Women's Bottom Turn Racerback Bikini Top vs Women's Ultraback One Piece Swimsuit: which is safer?
Patagonia Women's Bottom Turn Racerback Bikini Top is the clear pick. Speedo Women's Ultraback One Piece Swimsuit carries a failing PFAS grade, and we never recommend buying a failing product.
Our pick
Patagonia
Women's Bottom Turn Racerback Bikini Top
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleElastane (spandex) degradation under heat or chlorine
Speedo
Women's Ultraback One Piece Swimsuit
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
Possiblewater-repellent coating finish chemistry (undisclosed)
PossibleFiber degradation and microfiber shedding
Where these two actually differ
- We flag Elastane (spandex) degradation under heat or chlorine on the Patagonia and not on the Speedo.
- We flag DWR finish chemistry (undisclosed) and Fiber degradation and microfiber shedding on the Speedo and not on the Patagonia.
- The Patagonia is Nylon/polyester blend with elastane (standard swimwear) where the Speedo is Nylon/polyester blend with durable water repellent (DWR) finish, which is most of the difference in these two grades.
- The gap is 70 points, wide enough that this is not a close call, and the Patagonia is the one to buy.
- We are less certain about the Speedo grade, at 45% confidence against 72%, because it discloses less.
Both products run through the same public rubric, which covers materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →
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