Saalt
Reusable period underwear can't really be plastic-free - the absorbent core and leakproof barrier are inherently synthetic (polyester and polyurethane) - and Saalt is honest about that. Where it stands out is the chemistry that actually matters in this category: after finding PFAS in a pre-launch fabric in 2020, it reformulated and now publishes recurring third-party "Not Detected" PFAS results. For period underwear, that PFAS-free transparency is the meaningful standard, not fiber purity.
How clear are their specs?
Publishes layer-by-layer fabric composition and a dated history of third-party PFAS test results - unusually transparent for the category.