Flex Review, Is Flex Non-Toxic?
Flex averages 70 out of 100 on PFAS Authority's PFAS and toxin screen across the 7 Flex products graded as of October 2026, and all 7 reach its 70 point pass mark.
Flex grades Good on our four-band scale. On disclosure, the brand says nothing publicly about PFAS. See what every brand has published about PFAS for how that compares.
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.
You may also be interested in
Top-graded picks in the categories readers replace first, every one scored on the same rubric.
- polypropylene filter housing, carbon/sediment cartridge
- We found no PFAS statement from the brand
- Bacterial growth in spent cartridges
3 hazards checked on this product, all on its full breakdown.
Aquasure
Premier Series 75 GPD Under Sink Reverse Osmosis Water Filtration System
- RO membrane, carbon filters, stainless steel housing
- We found no PFAS statement from the brand
- Bacterial and microbial growth in housing and filters
4 hazards checked on this product, all on its full breakdown.
Avocado
Vegan Mattress
- organic cotton, natural latex, coconut coir, recycled steel coils
- The brand calls it PFAS-free, which we have not verified
- Heavy metals
2 hazards checked on this product, all on its full breakdown.
Does Flex have PFAS, by category
Which Flex products are PFAS-free? Good or better, best-graded first
- Medical-grade silicone
- We found no PFAS statement from the brand
- Bacterial or mold colonization from poor maintenance. Any menstrual cup can harbor bacteria or fungal growth…
2 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone, no added Teflon-family coating
- We found no PFAS statement from the brand
- Residual manufacturing compounds / silicone impurities. Medical-grade silicone undergoes purification, but…
2 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone
- We found no PFAS statement from the brand
- Bacterial or fungal colonization. Any reusable menstrual cup can harbor bacteria or fungi if inadequately…
2 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone
- We found no PFAS statement from the brand
- Silicone degradation and particle shedding. Medical-grade silicone can degrade if exposed to very high heat…
2 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone
- We found no PFAS statement from the brand
- Silicone degradation and particulate shedding. Medical-grade silicone is stable under normal use, but…
4 hazards checked on this product, all on its full breakdown.
- medical-grade silicone
- We found no PFAS statement from the brand
- Bacterial or fungal contamination. While silicone itself resists microbial biofilm better than latex…
3 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone (body-contact surface)
- We found no PFAS statement from the brand
- Bacterial or fungal biofilm growth on cup surface. If cups are stored wet or in airtight containers, or not…
3 hazards checked on this product, all on its full breakdown.
What to buy instead Good or better, in the categories Flex sells
- medical-grade silicone
- A third party reports verifying it as PFAS-free
- Silicone degradation or leaching from improper cleaning agents
3 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone (body); no Teflon-family coating coatings reported
- We found no PFAS statement from the brand
- Silicone degradation and surface microtearing
3 hazards checked on this product, all on its full breakdown.
- Medical-grade silicone (body); no reported coatings or treatments
- We found no PFAS statement from the brand
- Biofilm and bacterial growth (maintenance-dependent)
4 hazards checked on this product, all on its full breakdown.
Flex and PFAS, common questions
- Does Flex have PFAS?
- Flex averages 70 out of 100 on PFAS Authority's PFAS and toxin screen across the 7 Flex products graded as of October 2026, and all 7 reach its 70 point pass mark. Grades are model-based estimates built from published materials, ingredients and disclosures, not lab tests.
- Is Flex non-toxic?
- Flex Cup Menstrual Slim Pack of 1 is the highest-graded Flex 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 Flex products are lower concern for PFAS?
- The highest-graded Flex products we have scored are Flex Cup Menstrual Slim Pack of 1, Flex Cup Starter Bundle, Reusable Menstrual Cup. That is our model-based estimate from materials and public disclosure, not a lab test.
Every grade uses the same public rubric. How grades work →