1,2-Dichloroethane (Ethylene dichloride)

Ethylene dichloride (EDC) has been produced since the 1850s and became one of the highest-volume industrial chemicals in the 20th century primarily as an intermediate in vinyl chloride monomer (VCM) production — over 80% of EDC produced is used to make VCM, which is then polymerized to PVC [1]. Production is concentrated along the Gulf Coast in Louisiana and Texas, where the chemical corridor known as "Cancer Alley" includes numerous EDC/VCM production facilities. Historical contamination from PVC and EDC manufacturing has contaminated soil and groundwater at dozens of locations [2]. EDC was also used as a lead scavenger in leaded gasoline (removing lead deposits from engines), as a fumigant for grain, and as a solvent. Its environmental persistence and widespread production have made it one of the most common Superfund organic contaminants [3].

Occupational inhalation in chemical manufacturing facilities that produce or use EDC is the primary high-dose route [1]. Community air near EDC/PVC production facilities — particularly in industrial corridors — is a significant exposure source. Contaminated groundwater near industrial sites and Superfund sites is a drinking water concern [2]. Historically, EDC was used as a fumigant on stored grain, and residues in grain-based foods were a consumer dietary concern. Vapor intrusion from EDC-contaminated soil into homes is a pathway in affected communities [3].

EDC is classified as a probable human carcinogen (IARC Group 2A) with evidence for liver cancer, hemangiosarcoma, and possibly lung cancer in occupationally exposed workers [1]. The mechanism involves metabolic activation by cytochrome P450 enzymes to chloroacetaldehyde and chloroethylene oxide — reactive metabolites that form DNA adducts and alkylate proteins. Acute high-level EDC exposure affects the CNS (headache, dizziness, unconsciousness) and causes severe liver and kidney damage [2]. Long-term lower-level exposure is associated with liver function abnormalities, neurological effects, and the elevated cancer risks seen in production worker cohorts. EDC is also a reproductive toxin in animal studies [3].

Workers in EDC and VCM production, PVC manufacturing, and industries using EDC as a solvent carry the highest occupational burdens [1]. Communities in Louisiana's industrial corridor near PVC/EDC facilities have documented elevated cancer rates that have drawn regulatory attention [2]. People who drink groundwater from private wells in areas with EDC contamination from industrial sites face drinking water exposure.

If you live near EDC-producing facilities or in an area with known EDC groundwater contamination, use a certified reverse-osmosis or carbon block filter on your drinking water [1]. Support EPA enforcement of air emissions standards at nearby production facilities and review facility emissions data through EPA's ECHO database [2]. Workers in EDC-using industries: implement engineering controls (local exhaust ventilation, closed systems), use appropriate PPE, and have liver function testing as part of occupational health monitoring [3].