Swimwear is a summer staple. Whether you're lounging by the pool or diving into saltwater waves, a good swimsuit is essential. But have you ever stopped to think about what it’s made from, and where it ends up?

While the fashion industry is slowly waking up to sustainability, swimwear remains one of the most problematic categories. The very materials that make swimwear functional, stretchy, quick-drying, and durable, are also those that cause some of the most harm to our oceans.

The Problem with Polyester (and Synthetics in General)

Most swimwear is made from synthetic fibers like polyester, nylon, and elastane. These materials don’t biodegrade, and worse, they shed microplastics every time they’re washed or worn in water.

Microplastics are tiny plastic particles that break off from synthetic fabrics and end up in waterways, eventually accumulating in oceans. They’re so small they're impossible to fully filter out and are now found in everything from seafood to bottled water, and even human blood.

Why does it matter?

One wash can release up to 700,000 microfibers into the water system.
Synthetic swimwear = plastic: Petroleum-based fabrics contribute to fossil fuel consumption.
These plastics are ingested by marine life and enter the food chain, with unknown long-term impacts on human health.

Can Swimwear Ever Be Sustainable?

The short answer is: it’s complicated. Because there’s no natural fiber that performs like synthetics in water, even the most “sustainable” swimwear still relies on plastic-based fabrics. But the good news is that some brands are working to reduce the damage, using recycled materials, improving production practices, and encouraging longevity through better care.

Better Fabrics:

ECONYL®: A regenerated nylon made from ocean waste like fishing nets and fabric scraps.
Recycled polyester (rPET): Repurposes plastic bottles and existing waste into new fibers.

While these options still shed microplastics, they at least help reduce waste and fossil fuel use.

How to Take Better Care of Your Swimwear

The most sustainable swimsuit is the one you already own. But how you care for it can make a big difference — both in longevity and environmental impact.

1. Rinse immediately after use
Salt, chlorine, and sunscreen break down fabric fibers. Rinse with cold water as soon as you can.

2. Hand wash gently
Use a mild, eco-friendly detergent and skip the washing machine if possible. If you must machine-wash, use a mesh laundry bag or a Guppyfriend washing bag to catch microfibers.

3. Air dry in the shade
Avoid dryers and direct sun, which degrade elasticity and color.

4. Skip fabric softeners
They can coat the fabric, reducing breathability and increasing microfiber shedding.

5. Wash less often
Swimwear doesn’t need to be cleaned after every use unless heavily soiled.

More Responsible Swimwear Brands

If you're in the market for new swimwear and want to make a more thoughtful purchase, here are a few brands doing it better:

Reformation

Chic, flattering, and made with ECONYL® — Reformation's swimwear offers a balance of style and sustainability. Plus, they’re transparent about their environmental footprint.

Patagonia

A pioneer in eco-conscious outdoor gear, Patagonia’s swimwear is made from recycled materials, and the company is vocal about the need to tackle microplastic pollution. They're also leaders in repair and reuse.

Lilja the Label

This Nordic brand creates beautiful, minimalist swimwear using ECONYL® and focuses on small, mindful production runs. Their pieces are made to last — and be loved.

Underprotection

Certified B Corp and GOTS-certified, Underprotection combines recycled materials with ethical manufacturing and a strong focus on transparency. Their swimwear is both pretty and purpose-driven.

Conscious Choices Go Beyond Fabric

Sustainable swimwear is about more than just the fabric, it’s about buying less, choosing well, and taking care of what you already have. It’s also about asking brands hard questions, supporting companies that care, and understanding the environmental impact of every garment we wear, even something as small as a bikini.
Swimwear might never be perfectly sustainable, but by being informed and intentional, we can reduce harm and help protect the waters we love to swim in.

Your Guide to Sustainable Swimwear