Per- and polyfluorinated alkyl substances (PFAS) are increasingly in the spotlight

The EFSA publishes a new group TWI

Dec 2020. Per- and polyfluorinated alkyl compounds (PFAS), which also include PFOS (perfluorooctane sulfonic acid) and PFOA (perfluorooctanoic acid), are persistent organic pollutants (POP) that can affect humans through the food chain. This class of pollutants has been in focus of the European Food Safety Authority (EFSA) for several years. Now the EFSA has published a new group TWI for further compounds of this group of persistent organic pollutants (POPs).

Significant reduction of the toxicological base of operations in food law

In 2018, EFSA has set separate tolerable weekly intake levels (TWIs) for PFOS and PFOA (see Eurofins news European Food Safety Authority: focus on environmental contaminants). Meanwhile, EFSA has re-evaluated these substances considering more recent scientific knowledge and has followed its recent guidance for assessing combined exposure to multiple chemicals. With EFSA's current opinion, a group TWI for four selected PFAS compounds has now been published, which is well below the data published by EFSA in 2018. Thus, the toxicological base of operation in food law was significantly lowered:

bw = body weight, TDI = tolerable daily intake, TWI = tolerable weekly intake, RfD = reference dose, p = provisional

EFSA's current opinion took into account 27 different substances of the PFAS pollutant class. Based on observations in animals and humans, EFSA's toxicological analysis has ultimately focused on 4 PFAS compounds, as they currently contribute to PFAS body burden in humans:

• Perfluorooctane sulfonic acid (PFOS)
• Perfluorooctanoic acid (PFOA)
• Perfluorononanoic acid (PFNA)
• Perfluorohexane sulfonic acid (PFHxS)

Short-chain PFAS such as PFBA, PFBS and PFHxA, which contribute to the body burden but contribute less to bioaccumulation due to short half-lives in the human body, were not taken into account. Also long-chain PFAS compounds such as PFDA, which have longer half-lives but contribute to significantly lower proportions to the total body burden, were not taken into account.

Eurofins improves its analytical method for PFAS in food

EFSA once again highlighted the need for more sensitive analytical methods for PFAS in food in its opinion of 2020. The competence center for Dioxins & Persistent Organic Pollutants (POPs) within the Eurofins network of laboratories – Eurofins GfA Lab Service GmbH – keeps a close look on developments with regard to environmental contaminants and is already working on improving existing analytical methods for determination of PFAS. For example, we have recently been able to improve the limits of quantification of PFAS in food and feed. Following EFSA's current developments, the scope of reported results was amended by the sum of the four PFAs (PFOS, PFOA, PFNA and PFHxS) that are particularly in focus at EFSA.

Consultance and analytical services by Eurofins' experts

Do you have any questions regarding persistent organic pollutants (POPs) like PFAS or our analytical methods? For further questions do not hesitate to turn to your personal account manager or contact our experts directly.