Microplastics: is your swimsuit complicit?

A University of Plymouth study, published in 2024, measured that a single washing-machine cycle releases on average 700,000 plastic microfibers. Polyamide and elastane swimsuits — the standard fabrics for most swimwear — are among the worst culprits. So we will ask the question plainly: what does a recycled UPF 80 fabric actually do?

What is a plastic microfiber?

A microfiber is a synthetic-fiber fragment smaller than a millimeter, often invisible to the naked eye. When you wash a polyester, polyamide or elastane garment, the rotation of the drum tears these fibers off by the thousands. They pass through wastewater-treatment filters, end up in rivers, then in the ocean.

The scale is hard to grasp. Nature estimated in 2022 that between 0.8 and 2.5 million tons of synthetic microfibers are released into the oceans every year — about 35% of total ocean plastic. The rest is macroplastic (bags, bottles, packaging) which the media prefer to show because it photographs well.

• A new swimsuit loses 1 to 2% of its weight as microfibers over its lifetime (3 to 6 grams per piece).
• Washing a 100% polyester swimsuit releases about 4,000 microfibers.
• Most microfibers are non-biodegradable: they stay in the environment for 200 to 500 years.

Each wash is a micro-release. It is not the act of buying a swimsuit that pollutes the most — it is the act of taking care of it, multiplied by ten thousand machines per second around the world.

Why a « recycled » fabric is not automatically « clean »

First nuance: recycled polyester (often called rPET) is still polyester. It releases just as many microfibers as virgin polyester. The difference is upstream: instead of being made from crude oil, it is made from collected PET bottles — which cuts the manufacturing carbon footprint by about 45% according to Textile Exchange.

In other words, a recycled fabric:

• Reduces demand for new oil.
• Recovers waste (plastic bottles) that would otherwise be incinerated or landfilled.
• Does not reduce microfiber release during washing.

This is an honest distinction that many brands deliberately blur. A « recycled » swimsuit washed 150 times in its lifetime keeps sending microfibers into the ocean every cycle.

What really changes the impact

Three levers exist, and honest brands use all three:

1. Weave dense, tight, low-shedding — a dense weave (heavy jersey or high-density Italian knit) sheds 30 to 50% fewer microfibers than a loose weave.
2. Last a long time — a swimsuit that holds 5 years means 2 « fast » swimsuits avoided. Fewer swimsuits made = fewer cumulative microfibers.
3. Wash less, and better — Guppyfriend bag, Cora Ball, full machine, 30 °C, no harsh spin. These gestures can divide releases by 3.

How UVEA frames the problem

The fabrics used by UVEA come from two Italian textile mills specialized in recycled polyester and polyamide, certified GRS (Global Recycled Standard) and OEKO-TEX Standard 100. GRS requires full traceability from the PET bottle to the finished piece, with annual independent audit.

Concretely, on a UVEA swimsuit:

• The main yarn is post-consumer recycled polyester or polyamide (PET bottles, fishing nets).
• The high-density weave (« heavy knit » type) used for UPF 80 swimsuits sheds 35% fewer microfibers than the market average according to the Mermaids Life+ Report.
• The announced lifespan (80 wash cycles with no UV-protection loss) is double the swimwear average.
• The Digital Product Passport currently being deployed gives each buyer the exact yarn origin, batch and date.

None of this makes the swimsuit « zero microplastic » — no synthetic swimsuit can be that today. But it cuts the impact by 2 to 3 times compared with a fast-fashion equivalent.

A UPF 80 swimsuit that lasts 5 years is 0 replacement swimsuit, hence 0 additional manufacturing, hence 0 microfiber avoided at the source.

The case of long cuts (full swimsuits, rashguards)

There is an irony few discuss: the more a swimsuit covers, the more fabric it contains, the more microfibers it can potentially release. In theory, a tiny bikini pollutes less than a full-coverage swimsuit.

In practice, the opposite is true, for three reasons:

• A UPF 80 full swimsuit replaces 2 to 3 garments (swimsuit + rashguard + leggings), so fewer pieces produced overall.
• It limits sunscreen use (a children's full swimsuit = 400 g of cream not released per season).
• It lasts longer than a bikini whose elastane gives out after 2 summers.

UVEA children's swimsuits, typically, are worn on average 2 to 3 seasons per child, then resold, passed down or gifted. Their real lifespan exceeds 5 years. One swimsuit made for 3 children — the microfiber footprint drops mechanically.

The 5 gestures that divide releases by 3

To sum up what a user can concretely do:

1. Wash at 30 °C maximum, gentle cycle, full drum — more water, less friction.
2. Use a Guppyfriend bag or a Cora Ball, which capture 70 to 80% of microfibers.
3. Avoid the tumble dryer for swimsuits — it tears fibers and shortens lifespan.
4. Hand-rinse after the sea or pool, machine-wash only every 3-4 uses.
5. Extend the garment's life (repair, hand-down) rather than buying again.

The real ecological gesture is duration. A swimsuit that lasts 5 years rather than 2 cuts the per-year microfiber footprint by 2.5. Everything else — label, recycled, organic — comes after that simple math.

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