What Is Vinyl Chloride, and Is It Dangerous?

Vinyl chloride is a colorless gas with a mild, sweet odor that does not occur naturally, according to the Agency for Toxic Substances and Disease Registry. It is used to make polyvinyl chloride, or PVC, which is used in plastic products including pipes, wire and cable coatings, and packaging materials.

ATSDR says you can be exposed by breathing vinyl chloride released from plastic manufacturing facilities, hazardous waste sites and landfills, and from cigarette and cigar smoke, and that its vapor can get into the indoor air of a home or business built on contaminated ground. It says the levels typically found in the environment are lower than levels known to cause health problems. Breathing high levels can make you feel dizzy or sleepy, breathing very high levels can cause you to pass out, and breathing extremely high levels can cause death, and some people who breathed vinyl chloride for several years have changes in the structure of their livers.

The US Department of Health and Human Services has classified vinyl chloride as known to be a human carcinogen, the EPA classifies it as a known human carcinogen by inhalation, and IARC has determined that it is carcinogenic to humans. ATSDR says vinyl chloride can be measured in the breath, and its main breakdown product in urine, but only shortly after exposure.