Vinyl chloride

Vinyl chloride was first used as an anesthetic in the early 20th century and became a crucial industrial monomer for polyvinyl chloride (PVC) production from the 1940s onward [1]. Its toxicity was recognized gradually and tragically. In the 1960s and 1970s, workers at PVC manufacturing plants began developing an unusual condition: their fingertips were turning white and dying (a condition called acroosteolysis), and some were dying of an extremely rare liver cancer — hepatic angiosarcoma [2]. The vinyl chloride industry initially suppressed evidence of these effects. When the truth emerged, OSHA established strict workplace standards in 1974. Today, vinyl chloride enters the environment primarily as a degradation product of TCE and PCE — when those chlorinated solvents break down naturally in groundwater, vinyl chloride is a toxic intermediate. The East Palestine derailment in February 2023 involved the controlled burn of approximately 115,000 gallons of vinyl chloride, creating a massive release of both the chemical and its combustion products [3].

Workers in PVC manufacturing and chemical production face the highest exposures through inhalation [1]. For the general public, contaminated groundwater near Superfund sites (where TCE or PCE has degraded to vinyl chloride) and near PVC manufacturing facilities is the primary concern. Vinyl chloride is extremely volatile and readily enters indoor air via vapor intrusion from contaminated soil [2]. New PVC products — especially children's toys, shower curtains, and flexible PVC items — can release vinyl chloride as they off-gas initially, though concentrations drop rapidly. Community exposures near industrial facilities and following chemical accidents like East Palestine involve ambient air [3].

Vinyl chloride is one of only a handful of chemicals where a specific, rare cancer — hepatic angiosarcoma (a cancer of the blood vessels lining the liver) — is used as a sentinel disease indicating exposure [1]. It is classified as a known human carcinogen. The mechanism involves metabolic activation of vinyl chloride to reactive epoxides that directly alkylate and mutate the TP53 and ras tumor suppressor genes. Beyond the signature liver cancer, vinyl chloride is associated with liver cirrhosis, Raynaud's phenomenon (blood vessel spasm in fingers), and acroosteolysis (bone dissolution in fingertips) [2]. Brain and lung cancers are also elevated in exposed populations. At high acute exposures, vinyl chloride acts as a central nervous system depressant causing dizziness and loss of consciousness [3].

PVC manufacturing workers who were employed before modern exposure controls are at highest historical risk of liver angiosarcoma [1]. Communities living near TCE/PCE-contaminated groundwater sites — where natural degradation has produced vinyl chloride — face drinking water risk. Residents near the East Palestine derailment site should follow state monitoring guidance and may benefit from air and water testing [2]. People with pre-existing liver conditions, including those with hepatitis B or C, may be more susceptible to vinyl chloride's liver-damaging effects.

If you live near a Superfund site or chemical contamination plume, check your state's groundwater monitoring data and use a certified reverse-osmosis or activated-carbon block filter on your drinking water [1]. For vapor intrusion from contaminated soil, contact your state environmental agency for free indoor air testing in affected neighborhoods. When purchasing new PVC products, let them air out in a garage or outdoors before bringing them into your home [2]. Reduce PVC use where practical — look for PVC-free shower curtains (EVA alternatives), food containers, and children's toys. Workers in chemical manufacturing and PVC production should have baseline and periodic liver function testing and abdominal imaging [3].