NIOSH Pocket Guide to Chemical Hazards


CAS 7784-42-1


RTECS CG6475000
Synonyms & Trade Names
Arsenic hydride, Arsenic trihydride, Arseniuretted hydrogen, Arsenous hydride, Hydrogen arsenide
DOT ID & Guide
2188 119


NIOSH REL: Ca C 0.002 mg/m3 [15-minute] See Appendix A
OSHA PEL: TWA 0.05 ppm (0.2 mg/m3)
IDLH Ca [3 ppm] See: 7784421 Conversion 1 ppm = 3.19 mg/m3
Physical Description
Colorless gas with a mild, garlic-like odor. [Note: Shipped as a liquefied compressed gas.]
MW: 78.0
BP: -81°F
FRZ: -179°F
Sol: 20%
VP(70°F): 14.9 atm
IP: 9.89 eV
RGasD: 2.69

Fl.P: NA (Gas)
UEL: 78%
LEL: 5.1%

Flammable Gas
Incompatibilities & Reactivities
Strong oxidizers, chlorine, nitric acid [Note: Decomposes above 446°F. There is a high potential for the generation of arsine gas when inorganic arsenic is exposed to nascent (freshly formed) hydrogen.]
Measurement Methods
NIOSH 6001; OSHA ID105
See: NMAM or OSHA Methods
Personal Protection & Sanitation (See protection)
Skin: Frostbite
Eyes: Frostbite
Wash skin: No recommendation
Remove: When wet (flammable)
Change: No recommendation
Provide: Frostbite wash
First Aid (See procedures)
Eye: Frostbite
Skin: Frostbite
Breathing: Respiratory support

Important additional information about respirator selection
Respirator Recommendations NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(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 canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact (liquid)
Symptoms Headache, malaise (vague feeling of discomfort), lassitude (weakness, exhaustion), dizziness; dyspnea (breathing difficulty); abdominal, back pain; nausea, vomiting; bronze skin; hematuria (blood in the urine); jaundice; peripheral neuropathy; liquid: frostbite; [potential occupational carcinogen]
Target Organs Blood, kidneys, liver

Cancer Site [lung & lymphatic cancer]
See also: INTRODUCTION   See ICSC CARD: 0222   See MEDICAL TESTS: 0018