No studies are available on oral exposure to manganese in humans and cancer. Oral animal studies on manganese sulfate have shown mixed results, with several studies reporting negative results and one study noting an increased incidence of pancreatic tumors. EPA has classified manganese as a Group D, not classifiable as to carcinogenicity in humans. Manganese is a silver-colored metal that forms compounds in the environment with chemicals such as oxygen, sulfur, and chlorine. It is also used in carbon steel and stainless steel, along with cast iron and superalloys.
Manganese compounds have a variety of uses.
Manganese dioxide is used in the production of dry-cell batteries, matches, fireworks, and the production of other manganese compounds. Manganese chloride is used as a precursor for other manganese compounds and in animal feed, while manganese sulfate is used in glazes and varnishes, in ceramics, and as a nutritional supplement. National Academy of Sciences. Drinking Water and Health. Volume 3 .