Plant-based drinking straws found to contain PFAS

In the first known analysis of its kind in Europe, and only the second in the world, Belgian researchers have tested 39 brands of straws for the group of synthetic chemicals known as poly- and perfluoroalkyl substances (PFAS). PFAS were found in the majority of the straws tested and were most common in those made from paper and bamboo.

PFAS are used to make everyday products, from outdoor clothing to non-stick pans, resistant to water, heat and stains. The downside is that they break down very slowly over time and can persist over thousands of years in the environment, a property that has led to them being known as ‘forever chemicals’. They have also been associated with health problems including lower response to vaccines, lower birth weight, thyroid disease, increased cholesterol levels, liver damage, kidney cancer and testicular cancer.

A growing number of countries have banned sale of single-use plastic products, including drinking straws, and plant-based versions have become popular alternatives. But with a recent study finding PFAS in plant-based drinking straws in the US, researchers at the University of Antwerp wanted to find out if the same was true of those on sale in Belgium.

The research team purchased 39 different brands of drinking straw made from five materials — paper, bamboo, glass, stainless steel and plastic. The straws, which were mainly obtained from shops, supermarkets and fast-food restaurants, then underwent two rounds of testing for PFAS. The results were published in the journal Food Additives & Contaminants: Part A.

The majority of the brands (27 out of 39, or 69%) contained PFAS, with 18 different PFAS detected in total. The paper straws were most likely to contain PFAS, with the chemicals detected in 18 of 20 (90%) of the brands tested. PFAS were also detected in four in five (80%) brands of bamboo straw, three in four (75%) of the plastic straw brands and two in five (40%) brands of glass straw. They were not detected in any of the five types of steel straw tested.

The most commonly found PFAS, perfluorooctanoic acid (PFOA), has been banned globally since 2020. Also detected were trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFMS), ‘ultra-short chain’ PFAS which are highly water soluble and so might leach out of straws into drinks; the study did not investigate this, however.

The researchers acknowledged that PFAS concentrations were low and, bearing in mind that most people tend to only use straws occasionally, pose a limited risk to health. However, PFAS can remain in the body for many years and concentrations can build up over time.

It isn’t known whether the PFAS were added to the straws by the manufacturers for waterproofing or whether they were the result of contamination. According to the researchers, the presence of the chemicals in almost every brand of paper straw means it is likely that it was, in some cases, being used as a water-repellent coating.

“The presence of PFAS in paper and bamboo straws shows they are not necessarily biodegradable,” stated Antwerp researcher Dr Thimo Groffen.

“We did not detect any PFAS in stainless steel straws, so I would advise consumers to use this type of straw — or just avoid using straws at all.”

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