Dear Kate Review, Is Dear Kate Non-Toxic?
Across 4 graded products, Dear Kate averages Poor (48/100). On disclosure, the brand says nothing publicly about PFAS. 2 of its products grade Good or better. Grades are model-based estimates, not lab results.
PFAS Authority is a scoring system, not a laboratory. We do not test products ourselves. Grades are model-based, built from published ingredients, materials, certifications, brand disclosures and third-party lab results where they exist. See the rubric.
Worth buying from Dear Kate Good or better, best-graded first
Dear Kate
Women's FSA-Eligible Dear Kate Period Underwear Ada Brief Full
Organic cotton blend, absorbent core
Formaldehyde / VOCs
If the absorbent core uses antimicrobial or moisture-wicking finishes…
Pesticide residue
Organic cotton eliminates pesticide allergens. However, no fragrance disclosure or…
Lower concern; organic cotton base unlikely to contain PFAS.
⚠Starting grade for this product type
Dear Kate
Women's Dear Kate Billie Hipster Full Panty
Organic cotton with synthetic elastic
Heavy metals
No dye sourcing or testing information is published by Dear Kate. Organic cotton…
Elastic degradation and microplastic shedding
Synthetic elastic (spandex/polyurethane) can degrade with heat and abrasion, releasing…
Undisclosed allergens in synthetic materials
The specific elastic composition (rubber, spandex blend) and processing additives are not…
Organic cotton base with no PFAS disclosure from brand.
⚠Starting grade for this product type
Graded and flagged Poor and Bad, we’d swap these
Dear Kate
Period Panties – Ada Hipster Full
Nylon/spandex blend with waterproof treatment (unspecified)
PFAS
Waterproof treatment composition is undisclosed. Most nylon period panties use either…
Degradation of waterproof coating over time
User reports on consumer sites note that waterproof integrity decreases with washing and…
Residual dyes and processing chemicals in nylon
Nylon fabric requires dyeing and finishing. If not certified organic or OEKO-TEX…
Contact dermatitis or allergic reaction
Any textile can cause irritation in sensitive individuals, particularly in prolonged…
No PFAS disclosure. Waterproof panties likely use water-repellent coating treatment; composition unclear.
⚠Waterproof or stain-proof treatment
Dear Kate
Women's Dear Kate Period Panties – Nellie Brief Full
Organic cotton with waterproof/absorbent backing, unspecified treatment
Teflon-type coating/Teflon-family coating fume risk (from waterproof backing)
If the backing uses Teflon-type coating-based coatings, normal laundering and body heat…
Coating degradation and microfiber shedding
Waterproof backings degrade over time with repeated washing and friction. Degraded…
Skin irritation from undisclosed treatment chemicals
Organic cotton reduces pesticide exposure, but the waterproof backing may contain…
Period panties with unspecified waterproof backing; contact brand for coating details.
⚠Waterproof or stain-proof treatment
Dear Kate and PFAS, common questions
- Does Dear Kate have PFAS?
- We graded 4 Dear Kate products, averaging Poor (48/100). 2 grade Good or better. Grades are model-based estimates built from published materials, ingredients and disclosures, not lab tests.
- Is Dear Kate non-toxic?
- Women's FSA-Eligible Dear Kate Period Underwear Ada Brief Full is the highest-graded Dear Kate product we have scored, at 70/100. It depends on the product line rather than the brand, so check the grade of the exact item you are buying.
- Which Dear Kate products are lower concern for PFAS?
- The highest-graded Dear Kate products we have scored are Women's FSA-Eligible Dear Kate Period Underwear Ada Brief Full, Women's Dear Kate Billie Hipster Full Panty. That is our model-based estimate from materials and public disclosure, not a lab test.
- Which Dear Kate products should I avoid?
- The lowest-graded Dear Kate products we have scored are Women's Dear Kate Period Panties – Nellie Brief Full, Dear Kate Period Panties – Ada Hipster Full. Each one links to the evidence behind its grade.
Every grade uses the same public rubric. How grades work →