The growing movement against single-use plastics has led many bars and restaurants to swap plastic straws for paper ones. On the surface, this seems like an easy win – we get to sip our drinks through an eco-friendly alternative while keeping tons of plastic out of landfills and oceans. But the truth about paper straws is more complicated.

A study conducted at the University of Antwerp found that a shocking 90% of so-called eco-friendly paper straws actually contain traces of “forever chemicals.” Forever chemicals, more formally known as per-and polyfluoroalkyl substances (PFAS), are compounds that don’t break down once released into the environment or our bodies. They stick around virtually forever, which is how they got their ominous nickname.

PFAS have been linked to concerning health effects including high cholesterol, reduced immune response, thyroid disease, and increased risk of certain cancers. So why are they turning up in paper straws? The researchers tested 39 different brands of straws made from various materials like paper, bamboo, glass, stainless steel, and plastic. PFAS were detected in the majority – 69% overall.

But paper straws were by far the worst offenders, with PFAS identified in a whopping 90% of brands tested. The concentrations varied quite a bit, but the frequent presence of the chemicals suggests they were likely intentionally added in some cases. PFAS are sometimes used as a water-resistant coating – not something you want leaching into your daily iced tea.

Among the PFAS found in paper straws was perfluorooctanoic acid (PFOA), which has actually been globally banned since 2020 due to health risks including cancer and organ damage. Also frequently detected were other concerning PFAS chemicals trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFMS). While bamboo straws fared slightly better than paper ones, PFAS was still found in 80% of the bamboo brands tested. Plastic and glass straws also occasionally contained PFAS, though less commonly than plant-based options.

The one material that seems safest is stainless steel – the researchers did not detect any PFAS compounds in the steel straws analyzed. While the PFAS levels measured in this study were fairly low, these chemicals have the ominous ability to accumulate in the human body and the environment over time. The findings raise the question – if paper straws leach PFAS into our drinks over months and years of use, could they be harming our health?

Unfortunately the current research didn’t examine whether the chemicals transfer into liquids. But previous studies have shown PFAS can migrate from food packaging materials into actual food and drinks. More research is critically needed to determine if PFAS leach out of paper straws during typical use.

In the meantime, it’s clear we need to rethink the assumption that paper and other plant-based products are inherently better for health and sustainability compared to plastic. The revelation about paper straws casts doubt on the idea that swapping plastic for paper is a foolproof eco-friendly solution. After all, PFAS spreading from straws into waterways and landfills still contribute to environmental contamination – regardless of that paper label.

The study was published in the journal Food Additives and Contaminants.