The Best Nontoxic Bikinis of 2026

Nontoxic Bikinis: What’s Actually Possible

When it comes to “nontoxic” bikinis, this is one of the hardest categories to get right.

Most swimwear is made from synthetic materials like polyester, nylon, and elastane, which are petroleum-based fabrics. These materials are used for a reason. They are durable, stretchy, quick-drying, and able to withstand saltwater, chlorine, and sun exposure. Natural fibers simply do not perform the same way.

Synthetic fabrics can shed microplastics, rely on chemical dyeing processes, and often include finishes or treatments that are not disclosed on labels. Even when brands use recycled materials, it does not change the fact that the base material is still plastic.

At the same time, bikinis are inherently performance-driven. They need to stretch, hold shape, and function in water. That makes it very difficult to create a truly “nontoxic” option without tradeoffs.

Where the Industry Is Shifting

Most brands that position themselves as “clean” are still using synthetics, just in slightly improved forms.

This includes:

• Recycled nylon (like Econyl)

• Recycled polyester

• OEKO-TEX certified fabrics

These are better options, but they are not truly non-toxic. They are still plastic-based materials.

What’s more interesting is the small group of brands working with natural fibers like hemp and organic cotton.

These materials:

• Are plant-based instead of petroleum-based

• Reduce microfiber pollution

• Tend to be more breathable and skin-friendly

For example, brands like Natasha Tonic are using organic hemp and cotton blends designed specifically for swimwear.  

The tradeoff is performance:

• They absorb water instead of repelling it

• They dry more slowly

• They require small amounts of elastane to function

So again, this is not perfect. It’s just a different set of tradeoffs.

The Best Options Right Now

Organic Cotton + Hemp (Closest to Nontoxic)

These are the closest options to what most people are actually looking for when they say “nontoxic.”

• Isole & Vulcani

Small European designer focusing on more natural, minimal fiber compositions and slower production. Likely blends of natural fibers with limited synthetics for structure.

• BeachCandy Organics

Uses organic cotton and hemp blends, designed to reduce reliance on synthetic swim fabrics while still maintaining some stretch and wearability.

• Natasha Tonic

One of the most established brands in this space. Uses certified organic hemp and cotton, which are naturally breathable, UV-resistant, and designed to reduce microfiber pollution.  

• Pure Earth Collection

Focuses on more natural and lower-impact materials with an emphasis on reducing synthetic exposure, though still may include minimal stretch fibers.

OEKO Certified + Synthetic (Cleaner, Not Nontoxic)

This is where the majority of “clean swimwear” brands fall.

• Narah Soleigh

Uses elevated synthetic swim fabrics that are OEKO-TEX certified. Still primarily nylon or polyester-based.

• YouSwim

Uses OEKO-TEX certified fabric (Versoform™) designed to reduce harmful residues and ensure safer processing, while still being fully synthetic.  

• Quince

Uses more affordable synthetic swim fabrics that are OEKO-TEX certified, but still primarily petroleum-based materials.

My Take

For me personally, I lean toward natural fibers when possible, especially for pieces I’m wearing for longer periods of time.

But I also understand why synthetic fabrics dominate this category. They perform better, last longer, and are more functional in water.

So this is less about eliminating everything and more about understanding your options.

The reality is:

→ Truly nontoxic swimwear is still limited

→ Better options do exist

→ And the biggest shift right now is moving away from plastic where possible