They are a red rag for environmental associations, environment ministers and toxicologists: the per- and polyfluorinated alkyl compounds known as PFAS for short can accumulate in the environment and in the human body and are suspected of damaging the hormonal and immune systems from a certain concentration. In fact, these persistent industrial chemicals, which are contained in numerous everyday products, have been detected in 1500 places in this country, including in wastewater. When asked how some of the PFAS can get into the sewage system, an American research group from the University of Florida in Gainesville has found a surprising answer: toilet paper also contributes to the PFAS input.
Manfred Lindinger
Editor in the department "Nature and Science".
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PFAS are added to many cosmetics and detergents because of their fat-dissolving and water-repellent properties. Some paper manufacturers also add PFAS when they process wood into pulp. As a result, the chemicals can still be contained in the finished paper product, including toilet paper. Also affected is recycled toilet paper, which is often made from PFAS-containing fibers. It passes through the sewage system to the sewage treatment plants, where the paper decomposes and the PFAS chemicals can be released. Apparently, many environmental researchers have not yet had this distribution path in mind.
For their study, the researchers led by Timothy Townsend procured toilet paper rolls that were offered in North, South and Central America as well as in Africa and Western Europe. They also collected sewage sludge samples from eight US wastewater treatment plants. They then extracted and analyzed the PFAS substances contained in the samples using standardized procedures. The researchers led by Townsend were able to identify a total of six different PFAS substances, the most common of which were so-called disubstituted polyfluoroalkylphosphates (6:2 diPAP). These compounds can convert into more stable PFAS such as perfluorooctanoic acid, which is considered carcinogenic. The measured concentrations were comparatively low, they were in the ppb range (parts per billion).
Six countries in comparison
The scientists combined their measurement results with data from other studies that measured the PFAS content in selected wastewater from different countries – USA, Canada, China, Australia, France, Sweden – and recorded the per capita consumption of toilet paper there. In their study, which appeared in the "Environmental Science & Technology Letters Journal", Townsend and his colleagues have now estimated the extent to which toilet paper pollutes wastewater with Di-PAP in these countries: The contribution of toilet paper is lowest in the United States and Canada at around four percent each, where there are the highest PFAS contamination (82 ppb). The share of toilet paper is higher in Sweden (32 percent). In France, it is highest at 89 percent. In the European countries, however, the total load in the examined sludge samples is much lower at 1.7 ppb than overseas.
Despite the fact that North Americans consume more toilet paper (about 26 kilograms per person per year) than people in other countries (in Germany, for example, it is only 15 kilograms per person per year), the percentages suggest that, at least in North America, most PFAS enters sewage systems via cosmetics, textiles and food packaging, rather than toilet paper. In European countries such as France and Sweden, things seem to be different.
In other parts of the world that were not included in the study, the environmental impact could be significantly higher, the researchers write. Their study results are not an all-clear signal, but should encourage environmental authorities to focus more on PFAS inputs into wastewater. The authors do not provide any information about possible health risks. However, the researchers point out that "wastewater and sewage sludge are usually reused for irrigation or fertilization". It is already known that PFAS are released into the environment in this way.
The group of PFAS includes several thousand chemicals. They are used in numerous products such as shampoos or pizza boxes, but are also used in chip production, solar cell, battery and fuel production. Germany, Denmark, Norway, the Netherlands and Sweden are calling for a ban on "perpetual chemicals" and submitted an application to the EU Chemicals Agency ECHA in Helsinki at the beginning of February. The request is now being examined there. An implementation of the ban by the EU Commission can probably be expected in 2026 at the earliest.