Microplastic shedding from synthetic garments is one of the more thoroughly documented concerns in the textile and environmental science literature. Elastane, as a synthetic polyurethane fiber present in virtually all fitted activewear, is part of that conversation. The question is how significant its contribution is relative to the other synthetic fibers it typically shares a garment with.
For women choosing curated non toxic activewear, understanding exactly where the microplastic risk sits in the fabric composition is what makes the choice meaningful.
What microplastic shedding is
During washing, mechanical agitation causes textile fibers to break off from the fabric surface. For synthetic fibers, these shed particles are synthetic polymer microplastics that enter the wastewater stream, pass through water treatment systems, and accumulate in aquatic environments and soil. Research by Browne et al. published in Environmental Science and Technology (2011) documented the accumulation of synthetic microplastic fibers on shorelines globally and established laundering of synthetic garments as a primary source.
A subsequent study by Napper and Thompson published in Marine Pollution Bulletin (2016) quantified microplastic shedding from specific fabric types and found that acrylic fabrics shed the highest number of fibers per wash, followed by polyester-cotton blends and polyester. The research established that the volume of shedding is correlated with fiber type, fabric construction, and the percentage of synthetic fiber content. For the full picture on microplastics in activewear, including which fabrics shed the most and how to reduce exposure, the dedicated guide to microplastics in activewear covers the research comprehensively.
Does elastane specifically shed microplastics?
Yes. Elastane is a synthetic polyurethane polymer, and like other synthetic fibers, it sheds polymer particles during mechanical washing. The particles shed are polyurethane microplastics.
The relevant context is proportion. In a typical activewear blend, elastane makes up 5% to 20% of the fabric by weight. The majority of synthetic microplastic shedding from a predominantly synthetic garment, a nylon and spandex blend for example, comes from the majority fiber, which is nylon, rather than from the elastane component. At 8% elastane in a 92% TENCEL Lyocell blend, the elastane's contribution to total fiber shedding is small in absolute terms, and the majority of fiber shed is cellulose-based TENCEL Lyocell rather than synthetic polymer.
Why the surrounding fiber composition matters
A garment that is 88% polyester and 12% elastane sheds primarily polyester microplastics, with a smaller elastane contribution. A garment that is 92% TENCEL Lyocell and 8% elastane sheds primarily cellulose fibers, with a smaller elastane contribution.
This distinction matters because cellulose fibers break down in aquatic and soil environments differently than synthetic polymer fibers. A study published in PLOS ONE by Zambrano et al. (2019) compared the biodegradability of cotton, polyester, and blended fabrics in aquatic environments and found that cotton fibers degraded significantly faster than polyester fibers under the same conditions. TENCEL Lyocell, as a cellulose fiber, behaves similarly to cotton in this regard. Synthetic polymer microplastics, including polyester and elastane particles, persist in the environment significantly longer.
For women who are concerned about the microplastic contribution of their activewear, the most effective lever is the primary fiber composition of the garment rather than the elastane percentage specifically. Reducing the overall synthetic fiber content from 88% to 8% through primary fiber choice reduces synthetic microplastic shedding more significantly than adjusting the elastane percentage within a predominantly synthetic garment.
Can microplastic shedding from elastane be reduced?
Several approaches reduce total microplastic shedding from synthetic activewear, though none eliminate it entirely. Washing in a Guppyfriend washing bag, a fine mesh bag designed to trap shed fibers, captures a significant portion of shed fibers before they enter the wastewater stream, according to independent testing by the Fraunhofer Institute (2017). Washing on shorter, gentler cycles reduces mechanical agitation and proportionally reduces shedding. Washing less frequently also reduces cumulative shedding, though this needs to be balanced against hygiene requirements for workout clothing.
For TENCEL Lyocell blends with small elastane percentages, the total synthetic microplastic shedding is already reduced by the primary fiber choice. Additional measures like mesh washing bags further reduce the environmental impact of the elastane component.
The practical answer
Elastane sheds microplastic particles during washing, as do all synthetic fibers. At low percentages in a natural fiber blend, its contribution to total microplastic shedding is proportionally small. The more significant factor for total synthetic microplastic output from activewear is the primary fiber composition of the garment rather than the elastane content specifically.
Bellissima's Sempre Leggings and bras use 8% spandex (elastane) in a 92% TENCEL Lyocell blend. The synthetic microplastic shedding from this composition is primarily a function of the 8% elastane content, since the TENCEL Lyocell majority fiber sheds cellulose particles rather than synthetic polymer particles. That is a meaningfully different environmental profile from a predominantly synthetic activewear garment. For more on the toxicity profile of elastane itself, whether elastane is toxic covers the full picture. The related question of whether spandex is toxic approaches the same evidence from that angle. For the polyester comparison specifically, whether polyester sheds microplastics documents the research on the most prevalent synthetic fiber in activewear.
Sources
Browne, M.A., et al. (2011). Accumulation of microplastic on shorelines worldwide: Sources and sinks. Environmental Science and Technology, 45(21).
Napper, I.E., and Thompson, R.C. (2016). Release of synthetic microplastic plastic fibres from domestic washing machines: Effects of fabric type and washing conditions. Marine Pollution Bulletin, 112(1-2).
Zambrano, M.C., et al. (2019). Microfibers generated from the laundering of cotton, rayon and polyester based fabrics and their aquatic biodegradation. PLOS ONE, 14(9).
Fraunhofer Institute for Environmental, Safety, and Energy Technology. (2017). Guppyfriend washing bag microplastic testing. Fraunhofer UMSICHT Technical Report.
Lenzing AG. (2023). TENCEL Lyocell fiber sustainability and production data. Lenzing Sustainability Report.
