Table 1
H2S concentration for human contact time (Maddox, 1982).
Period of exposure | Parts of H2S per million parts of air (ppm) |
---|---|
Maximum allowable concentration for prolonged exposure | 10 |
Slight symptoms after exposure of several hours | 70-150 |
Maximum concentration that can be inhaled for 1 h without serious consequences | 170-300 |
Dangerous after exposure of 30 min to one hour | 400-500 |
Fatal in exposure of 30 min or less | 600-800 |