PFOS, Perfluorooctane Sulfonate

Transcription

1 PFOS, Perfluorooctane Sulfonate For nomination to UN- ECE LRTAP Protocol on POPs Niklas Johansson, Swedish EPA

2 PFOS, Perfluorooctane Sulfonate as its potassium salt

3 From the Original PFOS dossier Criterion Potential for LRAT Toxicity Persistence Bioaccumulation Criterion met? Yes Yes Yes Yes Remark Vapour pressure = 3,31 x 10-4 Pa Atmospheric half life > 2 days (estimated value based on photolytic half life > 3,7 years) Sub-chronic exposure: Mortality in monkeys at 4,5 mg/kg b.w./day. Reproductive toxicity: mortality in pups at 1,6 mg/kg b.w./day. Acute toxicity to fish: LC 50 = 4,7 mg/l Extremely persistent. No degradation recorded in chemical or biological tests Found in highly elevated concentrations in top predators. Calculated hypothetical BMF = BCF in fish =

4 PFOS update Sweden has presented an update of the scientific literature (Addendum to the PFOS dossier) Sweden has presented an overview of existing information on PFOS production, use, emission and pathways to the environment and cost/benefits with alternatives/substitutes

5 PFOS, Perfluorooctane Sulfonate Addendum to initial dossier presented in October 2005 Some 80 studies presented June 2004 October 2005 and studies previously overlooked, These studies support the previous conclusions in the PFOS dossier that PFOS meets all the POPcriteria. PFOS does not formally fulfill the BCFcriteria, but new studies present further evidence of bioaccumulation

6 Addendum, PFOS and Bioaccumulation all monitoring data published show that PFOS bioaccumulates in the food webs. However, because of the unusual physical-chemical characteristics of this substance, the mechanism of bioaccumulation seem to be different from other POPs. PFOS does not follow the classical pattern of partitioning into fatty tissues, but does instead bind preferentially to proteins in the plasma, such as albumin and β-lipoproteins, and in the liver, fatty acid binding protein (L-FABP).

7 Addendum, PFOS and Bioaccumulation at what concentrations of PFOS will the binding sites on these proteins will be saturated? In fish, PFOS in water and plasma followed an almost linear relationship in the doses up to 0,3 mg/l without any signs of saturation This is far above environmentally relevant levels. BCF in whole fish determined to 2800 at a concentration of 86 µg/l No similar data from mammals. Considering the their high level of bioaccumulation and the high protein content, saturation of binding sites is not likely to limit the bioaccumulation of PFOS in mammals either.

8 Addendum, PFOS and Bioaccumulation Whole body-bcf for round gobies was calculated to approximately In bald eagles, the mean PFOS concentration in the livers, 400 ng/g w.w, gives a BMF of four to five when compared to fish at higher trophic levels. For mink, BMFs from 145 to 4000 were calculated based on the mean liver concentration, 18 µg/g w.w, compared to concentration in their prey In conclusion, the new data supports that PFOS fulfills all POP-criteria, including the bioaccumulation criteria.

9 Overview of Existing Information on PFOS Production, Use, Emission and Pathways to the Environment and Cost/Benefits with Alternatives/Substitutes Estimated current European demand (kg/year): Photographic industry 1,000 Semiconductor industry 470 Hydraulic fluids 730 Metal plating 10,000

10 Overview of Existing Information on PFOS Production, Use, Emission and Pathways to the Environment and Cost/Benefits with Alternatives/Substitutes Emissions and pathways: Releases of PFOS (and its related substances) occur during their whole life cycle Relative contribution from different pathways unclear Wastewater treatment plants might be of general importance as well as certain applications on fabric The absolute persistency calls for a different approach to calculate the emission scenarios for PFOS today and in the future

11 Overview of Existing Information on PFOS Production, Use, Emission and Pathways to the Environment and Cost/Benefits with Alternatives/Substitutes Alternatives/Substitutes Cost/Benefits Historic uses Remaining uses Legislative Controls Notifications to the EU Commission from UK and Sweden concerning proposed restrictions on marketing and use of PFOS and 96 identified derivatives The EU commission has also proposed a ban on marketing and use on PFOS (The proposed Directive would cover the great part of the exposure risks by preventing the use of PFOS in carpets, textiles, upholstery, leather, apparel, paper, packaging and other applications. These uses seem already to be phased out and the proposal would prevent their reintroduction)

12 Future activities Sweden will investigate the possibilities to carry out an extended Cost/Benefit analysis, further study the possibilities to link monitoring data to possible sources or other emission sites. Both studies to be ready by end of March 2006, Sweden will coordinate its activities with EU s PBT-group and also consider the position of the EU Commission in preparation for the meeting in Tallinn in May 2006.