CompuServe Messages

Michael, PMFJI I've been lurking this forum for a couple of months, but this seems like a good place to say something. I work around the H2S somewhat regularly, have taught the safety course required by law for oil field workers, and just completed my annual safety certification to work in the oil fields in an H2S environment, here are the ANSI 23Z-1972 standards: 0.0002 percent (2ppm) Obvious odor 0.001 percent (10ppm) Beginning eye irritation (OSHA 8 hour max exposure) 0.0015 percent (15 ppm) STEL (Short Term Exposure Limit) 0.01 percent (100 ppm) Coughing, eye irritation, loss of smell in 2-5min 0.02 percent (200 ppm) marked conjunctivitis, respiratory tract irritation in 1 hour 0.05 percent (500 ppm) loss of conciousness, possible death in 30 min-1hr 0.07 percent (700 ppm) Rapid unconciousness, breathing will stop and death will occur if not promptly rescued 0.10 percent (1000 ppm) Immediate unconciousness, early cessation of breathing and death within minutes. Death may occur even if moved to fresh air at once. This is dangerous stuff. The only gas more lethal (other than some specialized chem warfare stuff) is hydrogen cyanide (HCN). Additionally mixtures of 4.3 to 46 pervent volume in air is explosive, it burns to form sulfur dioxide (another poisonous, but less toxic gas), and is water soluable (4 parts H2S to 1 part water at 32 degrees F).