NIOSH Pocket Guide to Chemical Hazards

Methyl chloroform

CAS 71-55-6


RTECS KJ2975000
Synonyms & Trade Names
Chlorothene; 1,1,1-Trichloroethane; 1,1,1-Trichloroethane (stabilized)
DOT ID & Guide
2831 160


NIOSH REL: C 350 ppm (1900 mg/m3) [15-minute] See Appendix C (Chloroethanes)
OSHA PEL†: TWA 350 ppm (1900 mg/m3)
IDLH 700 ppm See: 71556 Conversion 1 ppm = 5.46 mg/m3
Physical Description
Colorless liquid with a mild, chloroform-like odor.
MW: 133.4
BP: 165°F
FRZ: -23°F
Sol: 0.4%
VP: 100 mmHg
IP: 11.00 eV

Sp.Gr: 1.34
Fl.P: ?
UEL: 12.5%
LEL: 7.5%

Combustible Liquid, but burns with difficulty.
Incompatibilities & Reactivities
Strong caustics; strong oxidizers; chemically-active metals such as zinc, aluminum, magnesium powders, sodium & potassium; water [Note: Reacts slowly with water to form hydrochloric acid.]
Measurement Methods
NIOSH 1003
See: NMAM or OSHA Methods
Personal Protection & Sanitation (See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet or contaminated
Change: No recommendation

First Aid (See procedures)
Eye: Irrigate immediately
Skin: Soap wash promptly
Breathing: Respiratory support
Swallow: Medical attention immediately
Important additional information about respirator selection
Respirator Recommendations NIOSH/OSHA
Up to 700 ppm:
(APF = 10) Any supplied-air respirator*
(APF = 50) Any self-contained breathing apparatus with a full facepiece
Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin; headache, lassitude (weakness, exhaustion), central nervous system depression, poor equilibrium; dermatitis; cardiac arrhythmias; liver damage
Target Organs Eyes, skin, central nervous system, cardiovascular system, liver
See also: INTRODUCTION   See ICSC CARD: 0079   See MEDICAL TESTS: 0141