The study, published today in the Food Additives and Contaminants journal, found the vast majority of paper straws tested contained synthetical chemicals, known as poly- and perfluoroalkyl substances or PFAS. Commonly referred to as “forever chemicals,” PFAS don’t break down in the body or in the environment.

“Straws made from plant-based materials, such as paper and bamboo, are often advertised as being more sustainable and eco-friendly than those made from plastic,” Thimo Groffen, PhD, author of the study and an environmental scientist at the University of Antwerp, said in a press release. “However, the presence of PFAS in these straws means that’s not necessarily true.” 

Researchers on the study examined 39 brands of straws in Belgium from supermarkets, toy stores, fast-food chains, drug stores, and e-commerce stores. The straws were either made of paper, bamboo, glass, stainless steel, or plastic, and the researchers tested each brand for concentrations of PFAS. Sixty-nine percent of the brands contained PFAS, with paper straws more likely to contain the chemicals. The researchers found 90% of paper straws had PFAS, compared to 80% of bamboo straws, 75% of plastic straws, and 40% of glass straws. Further, a paper straw brand was the brand with the highest PFAS concentration.  

Perfluorooctanoic acid (PFOA) was the most common PFAS found in the straws. Though it is no longer made in the U.S. it is made in some other countries and could potentially be in products bought by American consumers, according to The American Cancer Society.

The risks of forever chemicals 

PFAS were first introduced in the 1940s to help products resist oil, water, and grease. The “forever chemicals” are found in countless products, from cookware to carpets and fabrics, according to the U.S. Centers for Disease Control and Prevention (CDC). While PFAS can enter food through plants, animals, and contaminated processing centers, “it is also possible for very small amounts of PFAS to enter foods through food packaging, processing, and cookware,” according to the U.S Food and Drug Administration. 

Small amounts of PFAS do not pose a risk. However, a build-up of the chemicals in the body may cause dangerous health effects from changes in liver enzymes, increased blood pressure, and certain cancers, according to the CDC (although long-term human effects are still not fully understood because only animal studies have been conducted with larger concentrations of PFAS). Animal studies suggest more significant amounts of PFAS in the body may affect growth and development as well as damage the liver and immune system, according to the CDC.

Due to this concern, the FDA has been testing foods for PFAS since 2019 to estimate the population’s level of exposure.  

“If the agency finds that the level of PFAS creates a health concern about a particular food, we take action, which may include working with the manufacturer to resolve the issue and taking steps to prevent the product from entering, or remaining in, the U.S. market,” the FDA’s website reads. 

The researchers noted the amount of PFAS detected in the straws was overall low and hypothesized that contaminated soil in the making of plant-based straws (bamboo and paper) could have led to the detection of PFAS, or in the manufacturing process. It was also not understood if the chemicals were seeping into the liquids themselves. Nonetheless, it begs the question of whether or not to use paper straws in the name of sustainability. 

“The presence of PFAS in paper and bamboo straws shows they are not necessarily biodegradable,” said Groffen in the release. “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.”