This volume is part of a series containing critically assessed data and recommendations for occupational safety officers, industrial hygienists, and human and animal toxicologists. It has been compiled and reviewed under internationally co-ordinated programmes for establishing the risk potential of existing chemicals to prevent health hazards at the working place. This volume contains data on the following chemicals: N,N'-Diphenyi-p-phenylenediamine, Benzotrifluoride, Carbonic acid diethyl ester, Cyanuric acid, Tetrahydrothiophene, 1,4-Butanediol, Trioxane, Diethylenetriamine, 4-Aminobenzene sulfonic acid, Acetoacetic acid ethyl ester, N-Methylolmethacrylamide, Tetrafluoroboric acid, and 4-Isopropalphenylisocyanate.