PFAS pesticides – what is that?
Over the last few months articles in traditional and social media have highlighted the presence of so called PFAS pesticides. This has concerned the number of such pesticides, their rapidly increased use in the EU and the fact that residues are found in fruits and vegetables.
In Nov 2023 a report was published by PAN (Pesticide action network Europe) assessing authorization and sales of PFAS pesticides stating that 37 active substances in use in the EU are defined as PFAS. This report was followed up in Feb 2024 by an investigation of the occurrence of PFAS pesticides in fruit and vegetables across the EU with data taken from national monitoring programs between 2011-21. This study showed that in 2021 pesticides classified as PFAS could be found in 20% of EU-grown fruit/berries and 12% of vegetables. However, MRL (max residue levels) values were not typically exceeded. Among the EU produce with 30% or more detects strawberries, peach, apricot and cucumber can be mentioned. Corresponding numbers for import to the EU were 18% (fruit) and 12% (vegetables). The ten most common pesticides identified are listed in the table below.
According to PAN the approval, use and residues found are all of concern in a number of ways. In terms of risk assessment it is claimed that PFAS properties of the pesticides and their metabolites are not fully addressed, and that the same applies to any cocktail effect and persistence of the molecules incl degradation products. From this reasoning it is also concluded that it can not be justified that pesticides are left out from the general PFAS restriction proposed by ECHA.
Table: The ten most frequently detected PFAS pesticides in fruit and vegetables according to PAN (2024) incl year for most recent risk assessment. Additional information from Wikipedia and PubChem
Typically the PFAS moiety (acc to OECD definition) of the molecules is a trifluoromethyl (-CF3) group (in one case -CF2-), attached to a C or O atom. Addition of such a group improves stability of the molecule (PAN, 2024) but in the case of C-CF3 the moiety can cause formation of trifluoroacetic acid (TFA) at degradation (UBA, 2021). Theoretical calculations by UBA (2021; German EPA) indicate that inputs at decomposition of pesticides can be a major TFA source and this includes most of the compounds in the table. In addition, especially Fluazinam can be of quantitative importance for TFA formation. The reasoning is supported by high levels in surface waters in agricultural areas (up to 7-10 µg/l; Freeling and Björnsdotter, 2023) in Germany often coinciding with pesticides or other metabolites. A Eurofins study on Norwegian and Swedish drinking waters revealed the presence of TFA in all samples investigated (n=32; 70-720 ng/l). Guideline values for TFA in drinking water already exist in Germany, Denmark and The Netherlands and the substance may be included in the “PFAS total” parameter in the drinking water directive (DWD).
In the US pesticides and PFAS have been associated in other ways. Recent discussions have focused on leaching of PFAS from containers, in particular PFCA (PFBA to PFUdA), made of fluorinated HDPE plastic. The presence of these compounds in a number of fluoro-treated containers has been confirmed by US-EPA. In parallel the presence of PFOS in some pesticide products have been brought to attention, but these findings have not been possible to confirm by US-EPA.
Eurofins offers a wide range of both PFAS and pesticides in food and environmental matrices. For example, there is a number of pesticide multi screening packs for various foodstuffs which include many of the substances mentioned above. PFAS can be determined in most matrices such as food and water. Ultrashort PFAS incl TFA are offered for water. Read more on our PFAS homepage.
Welcome to contact us if you have any questions about pesticides and/or PFAS
References and links
Eurofins PFAS homepage
Freeling and Björnsdotter (2023; TFA review; free abstract)
PAN Europe (2023)
PAN Europe (2024)
UBA (2021)
US-EPA