Quote:
Originally Posted by Coolhand
I thought the TVEL of H2S had been reduced to 5ppm?
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The values differ from place to place. The TLV (
Threshold Limit Value) is determined by ACGIH (
American Conference of Governmental Industrial Hygienists) and that is also 5PPM. I am not sure if TVEL (E may mean Exposure) is derived from ACGIH or if if is an independent "standard". The TLV values are recommendations only but are adopted by some enforcement agencies and not by others. In most of EU and all of Canada/US the TLV for H2S has not been adapted (different story for other gases). The TLV for H2S is, however, may soon change to 2PPM.
Either way the smell from the sewers (in open air) is a nuisance at worst and as bad as it may smell in not a general health risk.