2. RELEVANCE TO PUBLIC HEALTH 2.1 BACKGROUND AND ENVIRONMENTAL EXPOSURES TO DICHLOROPROPENES IN THE UNITED STATES 1,3-Dichloropropene is a mixture of volatile cis and trans isomers and is primarily used as a nematocide

1,3-Dichloropropene is a mixture of volatile cis and trans isomers and is primarily used as a nematocide to fumigate soil before planting. Commercial formulations of 1,3-dichloropropene contain stabilizers to inhibit degradation of the compound (Table 3-1). Older formulations contained chroropicrin or epichlorohydrin, whereas currently, the less toxic epoxidized soybean oil is used as a stabilizer. 1,3-Di­ chloropropene is released to the atmosphere in fugitive or accidental emissions from industrial sources (e.g., petroleum refineries, sewage treatment facilities, and electricity-generating power facilities) and also during its use as a fumigant. Accidental discharges into surface waters from industrial sources or leaching into groundwater from hazardous waste sites or agricultural uses also occur.