Setting safe limits for two short-chained perfluoroalkyl substances for experimentally exposed soil organisms: perfluorobutane sulfonate (PFBS) and its by-product perfluorobutane sulfonamide (FBSA).

The scientific and public attention to the group of per- and polyfluoroalkyl substances (PFAS) has risen exponentially since the beginning of the 2000s. These chemicals have been produced since the 1940 in large quantities for numerous applications such as firefighting foams and fast-food packaging. Due to their production and use in several consumer products, PFAS have been distributed globally in the environment, in which they accumulate in organisms. Regulatory measures for legacy long-chained PFAS, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have led to a restriction in their production and use, with some exemptions. Nonetheless, these long-chained PFAS have often been replaced by short-chained homologues, such as perfluorobutane sulfonate (PFBS). This is also the case for 3M Zwijndrecht, Belgium, a known PFAS hotspot. As a byproduct in the production of PFBS, perfluorobutane sulfonamide (FBSA) is produced. Both chemicals are not regulated, due to the lack of data on their toxicity. As a consequence, both chemicals can be produced and used unrestrictedly, and both of them are discharged in the environment. Based on their persistency (they do not or merely break down in the environment), because they first adsorb to solid matrices after being discharged, and because it is assumed that they are equally toxic as their long-chained homologues, it is necessary to investigate the toxicity of these chemicals to soil organisms. This allows us to set safe limits to protect soil ecosystems. The objective of this study is to set such safe limits for soil ecosystems based on species sensitivity distributions.

Keywords:EXPERIMENTAL STUDY, RISK ANALYSIS, PERFLUOROALKYL SUBSTANCES (PFAS), SOIL POLLUTION

Disciplines:Environmental impact and risk assessment, Soil sciences, challenges and pollution not elsewhere classified