Two recent studies have highlighted high levels of perfluoroalkyl substances (PFAS) in consumer products and food contact materials. They are likely to be a significant source of global human exposure to these persistent and potentially toxic compounds.
The first paper measured the levels of perfluorinated carboxylic acids (PFCAs), perfluorinated sulfonic acids (PFSAs) and fluorotelomer alcohols (FTOHs) in household products, purchased in Germany in 2010.
The study was published in Environmental Science and Pollution Research by five scientists from the Fraunhofer Institute.
Some 115 samples of items, such as outdoor clothing, carpets, cleaning products, leather goods, baking or greaseproof paper and ski waxes were analysed.
Very high levels of PFCAs and PFSAs were found in ski waxes (in the ppm range) and in outdoor textiles (35 and 41ppb for perfluorooctanoic acid (PFOA) and perfluorooctanyl sulphonic acid (PFOS) respectively).
High levels of PFCAs were also found in old (pre-2010) samples of baking papers, which contained up to 658ppb of PFOA. More recent samples contained lower levels but most had PFCAs or PFSAs at, or above, 1ppb, particularly perfluoropentanoic acid (PFPA).
The scientists also found that 100% of outdoor clothing, 83% of carpets and 73% of leather goods analysed breached the EU Regulation on persistent organic pollutants (POPs), by containing PFOS levels in excess of 1 microgram per square metre. These items also contained other unregulated PFSAs and PFCAs at similar and higher levels.
FTOHs were found, at the highest levels, in protective sprays (up to 719ppb), cleaning products (up to 73ppm), outdoor textiles (up to 380μg/m2), gloves and carpets.
The scientists conclude: “This study proves the importance of screening and monitoring of consumer products for PFAS, and the necessity for an action to regulate the use of PFAS, especially PFOA.”
They emphasise potentially high child exposure from hand-to-mouth contact with textiles, carpets and gloves, and adult exposure through the use of protective sprays and cleaning products in confined spaces.
The European Commission has promised to back a global ban on PFOA and its compounds, by adding it to the UN Stockholm Convention on POPs. Although supported by manufacturers’ group, the Fluoro Council, the electronics sector believes such a ban would effectively extend to all fluoropolymers.
The second study analysed food contact materials (FCMs) from China and the US, for FTOHs. It was published in Environmental Science and Technology by four scientists at Peking University.
A particular focus was Chinese paper food wrapping. This is widely used, following a national ban on expanded polystyrene alternatives in 1999, due to concerns over litter and migration of monomers into food.
The study found that four newly identified long-chain FTOHs were present in many Chinese products: 12:2 FTOH, 14:2 FTOH, 16:2 FTOH and 18:2 FTOH.
The dominant FTOH in these products was 10:2 FTOH.
Another group of products contained mainly 8:2 FTOH, with some longer-chain forms. A third group, which included all products sourced from the US, contained mainly 6:2 FTOH, reflecting the shift in western markets to short-chain PFAS.
The scientists conclude that the discovery of the long-chain FTOHs, in Chinese products, may explain the “increasing temporal trends in long-chain PFCAs” in human serum in North America, Europe and East Asia.
They also measured PFCAs in Chinese paper food wrappers and migration rates into food simulants. Migration of FTOHs was generally less than for PFCAs, but for both groups of compounds, short-chain compounds were significantly more mobile than longer-chain alternatives.
The US Food and Drugs Administration recently banned three classes of PFASs in FCMs.
Denmark has instituted a national ban on PFAS in paper and cardboard FCMs, and has asked the European Commission for action at EU level.