Sumitomo chemical Company Ltd.

Japanese chemical company with head offices in Tokyo and Osaka, founded in 1913 out of a copper smelting fertiliser works and listed in Tokyo, one of the country's largest chemical groups. Makes essential chemicals and plastics, energy and functional materials, information technology materials, crop protection chemicals and fertilisers and household insecticides including the Olyset mosquito net, and works in pharmaceuticals through Sumitomo Pharma, running its own research laboratories and a biological environmental science laboratory for toxicology and environmental fate studies.