This Current Intelligence Bulletin (CIB) briefly presents information on the genotoxic hazards associated with diethylcarbamoyl-chloride (88108) (DECC). A study of the mutagenic potential of DECC found that it was mutagenic in two strains of Escherichia-coli, (WP-2) and (WP-2S). DECC, however, was not as potent a mutagen as the closely related analog dimethylcarbamoyl- chloride (79447) (DMCC). DMCC was found to have carcinogenic activity in laboratory animals after subcutaneous, intraperitoneal, and inhalation exposure, as noted in another NIOSH CIB. Annual production of DECC in recent years amounted to less than 15000 pounds. The only known commercial use of DECC in the United States was as an intermediate in the synthesis of diethylcarbamazine- citrate, a pharmaceutical used as an anthelmintic (worming agent). Diethylcarbamazine-citrate is said to be produced and marketed as Hetrazan and Caricide by Lederle Laboratories, a division of the American Cyanamide Company.