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PFOA/PFOS Chemicals— A Timeline of Scientific Studies Outlining C-8 Risks to Human Health and the Environment

Perfluorooctanesulfonic acid (PFOA’s) and Perfluorooctanesulfonic acid are human-made chemicals commonly used by companies such as DuPont and 3M in products such as food wrappers, non-stick cookware, and fire-fighting foam.

Although there is an abundance of research available showing the potentially long-term impacts of these chemicals on the environment and human health, they continue to go unregulated. Most of the research which warn of the dangers of PFOA chemicals was produced by the companies DuPont and 3M, and was not made public until recently.

1961: DuPont’s toxicologist summarizes the toxicity and dangers associated with the chemical surfactants. His study determined that PFOA chemicals were positively associated with liver enlargement in rabbits and rats.

1963: 3M’s Technical Information manual covering Fluorochemical surfactants deems PFAS as toxic.

1965: DuPont sponsors a 90-day feeding study on rats that finds a positive association between the material being studied and increased liver, kidney, and spleen size. The material studied is omitted from public view, but it is suspected by Environmental Working Group to be PFOA or PFOS.

1966: DuPont petitions to use PFAS chemicals as a food additive, despite the recent evidence of their toxicity. The FDA rejects the petition, citing the 90-day feeding study in 1965.

1970: 3M warns the National Fire Protection Association’s magazine that PFAS is toxic to fish. DuPont scientists also release a statement that PFAS is “highly toxic when inhaled.”

1973: DuPont does a study to determine the effects of a new food-additive product named “Zonyl” in rats and dogs. Zonyl contained PFAS chemicals. When given the intermediate and highest dietary levels of Zonyl the rats and dogs had heavier larger organs and damaged livers.

1975: 3M is informed by a professor at University of Florida College of Medicine that PFAS (fluorocarbon carboxylic acids) build up in human plasma. . DuPont sent a warning letter to 3M expressing their concern about the toxic effects of Teflon K (containing PFAS chemicals) on their 10-day study on rats fed 25% Teflon K.

1977: A study is conducted to determine the amounts of chemicals in human blood. The document includes a chronology report which includes several small research studies done by 3M on workers and animals. In 1976, Central Research analytical developed an accurate method for determining the parts per billion quantities of organic fluorine compounds in human blood. Some of the findings included

- four laboratory personnel have blood samples analyzed. Concentrations of organic fluorine compounds in some personnel 100 times normal. (April 4, 1976).

- some Chemolite personnel show organic fluorine compounds at 1,000 times normal levels. (June 29, 1976).

- Cordova personnel exposed to fluoro-chemicals have up to 50 times normal values. (August 23, 1976).

- Mice fed “Scotchban” had 4,000 times normal organic fluorine compounds. (September 9, 1976).

1978: 3M conducts a 90-day oral study in rhesus monkeys of the fluorochemical FC-143. They were given doses between 0 and 100 mg/kg/day. The monkeys treated with the highest dose (100mg/kg/day) all died during weeks 2-5 of the study. At the 30mg dosage level, 3 monkeys died between weeks 7-12. They all showed signs of toxicity in the gastrointestinal tract. Tests find lesions on spleen, lymph nodes, and bone marrow. 3M discusses the results of the monkey study and determines PFOS and PFOA “should be regarded as toxic.”

1979: DuPont conducts a liver-function survey and coronary heart disease mortality study, and the researchers determine that C-8 (PFOA) exposed workers may have positive liver function tests more often than unexposed workers.

1981: 3M reassigns 25 workers of child-bearing potential to reduce their exposure to a type of fluorochemical that can cause birth defects in rats. The study showed that the fluorochemicals affected eye development in the fetuses of rats. . Dupont tells employees that they are excluding female employees of child-bearing capability from areas with potential for exposure to C-8.

1983: 3M notes PFAS’ potential harm to the immune system and recommends further studies.

1984: 3M tests organic fluorine levels in Chemolite workers’ blood and determines that they are rising. Dupont detects PFAS in the tap water in Little Hocking, Ohio. There is no record of Dupont alerting the local water utility.

1987: 3M PFOA animal study finds tumors in testes “not within normal biological variation.”

1989: 3M study finds elevated rates of prostatic cancer in employees.

1990: 3M study states risk of testicular cancer from exposure to C-8 (PFOA).

1992: Dupont obtains results from surveillance data mortality and cancer incidence study. There was a significant excess of cancers of the buccal cavity, pharynx, kidney, and urinary tract among male workers. It also shows a significant elevation in leukemia in male workers. . Former 3M scientist finds male PFOA workers more likely to die from prostate cancer.

1995: DuPont scientist requests a corporate policy on monitoring C-8 blood levels in employees due to concern about their long biological half-lives and human health effects.

1997:DuPont study finds heightened cancer rates among workers at Parkersburg Plant.

1998: 3M scientists report risk of ecological harm due to the presence of PFOS in the environment. The risk analysis finds that there is a significant risk of harm, and that it can move through the food chain. . 3M provides evidence to the EPA that PFAS accumulates in blood. . 3M animal study finds liver damage from PFAS exposure. .