketone, and methylchloroform for four weeks.
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1985. Acetone, methyl ethyl ketone, acetonitrile, and other polar aprotic solvents are strong inducers of aneuploidy in Saccharomyces cerevisiae.
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