Women's DD-Cup Tummy Control Square Neck Underwire Tankini Swimsuit Top vs Women's Bottom Turn Racerback Bikini Top: which is safer?

Where these two actually differ

• We flag PFAS in water-repellent finish, Azo dyes, Spandex degradation and skin contact and Formaldehyde-based finishes on the Lands' End and not on the Patagonia.
• We flag Elastane (spandex) degradation under heat or chlorine on the Patagonia and not on the Lands' End.
• The Lands' End is nylon/spandex blend with tummy-control panel; likely water-resistant 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 Lands' End grade, at 42% confidence against 72%, because it discloses less.