If you pull a pair of yoga pants from the rack of any sports brand, the label will almost definitely tell you that they are made of 78% polyester, 22% elastane, or a combination of those materials. The chemistry remains constant despite the quantities changing. The component that gives contemporary sportswear its second skin sensation is elastane, which is also marketed as spandex or Lycra, depending on the chemical manufacturer. It springs back without deforming after stretching 500% of its initial length. That is not something that occurs naturally. And that has been the issue.
For years, the fashion industry has been learning how to discuss sustainability while subtly excluding elastane. The marketing focus is on organic cotton. The certification logos are awarded to recycled polyester. However, blended stretch fabrics, which are made of cotton or polyester and include only a small amount of elastane, are still mostly outside the circular economy. The catch is in the merging itself. The final fabric is difficult to separate because elastane and polyester form a molecular link during production. Globally, less than 1% of mixed clothing is recycled into new apparel. The remainder is disposed of in landfills or incinerators, where it breaks down and releases microplastics.
The fact that spandex is so good is what makes this issue persistent. Genuine snap-back elasticity, wash after wash, year after year, is something that no plant fiber in nature has ever achieved on a commercial scale. It is also incredibly durable and inexpensive to create. The intricacy of the endeavor explains why, until recently, no one had succeeded in creating a bio-based counterpart, despite decades of research efforts.
That is beginning to change. In 2025, Yulex, the firm that makes natural rubber-based wetsuits for companies like Patagonia and O’Neill, unveiled YULASTIC, a fine natural rubber filament that comes from the Hevea brasiliensis tree and is intended to serve as a direct substitute for elastane in knitted garments. It comes from plants, is biodegradable, and has previously been tested by a number of sportswear companies.
In other news, Hyosung, the South Korean fiber powerhouse responsible for the Creora spandex brand, is increasing the amount of bio-based 1,4-butanediol produced through sugar fermentation. This substance is one of the main chemical components of spandex, and obtaining it from corn sugars instead of crude oil significantly reduces the carbon footprint of production without affecting the fiber’s performance. By 2026, the business hopes to produce 200,000 tons of bio-based spandex each year.
A contrasting perspective is provided by Asahi Kasei’s ROICA V550, a biodegradable elastane that has obtained a Cradle-to-Cradle Certified Material Health Certificate and breaks down about 50% in 24 months under composting conditions. It modifies the fiber’s final destination rather than the source of the chemical.
Although the end-of-life narrative is significantly better than traditional spandex, a garment created with ROICA V550 still creates microplastics during washing, which is a real drawback. Additionally, researchers at universities like MIT are creating mono-material elastic yarns by employing a single polymer family for both the protective outer sheath and the elastic core. This allows the entire structure to be meltable and respinnable without the need for chemical separation. Theoretically, those clothes could be recycled endlessly.
