As part of its "Programme for the prevention of health hazards caused by industrial substances", the Berufsge­ nossenschaft der chemischen Industrie (BG Chemie, Em­ ployment Accident Insurance Fund of the Chemical Indus­ try) began in 1977 to investigate the toxicity of those chemicals which are widely used, have many different ap­ plications and are suspected of being dangerous to health, in particular of having long-term effects. The in­ vestigations consist of a literature search and - depending on the results - commissions of experimental studies. It is hoped by means of this testing to close gaps in our know­ ledge and to increase the scientific validity of the required risk assessments. The results of the toxicological