From an article published in the Ecotoxicology and Public Health (please see citation below).

Key Points

• Fluorinated compounds like PFAS are a large class of chemicals linked to a wide variety of health impacts.
• Limited information is known on the PFAS content in reusable feminine hygiene products, both in the United States and abroad.
• In this study, 59 reusable feminine hygiene products across five product categories first underwent total fluorine screening to detect possible PFAS use in products.
• Period underwear and reusable pads appeared to have the greatest rates of intentional PFAS use at 33% and 25%, of products tested respectively.

Reusable feminine hygiene products like period underwear and pads can be good options for some people. In theory, they can reduce plastic and paper waste associated with single use products, and may offer lower overall environmental impacts across their lifecycle when they are used over a long enough period of time. But because some companies are trying to achieve specific waterproofing or stain resistant properties, they (or their suppliers) turn to coating fabrics used in these kinds of products with PFAS chemicals. Like many ingredient safety and sustainability issues, these kinds of trade-offs across different kinds of impacts are common.

In our homes, we try and limit our exposures to these kinds of chemicals by choosing products that have trustworthy ingredient safety certifications like EWG VERIFIED and Made Safe. Ingredient safety is a big part of our company ratings, so looking for products made by companies that are rated as "Recommended" is also a good option.

Alyssa Wicks, Sydney Brady, Heather D. Whitehead, Thomas Hedman, Alison Zachritz, Marta Venier, and Graham F. Peaslee. Environmental Science & Technology Letters 2025 12 (8), 924-929 DOI: 10.1021/acs.estlett.5c00553