Pollution of soils by PFAS/PFC

Per- and polyfluoroalkyl substances (PFAS) are organic fluorine compounds with more than 4,700 different substances. They are manmade chemicals that have been produced since the 1940s and consist of carbon chains of different length with multiple fluorine atoms attached. Most common are the perfluorosulfonic acids (e.g. PFOS) and the perfluorocarboxylic acids (e.g. PFOA) as well as their precursor. Precursor are substances that can degrade to PFAS.

PFAS are water, grease and dirt repellent as well as chemical- and heat-resistant. Due to these unique properties, they are processed in numerous consumer products such as cosmetics, non-stick coated pans, paper, textiles or ski waxes. In addition, PFAS are used for the surface treatment of metals and plastics, in pesticides and fire-fighting foams and in a variety of other areas.

Because of their chemical and thermal stability PFAS are also called 'forever chemicals' because they accumulate in the environment and are found worldwide in soil, ground- and surface water as well as in the blood and tissue of animals and humans.

Scientific findings in the last years have made it clear that PFAS pose a serious risk to humans and the environment. This in combination with their persistency make them especially critical.

At the behest of the German Conference of Environment Ministers PFAS-Guidelines were elaborated by the Federal Ministry for the Environment and experts from the German federal states. The guidelines give an overview of the current situation and give recommendations for the uniform nationwide assessment of soil and water contamination and for the disposal of soil material containing PFASs.

In the context of the German EU Council Presidency, the international virtual conference was jointly organized and hosted by the German Federal Ministry for the Environment (BMU) and the German Federal Environment Agency (UBA) as a virtual event from 30 November to 1 December 2020. It offered a platform for the various experts involved with chemical risk assessments and PFAS contaminations to present and discuss current challenges and regulations as well as national and international management examples and strategies. It facilitated the exchange of information and the share of best practices internationally.

Over 700 participants from 30 countries took part and the great interest showed again that PFAS in the environment are a highly topical and sensitive subject.

The treatment and remediation of PFAS contaminations can be very difficult and expensive, as the well-established remediation techniques are often not effective due to the different substance properties of the PFAS.

The work aid supports the responsible authorities in the pre-selection, evaluation and decision for a suitable and proportionate remediation procedure, shows relevant basic conditions and accompanying measures. The advantages and disadvantages, the technical and approval requirements as well as their sustainability are shown for the possible remediation methods.