A review of developments during the last decade on the health and environmental safety of organic colorants focused on their toxicological properties. Toxicological hazards associated with dyes include skin sensitization, typically due to impurtieies, or, in some cases, due to disperse dyes from the azo and anthraquinone chemical classes. Also, respiratory sensitization resulting from reactive dyes has occurred. The International Agency for Research on Cancer has evaluated the carcinogenicity of 44 individual organic colorants and benzidine based dyes. Azo dyes have the most data available substantiating potential carcinogenicity. Organic pigments generally have low toxicity due to low bioavailability. An extensive database, which contains the toxicological properties of organic colorants, exists. Risk assessment is a part of the European Union regulatory criteria, which helps provide a balanced approach to assessing exposure levels and hazard guidelines. numerous refs.