Not a fan of those paper straws that have replaced disposable plastic ones in the name of being eco-friendly? As it turns out, some of those efforts to save the environment may have been in vain.

A new study, published Thursday in the journal Food Additives and Contaminants, found evidence of “forever chemical” PFAS (per- and polyfluoroalkyl substances) in the majority of both paper and bamboo straws tested.

Scientists in Belgium tested 39 brands of straws made of paper, bamboo, plastic and stainless steel found in shops, supermarkets and restaurants across the country.

Of the straws tested, almost all contained some concertation of PFAS, which are often used during manufacturing to make products water resistant. Out of the total 39 tested, the chemicals were detected in 27, none of which were stainless steel.

Paper straws, on the other hand, were the most likely to contain PFAS, with 18 out of 20, or 90%, of paper brands testing positive. They were also found in four out of five bamboo straws, three out of four plastic straws and two out of five glass straws.

Not so eco-friendly?

Eighteen different PFAS were detected in total, though overall in low concentrations. The chemical most commonly found, however, was perfluorooctanoic acid (PFOA) which was banned globally in 2020.

“These ‘eco-friendly’ plant-based straws are not necessarily a more sustainable alternative to plastic straws,” said the study’s conclusion, “because they can be considered as an additional source of PFAS exposure in humans and the environment (e.g. after degradation in landfills or through incomplete incineration).”

The study also discovered PFAS that are known to be highly water soluble, meaning they have the potential to bleed from the straw into a drink, but did not investigate this component further.