This statement concerned the NIOSH investigation of occupational exposure to dibromochloropropane (96128) (DBCP) and possible reduced sperm counts among workers handling this compound. Due to the concern of one worker, a chemical company, the Oxy Chem facility in Lathrop, California, contacted NIOSH for assistance in determining whether a health problem existed at their facility. Research indicated that there was a problem and resulted in the identification of DBCP as the offending agent. Confirmation was sought by testing workers at other sites involved in the production of this pesticide. Their research supported the findings that DBCP was the agent responsible for the testicular toxicity. Literature studies revealed DBCP to be an animal carcinogen and a relatively potent mutagen as well. A proposed emergency standard for occupational exposure to DBCP was submitted to OSHA in early September of 1977 setting an exposure limit and requiring medical surveillance guidelines. A symposium on DBCP was held so that all interested parties might share available data. All participants agreed to the need for a registry of individuals exposed to DBCP. Research has now spread to the possible reproductive effects of exposure to other chemicals similar in structure to DBCP.