Arsine Detection

Arsine Detection

Arsine

Arsine is a colourless gas. Though odourless in its pure form, it has an unpleasant garlic-like odour when exposed to air. It is usually detectable by smell at around 0.5 ppm. It is not combustible but will decompose into arsenic and hydrogen above 300° C. The rate of decomposition can be facilitated by the presence of light, humidity and catalysts such as aluminium.
 
It is extremely toxic due to its ability to bind with oxyhaemoglobin in the blood causing acute haemolysis (destruction of red blood cells), consequent anaemia and subsequent kidney damage. Its major industrial application is in the production of semi-conductors.
 
Arsine Characteristics
Synonyms Arsenic hydride, Arsenic trihydride, Hydrogen arsenide
CAS No. 7784-42-1
Chemical formula AsH3
Vapour density 2.66 (air = 1)
Safe Work Australia ES TWA 0.05 ppm
STEL _
Flammable limits LEL -
UEL _
Equipment group ---
Temperature classification ---
Chemical/physical properties Arsine is a colourless gas. Though odourless in its pure form, it has an unpleasant garlic-like odour when exposred to air. It is usually detectable by smell at around 0.5 ppm. It is not combustible but will decompose into arsenic and hydrogen above 300° C. 
Hazardous properties It is extremely toxic due to its ability to bind with oxyhaemoglobin in the blood causing acute haemolysis (destruction of red blood cells), consequent anaemia and subsequent kidney damage.
Occurrence/Uses Its major industrial application is in the production of semi-conductors.
Detectors available Electrochemical (0 – 0.5 ppm)
Colorimetric paper tape (0 – 500 ppb)
Gas detector tube (0.05 – 160 ppm)
Suggested alarm levels Lo: 0.05 ppm
Hi: 0.15 ppm
Notes