2-HEXANONE (METHYL N-BUTYL KETONE; METHYL BUTYL KETONE) | Occupational Safety and Health Administration

2-HEXANONE (METHYL N-BUTYL KETONE; METHYL BUTYL KETONE)†

Chemical Identification
CAS #	591-78-6
Formula	C₆H₁₂O
Synonyms	butyl methyl ketone; MBK; methyl butyl ketone; methyl n-butyl ketone

Physical Properties
Physical description	Colorless liquid with an acetone-like odor.
Boiling point	262°F	Molecular weight	100.2
Freezing point/melting point	-71°F	Vapor pressure	11 mmHg
Flash point	73°F	Vapor density	3.45
Specific gravity	0.812	Ionization potential	9.34 eV
Lower explosive limit (LEL)	1.2%	Upper explosive limit (UEL)	8%
NFPA health rating	2	NFPA fire rating	3
NFPA reactivity rating	0	NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.)	1690
Sampling group
Sampler/Sampling media	CSC tube (100/50 mg) [SKC 226-01]
Sampling time^*
Sampling volume (TWA)^*	20 L
Sampling flow rate (TWA)^*	0.2 L/min
Sampling volume (STEL/Peak/C)^*
Sampling flow rate (STEL/Peak/C)^*
Analytical method instruments	GC-FID
Method reference	OSHA PV2031 (partially validated)
Notes
Special requirements

^* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Bulk/Wipe Method
Wipe Sampler/Sampling media
Bulk Method

On-Site Screening Techniques
Device
Model/Type
Sampling information (see manufacturer instructions)

**Exposure Limits**
OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak		NIOSH REL Up to 10-hour TWA (ST) STEL (C) Ceiling		ACGIH TLV© 8-hour TWA (ST) STEL (C) Ceiling		CAL/OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak
PEL-TWA	100 ppm (410 mg/m³)	REL-TWA	1 ppm (4 mg/m³)	TLV-TWA	5 ppm [1995]	PEL-TWA	1 ppm (4 mg/m³)
PEL-STEL		REL-STEL		TLV-STEL	10 ppm [1995]	PEL-STEL	10 ppm (40 mg/m³)
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	N	Skin notation	N	Skin notation	Y	Skin notation	Y
Notes: See 29 CFR 1910.1000 Table Z-1.		Notes:		Notes: BEI®		Notes:
Health factors: See NIH-NLM PubChem.		IDLH	1600 ppm
Carcinogenic classifications: EPA-1		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Methyl butyl ketone

NIOSH: Pocket Guide to Chemical Hazards - 2-Hexanone

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Methyl n-butyl ketone. See annual publication for most recent information.
Bolt, H.M., Roos, P.H. and Thier, R.: The cytochrome P-450 isoenzyme CYP2E1 in the biological processing of industrial chemicals: consequences for occupational and environmental medicine. Int. Arch. Occup. Environ. Health 76(3): 174-185, 2003.
Bos, P.M.J., de Mik, G. and Bragt, P.C.: Critical review of the toxicity of methyl n-butyl ketone: risk from occupational exposure. Am. J. Ind. Med. 20(2): 175-194, 1991.
Pohanish, R.P. (editor): Methyl n-Butyl Ketone. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1535-1538.
Zhu, M., Spink, D.C., Yan, B., Bank, S. and DeCaprio A.P.: Inhibition of 2,5-hexanedione-induced protein cross-linking by biological thiols: chemical mechanisms and toxicological implications. Chem. Res. Toxicol. 8(5): 764-771, 1995.

Last Updated Date : 01/28/2021

2-HEXANONE (METHYL N-BUTYL KETONE; METHYL BUTYL KETONE)†

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References