Stain-resistant clothing, fast-food wrappers, and extreme weather gear such as certain jackets and pants—these products get many of their desirable features from a class of manufactured chemicals called per- and polyfluoroalkyl substances (PFAS). But there’s a major downside: Researchers have found evidence that certain PFAS can potentially cause cancer and other serious health effects.

Governmental agencies and environmental organizations are increasingly monitoring PFAS, but there are thousands of different chemical structures of PFAS with only a small fraction that can be measured with high confidence.

Scientists widely use the technique of mass spectroscopy to identify unknown molecules, including the forever chemicals known as PFAS. Credit: S. Singha/Shutterstock.

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