"Eternal chemicals": practical but toxic

The long-lived and toxic substance group of PFAS should be replaced by flour-free alternatives

06-Apr-2023 - Germany

They are known as "eternal chemicals" because they are extremely long-lived and cannot be broken down naturally: perfluorinated and polyfluorinated alkyl substances (PFAS). This is a major problem, because these substances are toxic to humans and the environment - and they are now found almost everywhere. Prof. Dr. Hubertus Brunn and five co-authors have examined the effects of this group of substances, which includes almost 10,000 substances, in a review that has now been published in the scientific journal "Environmental Sciences Europe". Prof. Brunn teaches food and environmental toxicology at Justus Liebig University Giessen (JLU) and is former director of the Hessian State Laboratory in Giessen.

"Some PFAS are known to be chronically toxic at even low concentrations; for example, they damage the immune system and thyroid function," says Prof. Brunn, first author of the review. "They also promote the development of cancer in humans." Humans, as the last link in numerous food chains, are exposed to PFAS intake primarily through food and drinking water. Exposure estimates and biomonitoring in humans show that the tolerable weekly dose established by the European Food Safety Authority (EFSA) in 2020 for four specific PFAS of 4.4 nanograms per kilogram of body weight is frequently reached and in many cases exceeded.

That PFASs are so widespread - they are detected even in remote regions of the world - is due to their highly practical properties. For example, they are not only water-repellent, but also oil- and dirt-repellent. That's why they are used in tens of thousands of products. Outdoor textiles, food packaging, foam extinguishing agents, lubricants, carpets, ski waxes and furniture are just a small selection.

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Once released, these substances cannot be recaptured and are virtually impossible to destroy. Even when burned, very high temperatures are required for these compounds to completely decompose. This is due to the very stable bond between the carbon and fluorine atoms. Thus, PFASs remain in the environment and food chains for years to decades, where they accumulate. Processes for soil and groundwater purification and drinking water treatment are extremely difficult and often ineffective because these substances are difficult to remove from water and soil. The recycling of products containing PFAS, such as paper and food packaging, also leads to carryover of the pollutants.

To prevent further contamination of the environment, food chains and humans, five European countries - Norway, Sweden, Denmark, the Netherlands and Germany - submitted a proposal to the "European Chemical Agency" (ECHA) on January 13, 2023 to restrict the production, distribution and use of PFAS. It aims to reduce PFAS emissions to the environment and make products and processes safer.

Some PFASs have already been regulated internationally. As a result, many manufacturers as well as users have switched to other PFAS, especially short-chain representatives, which are particularly mobile in soil and water and often have not been well studied. Thus, short-chain PFAS are increasingly detected in food, human blood and the environment. Trifluoroacetic acid (TFA), among others, is present in rapidly increasing concentrations worldwide.

"Substituting individual PFASs classified as hazardous with other potentially equally hazardous PFASs with virtually unknown chronic toxicity can therefore not be a solution," said Prof. Brunn. "The only answer is to switch to fluorine-free alternatives for all applications where PFAS are not essential."

Also challenging is analytics: Since some of these substances show harmful biological effects even at very low concentrations, chemical analysis faces the task of developing methods for very sensitive detection of as many PFAS as possible.

Note: This article has been translated using a computer system without human intervention. LUMITOS offers these automatic translations to present a wider range of current news. Since this article has been translated with automatic translation, it is possible that it contains errors in vocabulary, syntax or grammar. The original article in German can be found here.

Original publication

Brunn, H., Arnold, G., Körner, W. et al. PFAS: forever chemicals – persistent, bioaccumulative and mobile. Reviewing the status and the need for their phase out and remediation of contaminated sites. Environ Sci Eur 35, 20 (2023)

https://www.chemeurope.com/en/news/1180087/eternal-chemicals-practical-but-toxic.html