Definition of Arsine

Arsine: A colorless highly toxic gas. Arsine has a garlic-like or fishy odor. Because arsine is nonirritating and produces no immediate symptoms, persons exposed to hazardous levels of it may be unaware of its presence.

Arsine is water soluble. It is generally shipped in cylinders as a liquefied compressed gas. Exposure frequently occurs when arsine gas is generated while metals or crude ores containing arsenic impurities are treated with acid and this is a common source of exposure.

Inhalation is the major route of exposure. The odor threshold of arsine is 10-fold greater than the permissible exposure limit set by OSHA. Odor is not an adequate indicator of arsine's presence and does not provide reliable warning of hazardous concentrations. Arsine is heavier than air and hazardous concentrations may develop quickly in enclosed, poorly ventilated, or low-lying areas. Initial symptoms (malaise, dizziness, nausea, abdominal pain, and dyspnea) may develop within several hours of exposure to 3 ppm of arsine.

Children exposed to the same levels of arsine as adults may receive larger dose because they have greater lung surface area:body weight ratios and increased minute volumes:weight ratios. In addition, they may be exposed to higher levels than adults in the same location because of their short stature and the higher levels of arsine found nearer to the ground.

Arsine gas is formed when arsenic-containing materials react with freshly formed hydrogen in water or acids. Frequently exposure results when arsenic containing metals (i.e., metal vats) undergo acid washes. Unintentional exposures have also occurred during refining of ores (e.g., lead, copper, zinc, iron, and antimony ores) that contain arsenic. Arsine is used as a dopant in the semiconductor industry and in the manufacture of crystals for fiberoptics and computer chips. It is used infrequently in galvanizing, soldering, etching, burnishing, and lead plating.

Arsine may be fatal if inhaled in sufficient quantities. Its primary toxic effect is due to hemolysis (the breakup of red blood cells), resulting in renal failure. Common initial symptoms of exposure include malaise, headache, thirst, shivering, abdominal pain and dyspnea (difficulty breathing). These symptoms usually occur within 30 to 60 minutes with heavy exposure, but can be delayed for 2 to 24 hours. Hemoglobinuria (the presence of hemoglobin in the urine) usually occurs within hours, jaundice within 1 or 2 days. Aside from causing hemolysis, jaundice, gastroenteritis, and nephritis, arsine is believed to be is carcinogenic (cause cancer)