First Evidence for the Environmental Occurrence of Water-Soluble Polyquaternium Polymers

Water-soluble polymers (WSPs) are produced and used in large volumes but are exempted from REACH, resulting in a blind spot in chemical regulation. In light of the current revision of REACH, cationic polymers like polyquaternium (PQ) polymers have been flagged as potential “polymers of concern” due to the first evidence of their toxicity and persistence, yet little is known about their environmental occurrence. In this study, a novel approach for WSP trace analysis was adopted for PQs and used to screen for PQ2, -6, -7, and -10 in 15 surface waters taken in the region of Leipzig, Germany. This first environmental data showed a widespread occurrence of PQ2, which was detected in 13 of 15 samples, while PQ7 and -10 were detected in three and four samples, respectively. While accurate quantification is currently not feasible due to a lack of high-quality standards, PQ2 concentrations were estimated to be in the range of 10–1000 μg/L. Based on these estimates, concentrations in eight samples potentially exceed LC50 (rainbow trout and Daphnia magna) and ErC50 (Scenedesmus suspicatus) values reported for PQ2. Due to the complex interactions of PQs with natural organic matter, the extent to which detected PQs are bioavailable and thus may show adverse environmental effects remains unclear.