PFAS in Swimwear: What “Quick-Dry” Is Often Doing
PFAS in swimwear comes down to a promise on the hangtag: quick-dry, water-repellent, stays-looking-new.
Those properties are frequently delivered by a fluorinated finish, and fluorinated finishes are PFAS, the forever chemicals that don’t break down in the environment or in people. Same family we cover in nonstick cookware, doing a similar job for a similar reason: nothing else repels water and oil as well.
A 2024 investigation by Arnika, IPEN and CHEM Trust tested 72 clothing items, swimsuits among them. PFAS turned up in 46 of them, about 64%.
The most commonly detected substance was PFOA, which has been banned globally under the Stockholm Convention for years.
Why a banned chemical keeps turning up
Two reasons, and neither is comforting.
PFOA persists. It’s in the environment, in recycled feedstocks, and in the supply chains that make textile finishes, so it appears as a contaminant in products nobody deliberately added it to.
And enforcement of textile chemistry across global supply chains is thin. A brand can specify a PFAS-free finish and receive fabric treated with something else entirely, and unless it tests, it won’t know. Most don’t test.
That’s the uncomfortable part of this category: the brand telling you its swimsuit is PFAS-free may sincerely believe that and be wrong, because belief and testing are different things. It’s the same gap we keep running into with certification claims taken off a supplier’s word.
Does a swimsuit even need it
Mostly not, and that’s what makes this an easy thing to avoid.
Swimwear fabric is nylon or polyester with elastane. Those fibers are already hydrophobic. They don’t absorb much water, they dry reasonably fast on their own, and a swimsuit’s job description does not include repelling water while you are submerged in it.
The finish is doing marginal work: drying slightly faster, resisting oils and sunscreen stains. Useful, minor, and not worth a persistent chemical against skin in the sun for hours.
Technical outerwear is a harder trade, because a rain jacket that wets out has failed at its only job. A swimsuit is not that.
How to avoid it
Skip the finish claims. “Quick-dry,” “water-repellent,” “stain-resistant” and DWR on a swimsuit are the language to be suspicious of, and none of them describes something you need in the water.
Look for an explicit PFAS-free statement, ideally with testing behind it rather than a supplier assurance. A brand that says “we test for PFAS” is telling you more than one that says “we don’t use PFAS.”
OEKO-TEX Standard 100 helps, since its restricted substance list covers PFAS and it’s a test of the finished fabric rather than a promise about inputs. That’s the same reason it’s useful in bedding.
And know that this is separate from the fiber question. A suit made from recycled nylon can still carry a PFAS finish, because the finish is applied to the fabric regardless of where the fiber came from. Recycled content and PFAS-free are two different claims and brands are happy to let one imply the other.
The picks in the best sustainable swimwear brands are screened on both, and every brand there has a scored profile in our brand directory.
Frequently asked questions
Do swimsuits contain PFAS?
Many do. Testing of 72 clothing items by Arnika, IPEN and CHEM Trust found PFAS in 46 of them, roughly 64%, with swimsuits included in the sample. The most commonly detected substance was PFOA, which is banned globally under the Stockholm Convention yet persists as an environmental and supply-chain contaminant.
Why would swimwear need a water-repellent finish?
It largely doesn’t. Nylon and polyester are already hydrophobic and dry quickly on their own. A fluorinated finish speeds drying marginally and adds oil and stain resistance, which is a small benefit relative to wearing a persistent chemical against skin for hours.
Does recycled swimwear mean PFAS-free?
No. The two are unrelated claims. Finishes are applied to the fabric regardless of whether the fiber is virgin or recycled, so a suit made from recycled nylon can still carry a PFAS treatment. Look for both claims separately.
How can I tell if a swimsuit has PFAS?
You often can’t from the label, since finishes rarely appear in the fiber content. Treat “quick-dry,” “water-repellent” and “stain-resistant” as warning language, look for an explicit PFAS-free statement backed by testing, and favor OEKO-TEX Standard 100, whose restricted list covers PFAS in the finished fabric.
Related reading
The rest of this series: what Econyl and recycled nylon actually do and microplastic shedding from swimwear. For vetted picks, see the best sustainable swimwear brands. The same chemical family in the kitchen is covered in PFAS in nonstick cookware.
Sources: Arnika, IPEN and CHEM Trust, PFAS in children’s clothing testing, 2024. Stockholm Convention, Listing of PFOA. OEKO-TEX, Standard 100 restricted substances.
