NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Methylamine

CAS
74-89-5

CH3NH2

RTECS
PF6300000
Synonyms & Trade Names

Aminomethane, Methylamine (anhydrous), Methylamine (aqueous), Monomethylamine
DOT ID & Guide
1061 / 118 (anhydrous)
1235 / 132 (aqueous)

Exposure
Limits

NIOSH REL: TWA 10 ppm (12 mg/m3)
OSHA PEL: TWA 10 ppm (12 mg/m3)
IDLH
100 ppm See: 74895
Conversion
1 ppm = 1.27 mg/m3
Physical Description
Colorless gas with a fish- or ammonia-like odor. [Note: A liquid below 21°F. Shipped as a liquefied compressed gas.]
MW: 31.1
BP: 21°F
FRZ: -136°F
Sol: Soluble
VP: 3.0 atm
IP: 8.97 eV
RGasD: 1.08
Sp.Gr: 0.70 (Liquid at 13°F)
Fl.P: NA (Gas) 14°F (Liquid)
UEL: 20.7%
LEL: 4.9%

Flammable Gas
Incompatibilities & Reactivities

Mercury, strong oxidizers, nitromethane [Note: Corrosive to copper & zinc alloys, aluminum & galvanized surfaces.]
Measurement Methods
OSHA 40
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Prevent skin contact (solution)/Frostbite
Eyes: Prevent eye contact (solution)/Frostbite
Wash skin: When contaminated (solution)
Remove: When wet (flammable)
Change: No recommendation
Provide: Frostbite wash
First Aid
(See procedures)
Eye: Irrigate immediately (solution)/Frostbite
Skin: Water flush immediately (solution)/Frostbite
Breathing: Respiratory support
Swallow: Medical attention immediately (solution)
Respirator Recommendations
NIOSH/OSHA
Up to 100 ppm:
(APF = 50) Any chemical cartridge respirator with a full facepiece and cartridge(s) providing protection against the compound of concern
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern
(APF = 25) Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator 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
Escape:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Important additional information about respirator selection
Exposure Routes
inhalation, skin absorption (solution), ingestion (solution), skin and/or eye contact (solution/liquid)
Symptoms
Irritation eyes, skin, respiratory system; cough; skin, mucous membrane burns; dermatitis; conjunctivitis; liquid: frostbite
Target Organs
Eyes, skin, respiratory system
See also: INTRODUCTION   See ICSC CARD: 0178