PVC Pipes and Drinking Safety

Polyvinyl chloride (PVC) is a common plastic used in pipes. Some PVC pipes can leach vinyl chloride, a known carcinogen, into drinking water.

Chemistry

• PVC belongs to a class of compounds known as polymers. Polymers are very large molecules created by linking together smaller molecules. In the case of PVC, the smaller molecule is vinyl chloride monomer (VCM). Finished PVC will typically still contain some unreacted VCM.

Toxicity

• VCM is a known carcinogen, causing cancerous tumors in the brain, lungs, liver and various tissues in humans.

Early-Era PVC

• "Early-era" PVC refers to PVC pipe manufactured prior to 1977. According to the U.S. Environmental Protection Agency (EPA), early-era PVC can leach VCM into drinking water to levels that exceed the maximum contaminant level of 2 micrograms per liter of water.

PVC Today

• Starting in 1977, PVC pipe manufacturers drastically improved their manufacturing processes to reduce VCM levels in manufactured pipe. Some PVC pipe is manufactured to a specification called "NSF-61" or "NSF-PW," specifically for use in applications involving drinking water.

Affected Areas

• The greatest threat from PVC pipes is from early-era PVC used in water mains. The government is not certain of how many miles of early-era PVC are installed in the U.S. The states of Kansas, Texas, Iowa, Arkansas and Missouri appear to be the most affected.