What I Found When I Went Looking for Plastic-Free Swimwear

Most swimwear sits against skin for hours in warm, wet conditions that open pores. Synthetic fabrics can shed microplastics and leach chemicals like PFAS and formaldehyde during contact, which is part of why polyester and nylon are common eczema and rash triggers. Dyes matter too: even a natural fiber suit can carry a toxic load if it isn't dyed cleanly, which is why the certifications below are worth knowing about.

Four years ago I landed on a Patagonia suit made from recycled nylon and recycled polyester, which seemed like a reasonable choice. Turns out it wasn't. Suits made from recycled fabrics shed more microplastics than conventional polyester, not less, because recycled fibers are more degraded and release particles more readily. Swimwear is especially problematic because it consists almost entirely of cut edges, which is where most fiber shedding happens. Putting a recycled suit in the ocean deposits microplastics directly into the water and skin you're trying to protect.

The options are better now than when I started looking, although I still haven't quite found the perfect suit for me. I'm a small but size down to XS in natural fibers since they tend to stretch out in water, and I prefer boyshorts. Those two things together narrow my field considerably, but the options that didn't work for me might work well for you.

A note on certification

When shopping for natural fiber swimwear, two certifications are worth knowing. GOTS (Global Organic Textile Standard) covers the entire supply chain, including dyeing, and prohibits toxic chemicals and heavy metals. OEKO-TEX Standard 100 tests finished textiles for harmful substances including PFAS, formaldehyde, and phthalates. If a brand doesn't have either certification, ask directly about their dye process.

For wool specifically: "machine washable" almost always means superwash treated, which involves a chlorine process and often a plastic coating that undoes most of what makes wool worth wearing. Look for brands that state explicitly that their wool is untreated or non-superwash.

What I found for women

Una Pluma makes two bodysuits from 95% organic cotton and 5% Lycra, dyed with low-impact dyes, fairly traded from Nepal. They are offered as alternative swimwear. They go from S to XL, no XS or XXL. Their separate bra and bottom styles work in water too, same fabric. I got the black boyshort and striped brallette, both in S. If the boyshort were double-lined and came in XS, this would work better for my body. However, it's at least an affordable option for sauna and more private swimming where I don't mind that the shorts are a little baggier than I'd like.

Branwyn makes clean wool underwear, and I've read quite a few reviews that both tops and bottoms hold up well in water, though fit varies by person. The blend is 81% ZQ+ merino, 14% nylon, and 5% elastane, so not pure wool, but it's Woolmark and OEKO-TEX Standard 100 certified and explicitly PFAS and BPA free. I'm planning to try the boyshort since it runs in XS.

Zubek's sets and one piece are 98% merino wool and 2% elastane, sourced from New Zealand and spun, woven, cut, and sewn in Poland. They're OEKO-TEX Standard 100 certified, and they explicitly state no superwash and no Hercosett plastic resin, which is the treatment I mentioned above to watch for. Limited colors and coverage, but their fabric is honest.

Swimm Merino and Simply Merino make merino wool two-piece and one-piece suits that come in a range of beautiful colors but expensive and frequently out of stock.

BeachCandy Organics is handmade in Los Angeles from hemp and organic cotton. Undyed styles use zero synthetics from thread to finish. Colored styles use AZO-free, plant-safe dyes. The bandeau top is 53% hemp and 47% organic cotton, and they make a bodysuit version too. The styles aren't for me, but the materials are clean.

Pure Earth Collection's Earthcove line is made from 98% GOTS-certified organic cotton with 2% Lycra, with a wide range of bikini sets and one-pieces.

Piuma makes 100% organic cotton swimwear with OEKO-TEX certified dyes, in S/M through L/XL. A good affordable option if you're in that size range and want something with color and shape, although neither top nor bottom is double-lined. No XS or XXL.

Indie Attire is handmade in Paia, Hawaii by Sara, who has been making swimwear since 2010. The hemp and organic cotton collection is 53% hemp, 43% organic cotton, and 4% Lycra, double-lined with the same fabric. Sizes XS through XL. Limited color and style

options, but the construction seems genuinely good and it's US made.

What I found for men

One of the best options I've come across for men is Alex Crane's Bananatex shorts, made from banana plant fiber in collaboration with Bananatex, a plastic-free natural material. For questions about dye and chemical treatment, I'd contact them directly. They go up to XXL.

Zubek makes swim trunks for men as well. Three total: two different versions of 98% merino wool, 2% elastane shell, with a 100% merino support pouch instead

of the usual polyester mesh liner, and one pair of 68% TENCEL Lyocell, 29% seaweed fiber, 3% elastane, same 100% merino liner all OEKO-TEX certified.

Sheep Inc. makes merino wool swim shorts with a stated goal of microplastic-free performance. Expensive, and they don't disclose the full details of fiber treatment, so it's worth asking about superwash before ordering.

Industry of All Nations and Pure Earth Collection round out the options, though both tend to stop at XL.