The Plastic Your Activewear Brand Will Never Mention

The Plastic Your Activewear Brand Will Never Mention

A major activewear brand announces it has removed polyester from its leggings. The press release uses the word sustainable eleven times. The campaign imagery features open fields and natural textures. The price goes up.

Check the care label.

Elastane: 18%.

Spandex — also sold under the brand names elastane and Lycra — is a synthetic polyurethane fiber derived from petroleum. It is, by any material definition, plastic. Its presence in the care label of a garment marketed as having eliminated synthetic materials is not an oversight. It is the structural reality of the activewear category, and it is the variable the greenwashing conversation almost never reaches.

Why Spandex Cannot Be Removed

Workout bras and compression leggings as a garment category did not exist before spandex was invented. The mechanical properties that define performance activewear — four-way stretch, elastic recovery, compression, shape retention after repeated wear — are properties of synthetic polyurethane. They are not properties of cotton, wool, linen, or any other natural fiber currently available at commercial scale.

Spandex typically represents between 2% and 20% of a garment's fiber content by weight. Its functional contribution is disproportionate to its volume. Without it, the garment category as it currently exists ceases to perform its primary function. This is not a brand choice or a sourcing preference. It is a material science constraint that applies equally to the most sustainable activewear brand on the market and the least.

When a brand removes polyester from its leggings, it has made a genuine improvement. Polyester is the dominant synthetic fiber in activewear by volume, and reducing it reduces the primary source of microplastic shedding in the garment. That improvement is real and worth acknowledging.

It is not the same as removing plastic. The spandex remains. The marketing copy does not always make that distinction clear.

The Biological Consideration

The case for addressing spandex is not limited to its petroleum origin. Even at low percentages, elastane in a natural fiber blend has a documented effect on the garment's microfiber release profile.

Peer-reviewed research on cotton-elastane blended fabrics found that increasing elastane content from 2% to 8% more than doubled microfiber release per square centimeter during laundering. The synthetic fibers shed independently of the natural fibers surrounding them. The organic cotton in the blend does not absorb or offset the elastane's contribution to microplastic release. A small spandex percentage does not mean a small biological contribution — particularly in garments worn against the skin for extended periods under heat and friction.

The HPG axis, the body's hormonal regulatory system governing reproductive function and mood, is sensitive to endocrine-disrupting compounds associated with synthetic polymer degradation at low, chronic doses. This is not acute toxicology. It is the biology of cumulative exposure — the precise exposure model of daily activewear use.

What Is Actually Coming

The solution to the spandex problem is not the elimination of elastic stretch from performance apparel. It is the replacement of the petroleum source with a plant-derived one. That replacement is not a research project. It is a manufacturing schedule.

Hyosung, the world's largest spandex manufacturer, has invested $1 billion in a facility in Vietnam producing certified bio-based spandex derived from sugarcane. Production commences in Q2 2026 with initial annual capacity of 50,000 tons, scaling to a target of 200,000 tons annually. WWD The mechanical performance of the bio-based fiber is equivalent to conventional spandex — same stretch, same recovery, same compatibility with existing manufacturing processes.

LYCRA is collaborating with Qore, a joint venture of Cargill and HELM AG, to produce spandex using 70% bio-derived ingredients from rain-fed dent corn, with a preliminary lifecycle assessment indicating a 44% reduction in CO2 emissions versus conventional spandex. Formula4media

Yulex, the company behind natural rubber wetsuits for Patagonia and O'Neill, introduced YULASTIC in 2025 — a fine natural rubber filament harvested from the Hevea brasiliensis tree as a plant-based elastane alternative. Yulex

PANGAIA became the first brand globally to incorporate the most advanced bio-based elastane into a commercial activewear range in 2025, using Hyosung's regen BIO Max fiber with third-party verified lifecycle data.

The infrastructure for plant-derived elastic stretch is being constructed at industrial scale right now. The timeline is not speculative. It is a production schedule with a capital commitment behind it.

What Bio-Based Spandex Does and Does Not Solve

It is worth being precise about what the transition to bio-based elastane accomplishes and what it does not.

Bio-based spandex reduces the fossil fuel input required to manufacture the fiber. It lowers the carbon footprint of production. It begins to address the petroleum dependency that makes conventional spandex an environmental liability at scale.

What bio-based spandex does not automatically resolve: the microfiber release profile during wear and laundering. A bio-derived polyurethane fiber still sheds particles during mechanical stress. Whether those particles carry a different biological profile than petroleum-derived spandex microfibers is a research question the peer-reviewed literature has not yet fully answered. The origin of the raw material changes the supply chain story. It does not necessarily change the dermal exposure model during wear.

This is a distinction worth maintaining as bio-based spandex enters consumer marketing. The renewable sourcing claim is legitimate and meaningful. A claim that bio-based spandex eliminates the biological concerns associated with synthetic fiber exposure would require evidence that does not yet exist.

The Honest Version of This Conversation

What an honest plastic-free activewear claim looks like today: the brand has removed the polyester it could remove. The spandex remains because no commercial alternative existed at scale when the garment was designed. The improvement is real. The limitation is structural, not ethical.

What it will look like within two to three years, as Hyosung's 200,000-ton sugarcane facility reaches capacity and LYCRA's corn-derived fiber completes its production conversion: bio-derived spandex will be available at commercial scale, at price parity with conventional alternatives, with equivalent mechanical performance and a significantly reduced fossil fuel footprint.

The category is changing on a real timeline with real capital behind it.

In the interim, the consumer navigating activewear marketing faces a simple standard: the care label is the document that matters. If elastane, spandex, or Lycra appears anywhere in the fiber content list, the garment contains a synthetic component regardless of what the marketing copy emphasizes. That is not a reason to avoid the garment. It is information needed to understand what is actually touching your skin.

Fabrics Vetted examines the biological interface between apparel and the human body. FabricsVetted.com

References

1. Hyosung. Bio-based spandex from sugarcane, Vietnam facility commencing Q2 2026, 50,000-ton initial capacity scaling to 200,000 tons. WWD, April 2024.

2. Hyosung. regen BIO Max elastane: 27% lower carbon footprint, 82% less ozone depletion vs conventional spandex. Sourcing Journal, June 2025.

3. LYCRA Company and Qore. Bio-derived LYCRA fiber using 70% bio-based ingredients from corn. 44% CO2e reduction preliminary LCA. Formula4Media.

4. Yulex. YULASTIC plant-based elastane from Hevea brasiliensis natural rubber. Yulex.com, March 2025.

5. PANGAIA. First brand to incorporate regen BIO Max elastane into commercial activewear range. Hyosung blog, 2025.

6. ScienceDirect. Investigation on microfiber release from elastane blended fabrics. 2023.

7. Sustainability Directory. Bio-based spandex scales commercially. December 2025.

8. Silver Sea Apparel. TENCEL and regen bio-based spandex in US activewear. silverseaapparel.com.