Chloroprene

Chloroprene was first synthesized in 1930 at DuPont, which commercialized neoprene rubber the same year [1]. Neoprene's heat resistance, weather resistance, and flexibility made it indispensable for industrial applications — it became standard for electrical wire coatings, automobile belts and hoses, wetsuits, and adhesives. The DuPont plant in LaPlace, Louisiana produced chloroprene for decades; DuPont sold it to Denka in 2015. The community of Reserve, Louisiana — a predominantly African American community that borders the plant — has been fighting for attention to the cancer burden in their parish for years [2]. EPA air monitoring found chloroprene concentrations in the community that translated to lifetime cancer risks of 1 in 100 — meaning one in every hundred residents would be expected to develop cancer from air exposure alone, roughly 20,000 times EPA's acceptable risk threshold. It took years of advocacy, media attention, and the work of environmental justice attorney Sharon Lavigne to force regulatory action [3].

The primary non-occupational exposure pathway for affected communities is inhalation of ambient air near chloroprene production or use facilities [1]. The LaPlace/Reserve, Louisiana community represents the most documented case of high-level community chloroprene air exposure. Occupational inhalation exposure occurs in neoprene manufacturing, chloroprene production, and industries that process neoprene rubber [2]. Consumer products made from cured neoprene do not release significant chloroprene. Some neoprene manufacturing facilities emit chloroprene in other parts of the US [3].

Chloroprene is classified as likely carcinogenic to humans by the EPA, based on strong evidence for liver cancer and lung cancer in animal studies and elevated cancer rates in worker cohort studies [1]. IARC classifies it as a possible carcinogen (Group 2B). The EPA's unit risk estimate for chloroprene — the increase in cancer risk per unit concentration in air — is one of the highest of any regulated air pollutant [2]. The Louisiana community's exposure represents an environmental justice crisis that reflects decades of disparate siting of industrial hazards in communities with less political power. Reproductive toxicity, liver damage, and immune effects are also associated with chloroprene exposure in worker studies [3].

The community of Reserve and St. John the Baptist Parish, Louisiana near the Denka facility faces the highest documented community chloroprene exposure in the US [1]. Workers in neoprene manufacturing and chloroprene production carry occupational exposure risks. Other communities near neoprene manufacturing facilities should check EPA's NATA database for estimated chloroprene cancer risk [2].

For the Reserve, Louisiana community and similar communities near chloroprene facilities: stay indoors with windows closed and air conditioning running on high-emission days; use HEPA air purifiers to reduce indoor particle concentrations [1]. Engage with your local air quality agency and EPA regional office about enforcing emission standards and seeking stricter limits [2]. The case of Sharon Lavigne and RISE St. James demonstrates that community organizing and working with legal and environmental justice organizations can force regulatory action — connect with environmental justice groups like the Deep South Center for Environmental Justice or Earthjustice for support [3]. Workers in chloroprene facilities should use closed systems, local exhaust ventilation, and appropriate PPE, with annual liver function tests and chest imaging.