Recycled flooring contains phased-out chemicals

An analysis of 151 polyvinyl chloride (PVC) flooring products on the market in Switzerland found that 16% of them contained measurable levels of chemicals that have been phased out (Environ. Sci. Technol. 2024, DOI: 10.1021/acs.est.3c04851) . Researchers were particularly alarmed to find products containing lead, a toxic metal that was previously added to PVC products to stabilize them, and the plasticizer bis(2-ethylhexyl) phthalate (DEHP). DEHP is an ortho-phthalate, a group of chemicals associated with a large number of health problems, including endometriosis, cancer, asthma, and type 2 diabetes.

It’s likely that the legacy chemicals were not added on purpose, says lead author Helene Wiesinger, a doctoral student at the Institute of Environmental Engineering of the Swiss Federal Institute of Technology (ETH), Zurich. That’s because in most of the samples, their concentrations were tenths of a percent to a few percent by weight—too low to be useful. For example, PVC products typically contain 5–60% plasticizers, depending on the application, Wiesinger says.

Wiesinger’s team conducted this research as part of a larger project to recommend ways to increase rates of recycling in Switzerland. She says flooring and other materials from torn-down buildings should be diverted from landfills, but recycling efforts must exclude products that contain legacy chemicals. It’s not just flooring. Other researchers have found that toys, utensils, and other consumer products that incorporate recycled plastics contain phased-out brominated flame retardants and other legacy chemicals.

“If you want to make sure you have clean materials, you need screening tools,” Wiesinger says. She’s talking to recyclers about whether they could adopt X-ray fluorescence, one of the tools used in the study, to decide which flooring materials to send to a landfill.