METHYL CHLOROFORM (1,1,1-TRICHLOROETHANE) | Occupational Safety and Health Administration

METHYL CHLOROFORM (1,1,1-TRICHLOROETHANE)†

Chemical Identification
CAS #	71-55-6
Formula	C₂H₃Cl₃
Synonyms	chlorothene; 1,1,1-trichloroethane; 1,1,1-trichloroethane (stabilized)

Physical Properties
Physical description	Colorless liquid with a sweet, chloroform-like odor.
Boiling point	165°F	Molecular weight	133.4
Freezing point/melting point	-26.5°F	Vapor pressure	100 mmHg
Flash point	>200°F	Vapor density	4.6
Specific gravity	1.31	Ionization potential	11.00 eV
Lower explosive limit (LEL)	7.5%	Upper explosive limit (UEL)	12.5%
NFPA health rating	2	NFPA fire rating	1
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.)	1720
Sampling group
Sampler/Sampling media	CSC tube (100/50 mg) [SKC 226-01]
Sampling time^*
Sampling volume (TWA)^*	3 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 14 (fully 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	350 ppm (1900 mg/m³)	REL-TWA		TLV-TWA	350 ppm [1992]	PEL-TWA	350 ppm (1900 mg/m³)
PEL-STEL		REL-STEL		TLV-STEL	450 ppm [1992]	PEL-STEL	450 ppm (2450 mg/m³)
PEL-C		REL-C	350 ppm (1900 mg/m³) [15 minutes]	TLV-C		PEL-C	800 ppm
Skin notation	N	Skin notation	N	Skin notation	N	Skin notation	N
Notes: See 29 CFR 1910.1000 Table Z-1.		Notes:		Notes: BEI®		Notes:
Health factors: See NIH-NLM PubChem.		IDLH	700 ppm
Carcinogenic classifications: IARC-3, TLV-A4, EPA-II		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3: 350 ppm/700 ppm/3500 ppm

Additional Resources and Literature References

NOAA: CAMEO Chemicals - 1,1,1-Trichloroethane

NIOSH: Pocket Guide to Chemical Hazards - Methyl chloroform

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Methyl chloroform. See annual publication for most recent information.
EPA Air Toxics Website: Methyl chloroform (1,1,1-Trichloroethane). U.S. Environmental Protection Agency Technology Transfer Network.
Cohen, C. and Frank, A.L.: Liver disease following occupational exposure to 1,1,1-trichloroethane: A case study. Am. J. Ind. Med. 26(2):237-241, 1994.
House, R.A., Liss, G.M., Wills, M.C. and Holness, D.L.: Paresthesias and sensory neuropathy due to 1,1,1-trichloroethane. J. Occup. Environ. Med. 38(2): 123-124, 1996.
Pohanish, R.P. (editor): 1,1,1-Trichloroethane. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 2245-2248.
Tay, P., Pinnagoda, J., Sam, C.T., Ho, S.F., Tan, K.T. and Ong, C.N.: Environmental and biological monitoring of occupational exposure to 1,1,1-trichloroethane. Occup. Med. (Lond.) 45(3): 147-150, 1995.

Last Updated Date : 01/05/2021

METHYL CHLOROFORM (1,1,1-TRICHLOROETHANE)†

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References