PFAS in fats, oils and by-products - Analytical challenges and first results

PFAS is an abbreviation for per- and polyfluorinated chemicals and belongs to the group of Persistent Organic Pollutants (POPs). According to the latest estimates, this group of substances comprises more than 10,000 different substances. PFAS do not occur naturally and have only been produced since the late 1940s. Chemically speaking, the organic compounds consist of carbon chains of various lengths in which the hydrogen atoms are completely (perfluorinated) or partially (polyfluorinated) replaced by fluorine atoms. Perfluorinated carbonic and sulfonic acids and their precursor compounds, which can be degraded to these persistent perfluorinated substances, are used most frequently.  PFAS are water, fat, and dirt repellent as well as chemically and thermally stable. Due to these properties, they are used in numerous consumer products such as cosmetics, cookware, paper coatings and textiles. PFAS are also used for the surface treatment of metals and plastics, in pesticides and fire extinguishing agents.

The PFAS in general and especially some specific isomers have been declared to substances of concern. In Europe and North America, there are several regulatory initiatives to get more information about PFAS and to set maximum limits for food and feed products resp. to extend the existing European limits which are already in force for meat and fish products. As PFAS are ubiquitous and should be analysed in the part per trillion range, the analytical procedure for the analysis is challenging.

First results are presented for the occurrence of PFAS in selected fats, oils, and its industrial by-products with a focus on the specific substances perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS).