Women's Bottom Turn Racerback Bikini Top vs Sidestroke: which is safer?
Patagonia Women's Bottom Turn Racerback Bikini Top is the clear pick. Summersalt Sidestroke 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
Summersalt
Sidestroke
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleAzo dyes in synthetic fibers
PossibleFormaldehyde resins in fabric finishing
ReportedSpandex polymer 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 Summersalt.
- We flag Azo dyes in synthetic fibers, Formaldehyde resins in fabric finishing, Spandex polymer degradation and microfiber shedding and Allergic reaction to spandex or dye components on the Summersalt and not on the Patagonia.
- The Patagonia is Nylon/polyester blend with elastane (standard swimwear) where the Summersalt is Swimwear fabric (likely nylon/spandex blend), which is most of the difference in these two grades.
- The gap is 25 points, wide enough that this is not a close call, and the Patagonia is the one to buy.
Both products run through the same public rubric: 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 →
More swimwear: see the full ranking