Hazard Assessment of Perfluorooctane Sulfonate (PFOS) and its Salts:
In 2000 several member countries agreed to informally work together to collect information on the environmental and human health hazards of perfluorooctane sulfonate (PFOS) to produce a hazard assessment. The decision followed the announcement by a major US manufacturer (3M) to globally phase out the manufacture and use of these chemicals beginning in 2001. The US and the UK agreed to lead the activity with the Secretariat assisting by requesting readily available exposure information from member countries as well as from non-member countries through IFCS and UNEP.
At the 31st Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pesticides and Biotechnology (7-10 November 2000), it was agreed that, since this was a matter of sufficient interest to all member countries, this activity should be undertaken under the Existing Chemicals Programme, overseen by the Task Force on Existing Chemicals. A special meeting on PFOS and its salts was held on 25 January 2001 in Orlando, USA, where the draft hazard assessment was discussed. The draft hazard assessment was revised twice since December 2000 to incorporate comments and input from member countries, as well as to incorporate newly completed studies.
At the 34th Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pesticides and Biotechnology (5-8 November 2002), the final draft of the assessment was endorsed. The Joint Meeting recommended that this document be derestricted and published under the authority of the Secretary General.
Perfluorooctane sulfonate (PFOS) is a candidate for further work.
Sufficient information exists to address hazard classification for all SIDS human health endpoints. PFOS is persistent, bioaccumulative and toxic to mammalian species. There are species differences in the elimination half-life of PFOS; the half-life is 100 days in rats, 200 days in monkeys, and years in humans. The toxicity profile of PFOS is similar among rats and monkeys. Repeated exposure results in hepatotoxicity and mortality; the dose-response curve is very steep for mortality. This occurs in animals of all ages, although the neonate may be more sensitive. In addition, a 2-year bioassay in rats has shown that exposure to PFOS results in hepatocellular adenomas and thyroid follicular cell adenomas; the hepatocellular adenomas do not appear to be related to peroxisome proliferation. Further work to elucidate the species differences in toxicokinetics and in the mode of action of PFOS will increase our ability to predict risk to humans. Epidemiologic studies have shown an association of PFOS exposure and the incidence of bladder cancer; further work is needed to understand this association.
Sufficient information exists to address hazard classification for all SIDS environmental endpoints. PFOS is persistent in the environment and has been shown to bioconcentrate in fish. It has been detected in a number of species of wildlife, including marine mammals. Its persistence, presence in the environment and bioaccumulation potential indicate cause for concern. It appears to be of low to moderate toxicity to aquatic organisms but there is evidence of high acute toxicity to honey bees. No information is available on effects on soil- and sediment-dwelling organisms and the equilibrium partitioning method may not be suitable for predicting PNECs for these compartments. PFOS has been detected in sediment downstream of a production site and in effluents and sludge from sewage treatment plants.
Given the apparent widespread occurrence of PFOS, national or regional exposure information gathering and risk assessment may need to be considered. In addition, data on its toxicity to soil and sediment-dwelling organisms could be generated as a post-SIDS activity. There is currently no information on effects on soil- or sediment-dwelling organsisms and PFOS has been detected in sediment and its presence in sewage sludge could lead to soil exposure if spread on agricultural land.
The full hazard assessment can be downloaded here: [PDF ]
This hazard assessment of perfluorooctane sulfonate (PFOS) and its salts includes all information that was available by July 2002.
The hazard information on PFOS should be used with caution in evaluating the potential hazards of other perfluorinated compounds. The perfluorinated compounds represent a very unique chemistry whose toxicological properties are presently not well understood and clearly the presence of different length (perfluorinated) carbon chains and functional groups are likely to influence toxicity. It is not clear at this time whether the hazard concerns of PFOS can be extrapolated to other perfluorinated compounds except under circumstances where the compound may degrade to PFOS.
At the 34th Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pesticides and Biotechnology (5-8 November 2002), Italy, Japan, Switzerland and the UK agreed to contact the PFOS manufacturers in their countries to determine whether these companies have plans to phase out PFOS production and to report the results to the 35th Joint Meeting in June 2003. Furthermore, member countries agreed to report to the Joint Meeting every two years on new PFOS-related information concerning production, use and exposure, along with new information on routes of exposure.
In 2004, a questionnaire on the production and use of Perfluorooctane sulfonate (PFOS), Perfluoroalkyl sulfonate (PFAS), Perfluorooctanoic acid (PFOA), related substances and products/mixtures containing these substances has been circulated to countries. The OECD has also set-up an electronic discussion group for Perfluorooctane sulfonate (PFOS) and PFOS-related chemicals. For further assistance about the questionnaire and the discussion group, please contact: EHS.Contact@oecd.org.
Risk Reduction Strategy and Analysis of Advantages and Drawbacks for Perfluorooctane Sulphonate (PFOS)
The UK risk reduction strategy document for Perfluorooctane Sulphonate (PFOS) has now been published and is available via this link to the UK's Department for Environment, Food & Rural Affairs Chemicals web site.
This document presents the results of the survey of production and use information on Perfluorooctane Sulfonate (PFOS), Perfluoroalkyl Sulfonate (PFAS), Perfluorooctanoic Acid (PFOA), related substances and products/mixtures containing these substances.
Preliminary lists of PFOs, PFAs, PFOA and related compounds and chemicals that may degrade to PFCA
This document provides preliminary lists of PFOs, PFAs, PFOA and related compounds and chemicals that may degrade to PFCA to assist the 2006 survey of the production and use of these substances.
Results of the 2006 OECD Survey on Production and Use Of PFOS, PFAS, PFOA, PFCA, Their Related Substances and Products/Mixtures Containing These Substances
This document presents the results of the 2006 survey on manufacture and use of Perfluorooctane Sulfonate (PFOS), Perfluoroalkyl Sulfonate (PFAS), Perfluorooctanoic Acid (PFOA), Perfluorocarboxylic acid (PFCA), their related substances and products/mixtures containing these substances.
PFCs: Outcome of the 2009 survey
Survey on the production, use and release of PFOS, PFAS, PFOA PFCA, their related substances and products/mixtures containing these substances
This document presents the results of the 2009 survey on manufacture and use of Perfluorooctane Sulfonate (PFOS), Perfluoroalkyl Sulfonate (PFAS), Perfluorooctanoic Acid (PFOA), Perfluorocarboxylic acid (PFCA), their related substances and products/mixtures containing these substances.
Report of an OECD Workshop on Perfluorocarboxylic Acids (PFCAs) and Precursors
This publication provides the outcome of an OECD Workshop on Perfluorocarboxylic acids and Precursors, hosted by Sweden in November 2006. It highlights ongoing PFC-related activities in OECD countries, indentifies gaps in knowledge, reveals existing concerns and how these could be mitigated. Recommendations of future activities within OECD, governments, industry, academia and NGOs are also identified.