The Last Straw: Characterization of Per- and Polyfluoroalkyl Substances in Commercially Available Plant-Based Drinking Straws

Mean Sum PFAS Measured

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Alina Timshina1#, Juan J. Aristizabal-Henao1#, Bianca F. Da Silva1, John A. Bowden Center for Environmental and Human Toxicology, Department of Physiological Sciences, University of Florida

Paper and other plant-based drinking straws are replacing plastic straws in commercial settings in response to trending plastic straw bans and the larger global movement for reducing plastic pollution.

The water-resistant properties of many plant-based straws, however, may be attributed to the use of per- and polyfluoroalkyl substances (PFAS) during manufacturing. In this study, 43 brands of straws (5 plastic, 29 paper, 9 other plant-based) were analyzed for the presence of 53 semi-volatile PFAS using ultra high-performance liquid chromatography tandem mass spectrometry.

While the plastic straws had no measurable PFAS, 21 PFAS were detected in the paper and other plant-based straws, with total mean PFAS concentrations (triplicate analysis) ranging from 0.043 ± 0.004 ng/straw to 29.1 ± 1.66 ng/straw (median = 0.554 ng/straw). Perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA) were the most frequently detected species.

In a follow-up experiment, the brand with the highest PFAS levels and most diversity was tested for leaching in water at initial temperatures of 4 °C, 20 °C, and 90 °C. Approximately 2/3 of the total extractable PFAS leached compared to the initial methanol extraction. Semi-volatile PFAS concentrations measured in this study may be the result of manufacturing impurities or contamination, as PFAS approved for food-contact use are, typically, polymeric species.

The presence of PFAS in plant-based drinking straws demonstrates that they are not fully biodegradable, contributing to the direct human ingestion of PFAS and to the cycle of PFAS between waste streams and the environment.

Source: https://www.sciencedirect.com/science/article/abs/pii/S0045653521007074?via%3Dihub