Colorless with the characteristic foul odor of rotten eggs. It is toxic, corrosive, flammable, and explosive.

Heavier than air, density = 1,411 kg/m3

Lower explosive limit (LEL) = 4 %vol

Health exposure limits (Directive 2009/161/EU):
8 hours TWA = 5 ppm (7 mg/m3)
15 mins STEL = 10 ppm (14 mg/m3)