Technical Bulletin No. 0691: Health Effects of Reduced Sulfur Gases

The reduced sulfur gases hydrogen sulfide, methyl mercaptan, dimethyl disulfide and dimethyl sulfide, are produced in kraft pulp mills during pulp digestion and may be released, generally at low levels, into the atmosphere. Although high concentrations of H2S are acutely toxic, exposure to low (less than 20 ppm) concentrations of H2S is not generally associated with significant adverse health effects. Based upon animal studies, both methyl mercaptan and dimethyl disulfide appear to be somewhat less toxic than hydrogen sulfide, but produce similar effects, while dimethyl sulfide is about 100 times less toxic.