DuPont Hid Teflon Pollution For Decades

Secret tests conducted in 1984 by the DuPont chemical company found a Teflon-related contaminant (C8) in the tap water of the Little Hocking Water Association in Ohio, just across the river from the company’s Teflon plant in Parkersburg, West Virginia. But the company never told the community, its water utility or state regulators about the tap water testing program, which continued through at least 1989, or about the positive findings.

West Virginia Map

The existence of the Ohio tests for C8 (also known as PFOA) came to light through internal company documents obtained in court proceedings by lawyers representing several thousand Parkersburg area residents who have sued DuPont for polluting tap water on the other side of the river.

Today, tap water in Little Hocking is contaminated with C8 at levels exceeding four parts per billion, and the community’s water supplier has taken one of its four production wells offline because of high C8 levels. It is all but certain that Little Hocking rate payers have been drinking C8-tainted tap water for decades, but they only learned of it in January, 2002, after town officials, informed of contamination in the neighboring community of Lubeck, petitioned West Virginia’s Department of Environmental Protection to perform tests that detected the chemical.

DuPont evidently started a clandestine tap water surveillance program in Little Hocking in 1984, three years after company doctors found the same chemical in the blood of female plant workers. The company also tracked pregnancy outcomes of the women and soon transferred them out of the production facility. A company document from 1981, marked “PERSONAL & CONFIDENTIAL: C-8 BLOOD SAMPLING RESULTS” indicates that DuPont tested for and found C8 in the blood of eight women employees, and lists pregnancy outcomes for seven of them. Two of the seven children had birth defects. [View document]

In November 2002, the Environmental Working Group (EWG) published a critique of the safety limit for the Teflon-related chemical C8 in drinking water that was established through a committee led by the West Virginia Department of Environmental Protection (DEP), which included representatives from DuPont. Our review of the science showed that in a series of public briefings, the committee did not accurately represent what is known about C8 toxicity. We also found that in setting the safety limit the committee misinterpreted and misapplied standard procedures for establishing drinking water contaminant limits. (We describe the technical shortcomings of the committee’s work in a science policy memorandum from November 13, 2002.)

As EWG has continued our research on the toxicity and environmental occurrence of C8, we have found public documents showing that on numerous occasions over the past 22 years, DuPont failed to notify local communities of significant new findings about C8 pertinent to public health, including the discovery of C8 in Little Hocking’s drinking water coincident with studies that clearly raised DuPont’s concerns about C8 toxicity.

Secret Tests

DuPont internal documents show that the company detected C8 in the Little Hocking tap water in 1984. [View Document] According to water company officials, DuPont did not tell the water utility or the community of this finding at that time. Instead, the company conducted a series of subsequent tests that neither confirmed nor refuted the original findings. DuPont then dropped the investigation entirely.

Documents indicate that DuPont conducted tests for C8 in Little Hocking tap water six times between 1984 and 1989. At the time of the tests, DuPont had reason to be concerned about the hazards of drinking C8 in tap water. Internal company studies obtained from the U.S. EPA show that DuPont knew as early as 1980 that C8 was toxic, persistent, and that it presented health risks to exposed individuals. The extraordinary persistence of C8 should have been a sufficient reason for DuPont to inform Little Hocking of the contamination. At the time of the detection in Little Hocking water, the DuPont internal exposure standard for C8 in water was 1 part per billion. Today, C8 levels exceed four parts for billion in city tap water, and the utility has taken one of their four production wells offline.

For the most recent test results, visit


1980 — DuPont’s C8 supplier, 3M, published new data in the peer-reviewed literature showing that humans retain C8 in their bodies for years. The estimate 3M gave for the time needed for a person to clear just half of the accumulated C8 from the body, after all exposures cease, ranged up to 1.5 years. The vast majority of industrial chemicals, by contrast, clear the body in a matter of days. [View document]

April 1981 — DuPont tested for and found C8 in the blood of female plant workers in Parkersburg. The company followed and documented pregnancy outcomes in exposed workers. Two of seven children born to female plant workers between 1979 and 1981 had birth defects — one an “unconfirmed” eye and tear duct defect, and one a nostril and eye defect. [View document]

1981 — DuPont reassigned 50 women in its Parkersburg plant. For an account of the staff transfers, see veteran investigative reporter Jim Morris’ story at

1983-1984 — Beginning in 1983, DuPont’s C8 supplier, 3M, documented a trend of increasing levels of C8 in the bodies of 3M workers. 3M’s medical officer pointed out that unless the trends change, “we must view this present trend with serious concern. It is certainly possible that... exposure opportunities are providing a potential uptake of fluorochemicals that exceeds excretion capabilities of the body.” Through these 3M studies, the perfluorinated industry, including DuPont, was on alert that C8 was not only persistent in the human body but also has the capacity to build up to high levels in the body through repeated exposures. [View document]

March 1984 — In the wake of reassigning female plant workers, and the determination of C8’s persistence in the body, DuPont tested Little Hocking tap water for C8, and found it. [View document]

June 1984 — DuPont tested Little Hocking water again, and two separate documents reveal differing results: the first indicated that C8 was not detected; but the second indicated that C8 was found at the detection limit. According to documents obtained by EWG, three years passed before DuPont tested again, and in none of these instances was the community informed of the tests or the results. [View Document #1 | View Document #2]

March 1987, May 1988 — DuPont tested for C8 in Mason’s Village Market and the Ritenour home in Little Hocking, and did not find it above the test detection limit.
[March 1987: Excerpt | Full Document / May 1988: View Document]

November 1988 — DuPont tested for C8 in the Ritenour home in Little Hocking. The analysis report listed the result as: “contaminated sample, analysis not possible.” [View document]

May 1989 — DuPont tested again in the Ritenour home. The analysis report gave the result, again, as: “contaminated sample, analysis not possible.” EWG found no evidence that follow-up tests were conducted. [View document]

At no point during this five-year period of water testing did DuPont inform the community of the potential contamination of its water supply. Twelve years later, after learning of C8 contamination in tap water from the neighboring community of Lubeck, WV, Little Hocking Water Association officials petitioned WV DEP to test city water wells. Only then (January 2002) did the community learn of the contamination. [Read the Little Hocking news release -]

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