DuPont Chemical's Washington Works on the Ohio River, just down from Marietta, Ohio, and Parkersburg, West Virginia.

For 50 years, DuPont has manufactured “Teflon” chemicals and used them to keep the grease and stains away from products such as cookware, carpets, clothing, and fast food wrapping.

However, DuPont has known since as early as the 1960s that these chemicals can cause serious health hazards to workers and the public. Internal warnings from DuPont scientists and medical studies conducted on workers during the 1970’s and 1980’s were hidden from the public until they were unearthed in lawsuits over the past 6 years. The studies showed that DuPont knew Teflon chemicals would build up in human blood, wouldn’t break down in the environment, were toxic, and could cause serious health problems, including liver damage, reproductive and developmental defects and cancer.

More about health hazards and Dupont's cover up of health studies

• PFC Health Concerns, study, Environmental Working Group
• DuPont Hid Teflon Pollution For Decades, internal 3M documents
• Mortality among 3M workers at a perfluorooctanoic acid plant in Cottage Grove, MN, study, Environmental Working Group

Contamination is widespread

The most dangerous of the Teflon chemicals is known as C8 or PFOA (perfluorooctanic acid). A panel of independent scientists advising the Environmental Protection Agency declared this chemical a likely human carcinogen on June 28, 2005.

• Independent Science Panel to EPA: Teflon Chemical is 'Likely' Human Carcinogen, press release, Environmental Working Group

This chemical is used at DuPont’s plant on the Ohio River in Parkersburg, West Virginia. Tests show that Teflon chemicals contaminated air and drinking water supplies in West Virginia and Southeast Ohio near DuPont’s plant in Parkersburg, W. VA.

• Little Hocking Water Association
• 2005 update notice

Due to the widespread risks to human health and the environment, the original maker of Teflon chemicals, 3M, chose to stop making these chemicals in 2000. DuPont is now the only manufacturer in the US.