Analysis of PFAS in firefighting foam

Per- and polyfluorinated chemicals (PFAS) are a large class that may include more than 15,000 compounds. Over the last 25 years, environmental and health effects caused by PFAS exposure have become a great concern. PFAS have many uses, with firefighting foam (AFFF = Aqueous Film Forming Foam) being one of the more common. All activities may give rise to environmental pollution of soil, water, and other matrices. AFFF used at firefighting training sites and during fire suppression is very likely the most frequent source. Legislation affecting PFAS in AFFF is expanding, and the EU POP (PFOS, PFOA, PFHxS) and REACH regulations (e.g., PFHxA, C9-C14 PFCA), in addition to the proposed general PFAS restriction for AFFF, can be mentioned as examples.

The PFAS composition of AFFF can vary substantially. Historically, AFFF has contained legacy compounds such as PFOS, PFHxS, and PFOA, but also so-called precursors to these substances. However, modern foams contain more advanced molecules. Studies have shown (e.g., KEMI PM 6/15) that current products are typically based on 6:2 telomer structures. One of these substances (which is also a precursor), and which has recently drawn a lot of attention, is 6:2 FTAB; however, there are others (e.g., DPOSA, 6:2 FTSAS).

TOP (Total Oxidizable Precursors) is a method used to chemically oxidize precursors to the corresponding perfluorinated carboxylic acids (PFCA). TOP can provide information on the types of precursors in the sample as well as an overall quantitative estimate. This information can be valuable when evaluating so-called “related substances” according to the POP and REACH regulations.

Eurofins (SE) has been analyzing AFFF since 2017, using both standard target analysis and the TOP assay. Historically, packages designed for unclean water have been used, but to simplify ordering, analysis, and reporting, we now introduce specific packages for this matrix. This also applies to the reporting limits (LOQ). Two packages for target analysis are offered: one, PFAS18, includes regulated PFAS (PFOS, PFHxS, PFOA, PFHxA etc.) as well as other common PFCA, PFSA, and FTS substances. The second package contains 45 PFAS and covers additional “simple” precursors as well as AFFF constituents such as 6:2 FTAB and DPOSA. Our TOP package comprises the same 18 compounds as the target package and includes the C4–C9 PFCA most frequently formed during TOP oxidation (also for compounds included in the PFAS 45 package). It is our recommendation that a target analysis is performed together with the TOP assay; therefore, we introduce a PFAS18 combo pack for easy ordering.

If the foam is concentrated or “ready-to-use” (e.g. 3% or 6% dilutions) 50ml (min 20ml), preferably in one of our 100ml plastic PFAS bottles is required. Delivery time (TAT) is 10 working days. If the sample matrix instead is e.g. rinse water from cleaning or firefighting water, please use one of our packs for unclean water such as PLWLY (PFAS21), PLW8K (PFAS24) or PLW9E (PFAS30) and send 2x100 ml in our PFAS bottles. Bottles can be ordered on our website free of charge. It is very important that the matrix is ​​stated on the order and that you warn of possible high PFAS levels. Further information on the new foam packs and our packages for unclean water can be found in our online catalogue and in our flyer.

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Eurofins Food & Feed
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Links

Eurofins AFFF product sheet
Eurofins online catalogue
KEMI (Chemicals Agency) PM 6/15