Ever wondered what exactly makes your socks fit tightly? Or form-fitting outfits so stretchy, snug, and comfortable? It's a material we call polyurethane. Now polyurethane might not ring a bell, but we bet spandex, elastane, or the more popular lycra does.
If you like form-fitting clothes, you are not the only one; stretchy clothing is everywhere. In fact, more than half of the world’s clothing demand is for soft, stretchy synthetic fabric. From undergarments and socks to sportswear, swimwear, and motion capture suits, elasticity is a requirement for comfort.
Lycra fabric is a popular stretch fabric choice. But we know that popularity does not always indicate sustainability. In this article, we take a look into the details of lycra and find out just how sustainable or unsustainable it is.
Lycra fabric is an elastomeric polyurethane fiber, the same material as spandex or elastane fabric. Lycra, itself, is a brand name that the DuPont Corporation coined for spandex4. Other brand names for spandex include Vyrene, Spandelle, and Numa. We find spandex in sportswear, swimwear, underwear, and socks most times, but it is applied to a large variety of clothing as well.
Elastane fibers are incredibly stretchy and can reach 500 to 610 percent of their original size with ease when stretched. They snap back into their original size in an instant. Lycra and all kinds of spandex do not do well with extreme heat and will melt at about 250 degrees Celsius. Spandex fabric absorbs very little moisture and so works great for breathable moisture-wicking clothing.
Lycra fibers are white and have a dull luster but take to dye easily. However, prolonged exposure to light or heat will cause the colors of lycra fabric to fade or adopt a yellowish hue. Contact with chlorine bleach will also cause elastane fabric to yellow. It is common to find lycra fibers wrapped with other fibers like nylon.
They produce spandex or elastane fabric using polyurethane. At least 85 percent of spandex is polyurethane by weight.
Spandex fibers are segmented polyurethane; they owe much of their elasticity to this unique structure. The segments consist of alternating flexible and rigid parts that react differently to being stretched3. The rigid segments tend to cluster, and the flexible segments act as springs connecting the rigid parts. That is why spandex fabrics are extremely elastic but do not lose elasticity after repeated stretching like rubber does.
They make the rigid segments from Methylene diphenyl isocyanate (MDI) and ethylene glycol or 1,4-butanediol. They create flexible parts with MDI and polyether or polyester glycol.
They manufacture spandex with different methods; melt extrusion, solution dry spinning, reaction spinning, and solution wet spinning. In all these methods, the first step is to form a pre-polymer from monomers and then further react it with other elements like diamine acid. Solution dry spinning is the most used method, accounting for over 90 percent of the world’s spandex supply1.
In the solution dry spinning process, they react the prepolymer with diamine acid and mix the resulting substance with a solvent to thin it. Then they load the thinned solution into a fiber production cell. The fiber production cell then begins to spin and forces the solution through a spinneret. The filaments pushed out to the other side of the spinneret are exposed to heated nitrogen and solvent gas so that they solidify.
After they cover the spandex yarn with other kinds of fibers, they send it to the mill. In the mill, spandex is often interwoven with modal, cotton, nylon, and polyester to produce fabrics commonly used in clothing. Because of how much spandex stretches, they must weave it with a particular yarn feeder.
In 1938 DuPont invented nylon, a breakthrough in synthetic fibers that gave rise to the first fully lab-made fabric. This invention spurred many others, lycra inclusive. The advent of World War II intensified the need for new fibers as rubber, nylon, and silk were mainly diverted to aid the war efforts. Natural rubber, used in undergarments and girdles, became an important resource used to make tires to support the war efforts.
After years of collaborative scientific research, the breakthrough for a synthetic fiber that could replace rubber came from Dr. Joseph Shivers in 1958. He was a chemist working for the DuPont Corporation at that time. He named the superelastic new fiber, ‘fiber k,’ upon invention, but the company sold the product under the brand name ‘Lycra.’ Others called it spandex or elastane.
Lycra’s elasticity of up to 500 percent of its original size, durability, and strength made it possible to create soft, sheer, and lightweight underwear. It had resistance to stains from oils, lotion, and perspiration. These qualities made it a significant improvement over rubber which was constricting, heavy, hot, and lost elasticity over time.
Spandex started as just swimwear and underwear until 1968, when the French men’s ski team wore ski suits. The team won the most medals, attributed to their lycra uniform. Another highlight in lycra’s history is that it was one of the 21 layers of Neil Armstrong’s spacesuit as he took his first step on the moon in 1969.
Spandex has primarily replaced natural and synthetic rubber in the textile industry. Apparel manufacturers commonly use spandex fabric for socks, sports bras, underwear, swimsuits, yoga pants, and most form-fitting garments. They make outfits that must fit tightly, like motion capture suits with spandex. Lycra is more popular with women than with men, so we find that clothing brands for women use it more. We can also find spandex yarn used as a material for knitting.
Elastane makes fabrics like cotton, hemp, polyester, and wool stretch and makes them more comfortable to wear and form-fitting. It is not very common to find garments made entirely out of elastane fibers because they are more costly than other synthetic fabrics. The common practice is to mix a certain percentage of spandex, say 5 to 10 percent, with different fabrics.
There are two different types of spandex yarns, one is a naked filament, and the other is wrapped in other kinds of fibers. The naked filament spandex is not skin-friendly and may cause allergic reactions, especially in people with sensitive skin.
In contrast, the wrapped spandex is better and is more popular than the naked version. They use it for intimate clothing like socks, underwear, and swimwear. It is the best type of spandex for sports bras, yoga pants, motion capture suits, and sportswear in general. Spandex in itself provides no insulation, and therefore in winter sports applications, it's combined with other fabrics.
No, there are no material differences between spandex, elastane, and lycra, technically they refer to the same material. Elastane and spandex are generic names for polyurethane fiber, they are synonymous, but the name spandex is used predominantly in the USA. In contrast, the rest of the world uses the name elastane. DuPont gave the name Lycra to its own brand of spandex.
Fun fact; spandex is ‘expands’ spelled backward. Of course, variations in manufacture and use can result in varying qualities and applications of the same material type.
Lycra has the same environmental impacts as other synthetic fabrics. Below we explore the impacts of lycra fabric in terms of production, raw material, and so on.
They make spandex from fossil fuels, just like any other synthetic fabric. The problem here is that fossil fuels are non-renewable resources. Lycra’s dependence on fossil fuels is unsustainable.
Presently production of synthetic fabric like lycra consumes 1.35 percent of the world's oil resources. That is more than Spain's annual oil consumption. Experts predict that if the current textiles consumption trend continues, the synthetic fabric will climb to 73 percent of textile production by 2030, which means more oil consumption.
The unsustainability of lycra’s fossil fuel use lies in the fast fashion supply chain that has taken over the apparel industry. Fossil fuels are a limited and precious resource; using them to make clothing that will end up in landfills within a year or six months is such waste. About 85 percent of all textiles produced annually, including lycra fabric, end up in landfills every year.
Extracting and processing fossil fuels is a highly polluting activity, and in 2020, the world produced up to 59.7 million tonnes of virgin fossil fuel-based fabrics2. The apparel industry is responsible for 10 percent of global greenhouse emissions and synthetic fabric production contributes a larger share of this amount due to their dependence on fossil fuels.
When we add the environmental cost of fossil fuel energy production to raw material sourcing costs, lycra has a big fat carbon footprint.
The process of making spandex fabric is chemically intense. They commonly use synthetic dyes to color lycra fabrics. Simple investigations often implicate waste dye in water pollution in the areas surrounding textile factories.
They source a percentage of fossil fuel products used in synthetic fabric production from the abundant gas produced by fracking. Fracking is a highly polluting activity that releases large quantities of methane gas into the atmosphere. Methane is a potent greenhouse gas that contributes extensively to global warming.
In addition to greenhouse gas emissions, fracking uses a lot of toxic chemicals and other harmful substances. Many of these chemicals are endocrine disruptors and carcinogens.
Lycra is a plastic-based fabric, and plastic is resistant to microorganisms that break down materials. Plastics and plastic-based fabrics like spandex will not break down into organic matter and are therefore non-biodegradable. The inability of plastics to decay means that they will be sitting in landfills for a long time, possibly hundreds of years.
That lycra clothing remains intact in a landfill for years means it is taking up prime space and forcing us to allot more land resources for landfills. After years of degradation by sunlight and oxygen, lycra fabric will break into extremely toxic microplastics. As microplastics are incredibly mobile, they can end up in unseemingly places like in our tap water.
Like most natural and synthetic fabrics, Lycra fabric sheds microfibers, especially when we wash them. While natural microfibers will decay and turn into valuable organic matter to the soil and microorganisms, microfibers from synthetics like lycra remain in the same chemical state. We call them microplastics, and over half a million tonnes of them enter the ocean every year.
Microplastics are a menace to marine life and human health. Microplastics are a magnet for toxins, and fish swallow these toxic microplastics. Often, these fish end up on our plates and get into our bodies. Wind and rain also carry microplastics around, and they can end up virtually anywhere. No place is safe.
Recycling lycra is quite tricky because it is usually interwoven with other fibers to produce fabric blends. Recovering it from within those fabric blends is a complex task. They add lycra to fabrics of different origins in very little quantity, so getting enough post-consumer waste lycra to make recycling economically viable will take a long time.
Also, recycling lycra will still consume energy often provided by fossil fuels. So it is not entirely carbon-free.
Resistant to oil and perspiration: Oils from cosmetics and body care products do not damage lycra easily. Perspiration will not damage lycra either.
Shape retention: lycra’s resilient stretchiness is one reason many people like it. It always bounces back to its original form.
Elasticity: lycra adds elasticity to wool, cotton, and others. It gives those fabrics better shape retention, durability, and versatility.
Resistant to mildew: lycra is resistant to microorganism's activity. It has high resistance to mildew and fungi that cause mold. Lycra also resists damage from insects and pests.
Wrinkle-resistant: Lycra does not require much in the way of ironing; it is easy to maintain and resistant to wrinkles and pilling.
Sensitive to heat: lycra underwear, socks, or any garment containing lycra is highly susceptible to heat damage. Exposing clothing made with 100 percent lycra to heat ruins the fabric because it will fuse. Washing the fabric in hot water, machine drying, or using iron can lead to permanent damage.
Slickness: Lycra fabric is so slick, making it difficult for it to create friction. There is a high chance of you slipping off plastic or metal chairs if you wear a garment made only with lycra.
Does not absorb water: Lycra does not absorb water, so a pure lycra garment is not ideal for sweat-inducing activities such as exercising. It can snag bad odor within the garment can lead to a skin infection.
Allergenic: clothes made with naked lycra fiber are prone to causing skin allergies because spandex is made with harsh petrochemicals.
We highly recommend warm or cold water for washing Lycra fabric. Ideally, the temperature should not be over 40 degrees celsius. Gentle hand washing is best for lycra clothes, especially sheer underwear and socks. You can safely wash delicate lycra clothing by first placing it in a mesh bag before putting it directly inside the machine. Then set the washing machine to a slow spin.
You should not wash Lycra fabric with highly acidic or alkaline detergent, and mild detergents are better. If there are stains on the fabric, you should wash it immediately. We do not advise using chlorine bleach as it will damage the fabric.
It is best to air dry lycra fabric, but you should not dry it under direct sunlight as heat and light can cause it to fade. You don't need to iron lycra fabric as it is already wrinkle-resistant. But if you must iron lycra clothing, do this with the lowest possible heat to prevent the fabric from fusing.
Some brands that use synthetic fabrics claim to do so sustainably but are often unable to provide information and evidence of such sustainable practices. And even the best sustainable practices do not eliminate the fact that they make spandex or lycra from a nonrenewable natural resource. Neither does it change the fact that lycra is not biodegradable.
Here are a few popular brands that use lycra.
This fast-fashion clothing brand uses mostly synthetic fabrics. In 2017, the Los Angeles Times investigation revealed that a factory worker makes up to 700 Forever 21 shirts a day. The brand has a reputation for unfair labor and has been sued for violating labor laws on multiple occasions.
Although the brand says it uses completely recyclable paper and plastic bags and donates $0.05 to the American Forests Association every time a customer uses their own bag to carry their purchase. They leave a lot undone in the way of sustainability. You can find up to 35 percent spandex in activewear made by Forever 21.
The H&M brand is an extremely popular fast-fashion brand. They make clothes for men and women; releasing no less than 12 collections a year, they churn out millions of clothes every year. They had previously come under fire for unsustainable practices such as unpaid wages and using harmful chemicals such as phthalates in their products. And now, the brand is trying to make amends.
H&M has pledged to use only sustainable or recycled materials by 2030 and become climate positive by 2040. Presently, however, the brand uses as much as 21 percent elastane in its clothes
Zara is one of the earliest fast fashion companies. The brand is famous for touting its ability to finish the design to garment process in 15 days. It has kept that promise and shows no sign of slowing down. Today, Zara produces up to 24 collections in a year, and you commonly find about 5 percent elastane in their clothing.
The brand has promised to switch to using only cotton and polyester as they believe both are recyclable and, therefore, sustainable. They also intend to reduce and offset all carbon emissions. These promises, however, will have to wait until 2040 to become a reality.
Polyester remains the more popular choice of synthetics; it accounts for over 65 percent of fabrics in the textile industry. This means that polyester draws from fossil fuels the most of all synthetic fibers. It takes about 342 million barrels of oil to manufacture enough polyester for the world for one year5. So polyester may account for a higher percentage of microfibers than lycra.
Both polyester and nylon fabric are non-biodegradable and contribute to plastic pollution. However, polyester has a higher recycling rate compared to lycra fabric. Recycled polyester was about 8.4 million tonnes in 2020, while the infrastructure for recycling lycra remains largely underdeveloped.
Lycra and leather are both high-demand fabrics, and each has its own issues. Lycra is a fossil fuel-based product, but they source leather from animals. Natural leather is controversial, with many animal rights activists voting against it. Veganists got their wish for non-animal leather in faux leather, which we also call vegan leather.
While vegan leather avoids animal cruelty allegations, they make it from polyurethane or polyvinyl chloride. Both materials are plastics that have the same environmental consequences. The point is that when it comes to environmental consequences, vegan leather is not much better than spandex.
Cotton is the most popular natural fabric they source from plants. Compared to spandex, it has merits because it is biodegradable and does not use fossil fuel as raw material.
However, cotton, or more precisely conventional cotton, consumes a lot of toxic chemicals in the form of pesticides and herbicides during the raw material growing stage. Also, it is a water-intensive crop that is grown monoculturally.
Both elastane and conventional cotton have serious environmental consequences, but we have the alternative of growing sustainable organic cotton. lycra, however, despite the best attempts at eco-friendliness, still remains a fossil fuel-based fabric
Spandex and nylon are both stretchy, but spandex is way more stretchy than nylon. Nylon’s strength makes it extremely valuable, and the elastic property of spandex is its best quality. Both fabrics have a high demand placed on them.
Crude oil is the source of raw material for nylon fabric and spandex, which makes them non-biodegradable. However, since manufacturers usually blend spandex with another fabric and you will typically find spandex in small portions in clothing. Most stretchy clothes have just 5 to 10 percent.
Lycra is an important fabric in the textile industry but what’s more important is the environmental effect it has. If we consider the environmental costs carefully, we will find that we are paying a hefty price for the convenience of spandex. You can support sustainability by minimizing your consumption of spandex or cutting it off completely.
Alamm SMM et al. (2020) Reviewing the production process, physical and chemical properties of spandex fibers.
Textile Exchange (2021) Preferred fiber and materials.
Encyclopedia Britannica. Polyurethanes
Encyclopedia Britannica. Spandex
Jen’s a passionate environmentalist and sustainability expert. With a science degree from Babcock University Jen loves applying her research skills to craft editorial that connects with our global changemaker and readership audiences centered around topics including zero waste, sustainability, climate change, and biodiversity.
Elsewhere Jen’s interests include the role that future technology and data have in helping us solve some of the planet’s biggest challenges. She’s also busy researching and exploring technology applications for product development for a changing world.