# NIOSH Pocket Guide to Chemical Hazards
Acetonitrile | CAS 75-05-8
CH3CN | RTECS AL7700000
Synonyms & Trade Names Cyanomethane, Ethyl nitrile, Methyl cyanide [Note: Forms cyanide in the body.] | DOT ID & Guide 1648 131
Exposure Limits | NIOSH REL: TWA 20 ppm (34 mg/m3)
OSHA PEL†: TWA 40 ppm (70 mg/m3)
IDLH 500 ppm | Conversion 1 ppm = 1.68 mg/m3
Physical Description Colorless liquid with an aromatic odor.
MW: 41.1 | BP: 179°F | FRZ: -49°F | Sol: Miscible
VP: 73 mmHg | IP: 12.20 eV |  | Sp.Gr: 0.78
Fl.P(oc): 42°F | UEL: 16.0% | LEL: 3.0% |
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities Strong oxidizers
Measurement Methods NIOSH 1606
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation Provide: Quick drench | First Aid (See procedures) Eye: Irrigate immediately Skin: Water flush immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH Up to 200 ppm: (APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s)/(APF = 10) Any supplied-air respirator Up to 500 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)/(APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(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 organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation nose, throat; asphyxia; nausea, vomiting; chest pain; lassitude (weakness, exhaustion); stupor, convulsions; in animals: liver, kidney damage
Target Organs respiratory system, cardiovascular system, central nervous system, liver, kidneys
See also: INTRODUCTION