(Arsenic hydride, arsenic trihydride, hydrogen arsenide)

CAS 7784-42-1





Physical Properties

Colorless gas

bp -62 C, mp -117 °C

Slightly soluble in water (0.07 g/100 mL at 20 °C)



Garlic-like odor detectable at 0.5 to 1 ppm

Vapor Density

2.7 (air = 1.0)


Vapor Pressure

>760 mmHg at 20 °C


Flash Point

< -62 °C


Autoignition Temperature

Not established. Decomposes at 232 to 300 °C to form elemental arsenic and hydrogen.

Toxicity Data

LCLO inhal (rat)

94 ppm (300 mg/m3; 15 min)



0.05 ppm (0.2 mg/m3)



0.05 ppm (0.16 mg/m3)

Major Hazards

Extremely toxic gas that destroys red blood cells and can cause widespread organ injury and death.


The acute toxicity of arsine by inhalation is extremely high. This substance is a powerful systemic toxin with a strong affinity for the hemoglobin in the blood, causing hemolysis. Acute inhalation of arsine can cause the breakdown of red blood cells and hemoglobin, impairment of kidney function, damage to the liver and heart, electroencephalogram abnormality, hemolytic anemia, and death due to kidney or heart failure. Symptoms may be delayed for several hours, particularly if very low concentrations have been inhaled. Symptoms of exposure to arsine may include headache, malaise, weakness, dizziness, breathing difficulty, abdominal pain, nausea, vomiting, jaundice, dark red (bloody) urine followed by absence of urination, pulmonary edema, and coma. Exposure to a concentration of 5 to 10 ppm in air for several minutes may be hazardous to human health. The minimum amount of arsine detectable by odor is about 0.5 ppm; since the permissible exposure limit is 0.05 ppm, arsine does not have adequate warning properties to avoid overexposure.

In cases where the amount of inhaled arsine is insufficient to produce acute effects, or where small quantities are inhaled over prolonged periods, destruction of red blood cells

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