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More environmentally friendly alternatives to PFOS-compounds and PFOA

2 Introduction

2.1 The purpose of the project

A survey of perfluorooctanyl sulfonate (PFOS) and PFOS-related compounds in consumer products carried out by the Danish EPA in 2001 and 2002 has revealed that PFOS-related compounds are used in numerous products, and that several PFOS-related compounds are used in products in Denmark (Havelund 2002).

Therefore, The Danish EPA initiated a survey that should map the use of PFOS-related compounds in impregnating agents, wax and floor polish products (Vejrup et al. 2002). Furthermore, the Danish EPA has initiated a survey that will map the use of compounds in shoe care products, and hereby also the use of PFOS-related compounds. The common purpose of these projects is to map the dissemination of these problematic PFOS-related compounds.

The purpose of this present project is to collect know-how about the existing technical alternatives to PFOS/PFOS-related compounds and perfluorooctanoic acid (PFOA)/PFOA-related compounds.

Finally, the purpose of this project is to carry out an environmental and health assessment of PFOS-related substances and of the possible alternatives to PFOS- and PFOA-related compounds.

2.2 History

This is a short summary of the most important aspects in the history of fluorinated chemicals. If not otherwise described, the information is from the website of the Fluoride Action Network (Fluoriede Action Network 2004).

The history of fluorinated chemistry starts in 1938, when the fluoropolymer PTFE (polytetrafluoroethylene) was discovered by the company DuPont and later introduced to the market in 1949. In 1951 ammonium perfluorooctanoate, the ammonium salt of PFOA (also called C8) starts to be used to make PTFE and related polymers.

In 1954 France's Conseil Supérieur de l'Hygiène Publique officially cleared PTFE for use on frying pans by the company TEFAL. In 1958 the French ministry of agriculture approved the use of PTFE in food processing (Funderburg 2000).

In 1962 the American Food and Drug Administration (FDA) grants a final approval to PTFE cookware. In 1967 the FDA approves Zonyl®, DuPont's leading brand of fluorinated telomers, for use in food packaging.

Already in 1954 some employees at DuPont started to express concerns about the toxicity of C8. In 1978, 3M reported that C8 was detected in the blood of its workers, and DuPont began to express concern internally about the possible toxic effects of C8.

3M and DuPont obtained further knowledge about C8 in the early 1980's:

  • Rats fed with fluorinated telomers metabolise them into PFOA.
  • Suspicion that PFOA causes eye defects in rats but this has never been confirmed.
  • Two babies are born with eye-related birth defects. Their mothers, employees at DuPont, had PFOA detected in their blood. However, a connection was not established.
  • Other studies showed no link between PFOA and birth defects.
  • PFOA was found in local drinking water.

In May 2000 3M announced, under pressure from the U.S. EPA, that they will begin phasing out PFOS and US production of a related chemical (PFOA) due to principles of responsible environmental management.

In September 2002 the U.S. EPA began the review of data that are produced to understand the hazards and risks associated with the use of PFOA. Animal studies showed that exposure to C8 could result in a variety of effects including developmental/reproductive toxicity, liver toxicity and cancer.

In June 2003, the 3M Company replaced PFOS in their Scotchgard brand with a C4 chemical (PFBS – perfluorobutanesulfonate).

In February 2004 the U.S. Federal Agency (NIEHS) announced that they would conduct a four-year study of blood levels of residents in the affected Ohio communities. Furthermore, the U.S. Federal Housing and Urban Development (HUD) Agency announced in March 2004 that they would conduct a two-year study of young children's exposures in their Florida homes to selected chemicals (pesticides) including polyfluorinated chemicals.

In April 2004 DuPont launched a $1 million study to compare the health of employees, who work directly with C8, and those who do not. According to DuPont the objective of the study includes multiple health endpoints. The study will also evaluate liver function, the prime target of PFOA as observed in animal studies (Personal communication, DuPont 2004a).

In June 2004, the US EPA announced that they would conduct a study of how PFOA gets into human blood (EWG, 2004a). The study will also include degradation studies of telomers. The goal of the degradation studies is to determine whether PFOA comes from the breakdown of telomers' carbon chains or from impurities in telomer products (Hogue, 2004).

In July 2004 the US EPA Enforcement Division files a complaint against DuPont, as the US EPA alleges that DuPont has failed to report information about the hazards of C8.

In August 2004 DuPont responded to EPA's complaint providing facts and information that refute the allegations made by the agency (DuPont website 2004).

2.3 The PFOS/PFOA problem

Polyfluorinated substances are generally persistent in the environment. Carbon-fluorine bonds are extremely strong, and as a result they do not break easily. The problem with different perfluorochemiclas, including a large number of PFOS-related compounds and PFOA-compounds, is that the chemicals may degrade in the environment to PFOS and PFOA respectively, but no further degradation of PFOS or PFOA will occur, as they are chemically and biologically inert and very stable. Furthermore, PFOS, PFOA and related substances are found to bioaccumulate in wildlife and in humans.

Recent observations show that PFOS, PFOA and related substances have been found in mammals, birds and fish in large part of the world, including polar bears in the Arctic (Giesy & Kannan 2001; Giesy & Kannan 2002). Furthermore, both PFOS and PFOA have been observed in blood samples of the general population in USA, India and Italy (Kannan et al. 2003).

The growing concern of PFAS and derivatives is due to the fact that these compounds are globally distributed in the environment, are environmentally persistent, are bioaccumulative, are magnifying in food chains and are potentially harmful for animals and Man (OECD 2002; Giesy & Kannan 2001).

OSPAR [1] decided to add PFOS to the OSPAR list of chemicals for priority action (OSPAR HSC 2003), whereas PFOA was not added to any OSPAR list at that stage on the basis of the data provided by industry (APME 2002). This decision will be revisited in the near future, as the full dataset is now available from the further testing programme on PFOA (APME 2004).

The pathways of PFOS and PFOA to remote locations as the Arctic are virtually unknown. In comparison with the typical persistent organic pollutants (POPs) some PFOS and PFOA related substances are much more water-soluble and a little more volatile.

Recent studies suggest that fluorotelomer alcohols, which are volatile and more readily can be transported to remote locations, can be degraded to PFOA in the environment, and hence explain the discovery of PFOA in remote locations (US EPA 2003b; Renner 2004; Ellis et al. 2004). Other potential sources of PFOS and PFOA are the direct use of fire-fighting foams in the Arctic, and a recent hypothesis is that via ocean currents direct long-range transport of PFOS and PFOA may occur to the Arctic (Taniyasu, 2004).

A discussion is ongoing at the moment, whether the occurrence of PFOA in the environment isdue to:

  • Use of PFOA-based products, including AFFF agents,
  • The residual from POSF-based products,
  • Degradation of telomer alcohols in the environment,
  • Other impurities in telomer-based polymeric products, ordirect emissions/releases of PFOA to the environment during fluoropolymer manufacture and processing.

Future research will address this in more details.

2.4 Method used

This project is primarily based on a literature study and on easily accessible information on the Internet. This information has though, where relevant, been supplemented with more specific information as searches in the Danish Product Register on specific compounds and contact to relevant producers and suppliers of products containing PFOS-related compounds or PFOA-compounds.

The more specific initiatives taken in order to search for alternatives to PFOS-related compounds are described in details in Appendix B. In brief, an Internet search has been performed and the relevant producers have been contacted by email. Furthermore, relevant Danish importers of products containing PFOS- or PFOA-related compounds have been contacted in order to learn more about the use and possible alternatives (see Appendix D and E).

With regard to the environment and health assessment of the PFOS-related compounds and PFOA, a detailed literature study has been performed. By personal contact to Professor John P. Giesy (Zoology Department at Michigan State University) and Professor Scott A. Mabury (Department of Chemistry at the University of Toronto) – some of the leading scientists in this area - it was possible to get access to the newest possible information about the subject.

Furthermore, representatives for DuPont has been helpful and provided useful information for this project.

Footnotes

[1] OSPAR is the current instrument guiding international cooperation on the protection of the marine environment of the North-East Atlantic.

 

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Version 1.0 June 2005, © Danish Environmental Protection Agency