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2-Butanone

General Description

  • Synonyms: Methyl ethyl ketone; MEK; Ethyl methyl ketone; Methylethylketone; Methyl acetone
  • OSHA IMIS Code Number: 0430
  • Chemical Abstracts Service (CAS) Registry Number: 78-93-3
  • NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: EL6475000
  • Department of Transportation Regulation Number (49 CFR 172.101) and Emergency Response Guidebook: 1193 127; 1232 127
  • NIOSH Pocket Guide to Chemical Hazards, 2-Butanone: Physical description, chemical properties, potentially hazardous incompatibilities, and more
  • U.S. Environmental Protection Agency (EPA) Hazard Summary, 2-Butanone: Uses, sources and potential exposure, acute and chronic health hazard information, and more

Exposure Limits

Exposure Limit Limit Values HE Codes Health Factors and Target Organs

OSHA Permissible Exposure Limit (PEL) - General Industry
See 29 CFR 1910.1000 Table Z-1

200 ppm
(590 mg/m3) TWA

HE16

Irritation of the eyes, nose, and throat

OSHA PEL - Construction Industry
See 29 CFR 1926.55 Appendix A

200 ppm
(590 mg/m3) TWA

HE16 Irritation of the eyes, nose, and throat

OSHA PEL - Shipyard Employment
See 29 CFR 1915.1000 Table Z-Shipyards

200 ppm
(590 mg/m3) TWA

HE16

Irritation of the eyes, nose, and throat

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL) (REL listed under ketones)

200 ppm
(590 mg/m3) TWA

300 ppm
(885 mg/m3) STEL

HE8

Narcosis (central nervous system depression)

HE16

Irritation of the eyes, nose, and throat

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2001) (TLV listed under methyl ethyl ketone [MEK])

200 ppm
(590 mg/m3) TWA

300 ppm
(885 mg/m3) STEL

BEI

HE7

Central nervous system effects and peripheral neuropathy

HE16

Irritation of the eyes, nose, and throat

CAL/OSHA PELs

200 ppm
(590 mg/m3) TWA

300 ppm
(885 mg/m3) STEL

HE7

Central nervous system effects and peripheral neuropathy

HE16 Irritation of the eyes, nose, and throat
  • Carcinogenic Classification:
  • EPA Inhalation Reference Concentration (RfC): 5 mg/m3
  • Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Level (MRL): Not established
  • NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 3,000 ppm
  • Notes on Other Potential Health Effects and Hazards
    1. 2-Butanone is highly flammable (NIOSH/IPCS 1998; Pohanish 2002).
    2. 2-Butanone is metabolized by reduction to 2-butanol or oxidation to 3-hydroxy-2-butanone, which is subsequently reduced to 2,3-butanediol. The presence of unchanged 2-butanone in urine is the suggested biological exposure index (BEI) because it is strongly correlated with levels in air (EPA 2003a, 2003b).
    3. Physiological differences between men and women, as well as differences due to sex hormone levels, can impact urinary concentrations of biomarkers of exposure for 2-butanone (Tomicic et al. 2011).
  • Literature Basis:
    • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Methyl Ethyl Ketone. 2001.
    • EPA: Integrated Risk Information System - Methyl ethyl ketone (MEK) (CASRN 78-93-3). September 2003a.
    • EPA: Toxicological Review of Methyl Ethyl Ketone (PDF) (CAS No. 78-93-3). September 2003b.
    • NIOSH: Criteria for a Recommended Standard - Occupational Exposure to Ketones. 1978.
    • NIOSH: Occupational Safety and Health Guideline for 2-Butanone. 1988.
    • NIOSH/IPCS: International Chemical Safety Cards - Methyl ethyl ketone. March 1998.
    • Pohanish, R.P. (editor): Methyl ethyl ketone. In: Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, pp. 1566-1568, 2002.
    • Tomicic, C, Berode, M, Oppliger, A, Castella, V, Leyvraz, F, Praz-Christinaz, SM, Danuser, B: Sex differences in urinary levels of several biological indicators of exposure - a human volunteer study. Toxicol Lett. 202(3):218-25, May 10, 2011.
  • Date Last Revised: 09/06/2012

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):
  • Anasorb CMS
  • maximum volume: 12 Liters
  • maximum flow rate: 0.05 L/min
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: (99:1) Carbon Disulfide:N,N-Dimethylformamide
  • method reference: OSHA Analytical Method (OSHA 1004)
  • method classification: Fully Validated
  • Diffusive Sampler (SKC 575-002 Passive Sampler)
  • minimum time: 5 Minutes
  • maximum time: 240 Minutes
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: (99:1) Carbon Disulfide:N,N-Dimethylformamide
  • method reference: OSHA Analytical Method (OSHA 1004)
  • method classification: Fully Validated
  • note: Persons using diffusive samplers to monitor workplace air must ensure that the sampling devices are properly closed before transporting such devices to the laboratory for analysis. The device will continue to sample until properly closed. Diffusive sampler accessories used for analysis of samplers must be included with transported samples. Persons using such devices must provide sampling-site station barometric pressure and temperature to the analytical laboratory to improve accuracy of sampling results.
  • Diffusive Sampler (3M 3520 Organic Vapor Monitor)
  • minimum time: 5 Minutes
  • maximum time: 240 Minutes
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: (99:1) Carbon Disulfide:N,N-Dimethylformamide
  • method reference: OSHA Analytical Method (OSHA 1004)
  • method classification: Fully Validated
  • note: Persons using diffusive samplers to monitor workplace air must ensure that the sampling devices are properly closed before transporting such devices to the laboratory for analysis. The device will continue to sample until properly closed. Diffusive sampler accessories used for analysis of samplers must be included with transported samples. Persons using such devices must provide sampling-site station barometric pressure and temperature to the analytical laboratory to improve accuracy of sampling results.
  • Carbosieve S-III Tube (130/65 mg sections; 60/80 mesh)
  • maximum volume: 3 Liters
  • maximum flow rate: 0.05 L/min (TWA)
  • maximum volume: 0.75 Liters
  • maximum flow rate: 0.05 L/min (STEL)
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: (99:1) Carbon Disulfide:Dimethyl Formamide
  • method reference: OSHA Analytical Method (OSHA 84)
  • method classification: Fully Validated
  • Two Silica Gel Tubes in series (150/75mg sections, 20/40 mesh)
  • maximum volume: 3 Liters
  • maximum flow rate: 0.1 L/min (TWA)
  • maximum volume: 1.5 Liters
  • maximum flow rate: 0.1 L/min (STEL)
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: Dimethyl Sulfoxide
  • alternate analytical solvent: Ethanol
  • method reference: OSHA Analytical Method (OSHA 16)
  • method classification: Fully Validated
  • Anasorb 747 (150/75 mg sections; 20/40 mesh)
  • maximum volume: 12 Liters
  • maximum flow rate: 0.20 L/min
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: Carbon disulfide
  • method reference: NIOSH Analytical Method (NIOSH 2500 (PDF))
  • method classification: Fully Validated

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