Women's Tanlines Bound Sloane Hawaii One-Piece Swimsuit vs Women's Bottom Turn Racerback Bikini Top: which is safer?

Patagonia Women's Bottom Turn Racerback Bikini Top is the clear pick. Billabong Women's Tanlines Bound Sloane Hawaii One-Piece Swimsuit carries a failing PFAS grade, and we never recommend buying a failing product.

Billabong Women's Tanlines Bound Sloane Hawaii One-Piece Swimsuit

Billabong

Women's Tanlines Bound Sloane Hawaii One-Piece Swimsuit

PFAS grade

Bad 20/100

Overall grade

Bad 12/100

Verdict

Skip

Hazard flags

⚑ 2

Material

Polyester/nylon blend with water-repellent coating treatment

Confidence

45%

PossiblePFAS in water-repellent coating finish

Possiblewater-repellent coating finish degradation and microplastic shedding

Our pick

Patagonia Women's Bottom Turn Racerback Bikini Top

Patagonia

Women's Bottom Turn Racerback Bikini Top

PFAS grade

Excellent 90/100

Overall grade

Excellent 86/100

Verdict

Buy

Hazard flags

⚑ 1

Material

Nylon/polyester blend with elastane (standard swimwear)

Confidence

72%

PossibleElastane (spandex) degradation under heat or chlorine

Where these two actually differ

  • We flag PFAS in DWR finish and DWR finish degradation and microplastic shedding on the Billabong and not on the Patagonia.
  • We flag Elastane (spandex) degradation under heat or chlorine on the Patagonia and not on the Billabong.
  • The Billabong is Polyester/nylon blend with DWR treatment where the Patagonia is Nylon/polyester blend with elastane (standard swimwear), 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 Billabong grade, at 45% confidence against 72%, because it discloses less.

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