Chronicle 6: Is Chloroprene Really That Bad?
California Proposition 65 requires businesses to provide warnings to Californians about significant exposures to chemicals that cause cancer, birth defects or other reproductive harm. It also requires California to publish a list of chemicals known to cause cancer, birth defects or other reproductive harm. Chloroprene is listed “because it can cause cancer. Exposure to chloroprene may increase the risk of cancer.”
Chloroprene is a chemical used to make a synthetic rubber or neoprene. To be clear, the Prop. 65 listing states that: “neoprene products are unlikely to cause exposure to chloroprene. Levels of chloroprene in most neoprene products are very low.” See the official Prop65 listing here.
The U.S. Environmental Protection Agency (EPA) has classified chloroprene as likely to be carcinogenic to humans.— EPA Listing here.
Interestingly, but not surprisingly, the largest manufacturer of chloroprene in the U.S. submitted in 2021 a letter to the EPA requesting for correction of the EPA’s chloroprene listing. This request was denied by the EPA in March 2022 of this year. Scan the QR code for the official EPA letter.
About 19 companies make chloroprene worldwide in: USA, Canada, Japan, China, France, Germany, Italy, UK, Spain, Russia, Asia-Pacific, Australia, India, South Korea, Latin America, Brazil, Mexico, Middle East, Africa.
So, even though neoprene products like wetsuits do not expose the consumer to chloroprene, consider that those who make chloroprene in these petrochemical plants, that go into making the neoprene wetsuits possible, do have direct exposure to chloroprene. And not just factory workers but those who live near these petrochemical plants as well.
In LaPlace, Louisiana (the only chloroprene plant in the USA), peer-reviewed scientific reports show much higher incidences of at least 2 cancers (respiratory and liver) compared to the national average. These studies contributed to the Prop65 and EPA listing chloroprene as a cancer causing agent.
See the EPA Letter to Denka denying correction to EPA warning of Chloroprene here.
Natural rubber vs synthetic rubber (or chloroprene). The chemical structures are very similar but for the groups highlighted.
Neoprene is a plural form of chloroprene. A polymer is a large number of the same units bonded together. So, stated in another way, neoprene is a polychloroprene or chloroprene rubber. It was the first synthetic rubber made by Dupont in 1931 and in 1937 "neoprene" was coined.
