A highly persistent, lipophilic, brominated organochlorine which is effectively used against nematodes, dibromochloropropane (DBCP) has been produced for agriculture since 1955. In 1975, production of DBCP in the United States reached 25 million lbs. However, investigations with laboratory animals, some of which were published in the early 1960s, have shown that DBCP decreases sperm mobility and spermatogenesis, disturbs the estrous cycle, reduces phagocytosis by white blood cells, and induces malignant tumors. Later studies with procaryotic and eucaryotic cells, including human sperm, have demonstrated DBCP to be mutagenic and to effect the genome adversely. In 1977 many of the employees at the Occidental Chemical plant in Lathrop, California, who had handled DBCP, were found to be either azoospermic or oligospermic. Subsequent surveys of employees handling DBCP at other chemical plants confirmed these findings. In 1977 on edible crops and in 1979 DBCP per se was detected in well waters. As a result of these studies, the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA) in 1977 promulgated regulations restricting the use and handling of DBCP. In 1979, the EPA banned almost all agricultural uses of DBCP.