Is Proof PFAS-free?
Across 8 graded products, Proof averages F (34/100). On disclosure, the brand says nothing publicly about PFAS. 1 of its products grade C or better. Grades are model-based estimates, not lab results.
Worth buying from Proof C or better, safest first
Proof
The High Waisted Period. in Organic Cotton For Heavy Flows
Organic cotton (primary); absorbent core material unspecified
Lower PFAS concern for core material, but lack of transparency on absorbent layers leaves some uncertainty.
⚠Risky category by default
Graded and flagged D and F, we’d swap these
Proof
Period Period Underwear
Organic cotton gusset + proprietary waterproof layer
Lower-concern option if PFAS-free claim holds, but unverified by third party.
⚠Waterproof or stain-proof treatment
Proof
Women's Overnight Absorbency High Rise Period Underwear
Gusseted absorbent fabric with waterproof/stain-resistant layer (unspecified treatment)
Period underwear typically uses water/stain-resistant coatings; Proof discloses nothing about PFAS or treatment chemistry, skip unless they publish ingredient de
⚠Waterproof or stain-proof treatment
Proof
Women's Super Heavy Absorbency Period Underwear
Cotton/synthetic blend with waterproof coating layer
Skip until brand discloses waterproof treatment chemistry; PFAS risk present but unconfirmed.
⚠Waterproof or stain-proof treatment
Proof
Knix Intimates & Sleepwear Knix Super Leakproof Dream Short
Fabric with unspecified waterproof/leakproof coating
Skip until brand discloses coating chemistry, period underwear's waterproof layer is a PFAS red flag.
⚠Waterproof or stain-proof treatment
Proof
. by Always High Rise Washable Period Underwear
Cotton blend with waterproof/moisture-barrier coating (type unspecified)
Skip until the brand discloses waterproof coating chemistry, washable period underwear typically uses water-repellent coating treatments that often contain PFAS.
⚠Waterproof or stain-proof treatment
Proof
Boody Bamboo Underwear Period & Leak Proof Full Brief
Bamboo viscose blend with waterproof leak-proof coating (unspecified)
Leak-proof underwear requires waterproof coating, brand won't disclose what it is.
⚠Waterproof or stain-proof treatment
Proof
Women's Mid-Waist Leak-Proof Period Underwear
Cotton/polyester blend with waterproof gusset lining (likely water-repellent coating-treated)
Skip until Proof discloses waterproofing chemistry, period underwear's leak-proof gusset raises PFAS questions they don't answer.
⚠Waterproof or stain-proof treatment
Every grade uses the same public rubric. How grades work →