Sustainable Fabric: Not all fabrics are created equal, especially as regards the costs of production (consumption of resources, risks to human health, resultant release of persistent contaminants, and subsequent harm to ecosystems) and the costs of disposal (product life expectancy, leaching of toxic components during decomposition, and whether some or all of the constituent materials can be recycled). Exploring these differences in detail will help us in making ethical purchases.
By Ellen Rubin
When you think about pollution and unsustainability, your first thoughts are probably oil, big business, or technology. Few people picture the t-shirt you’re wearing as unsustainable. You should…because the fashion industry is the second least sustainable in the world. Only the oil industry has a worse track record, and it is heavily intertwined with the fashion world.
Clothing manufacturing and the fashion industry are resource intensive, polluting, and wasteful. Many products are not biodegradable or recyclable and are therefore major contributors to landfills. Some fabrics score low for sustainability at every step of the process: creation, manufacturing, and disposal stages.
All is not lost, however. Clothing can be made with a very low carbon footprint, or even be carbon positive; and for every fabric need, there are more ecologically friendly options. Factors to consider when judging sustainability include: effect on the land, fertilizer/pesticide/insecticide use, and necessary water consumption. Production factors include: water and energy usage, chemical additives such asdyes, and biodegradability of the end product.
Clothing should not be considered a readily disposable purchase, although that is what it has become. Fabric accounts for 7-12% of global landfills, and that percentage is increasing yearly. In the United States 35.4 billion (82 pounds per person) pounds of fabric is added to landfills every year. That is up from 18.2 billion pounds in 1999, and 25 billion pounds in 2009. Many people think that by donating your clothing, you avoid this waste. Unfortunately, 84% of donated clothing goes straight to landfills. While recycled garments can be part of the solution, it is much better to simply reduce our consumption and choose our fabrics more wisely.
Sustainable Fabric: The Complete Breakdown
Greatest Sustainability: Hemp & Linen
The most ecologically responsible fabrics are linen and hemp. They may be more expensive and harder to find than other fabrics, but they provide value for the investment. Both fabrics are extremely durable. In fact, they improve with age – washing makes them both stronger and softer. They can be worn year-round – keeping you cool in summer through moisture-wicking, and warm in winter by retaining heat.
Flax (the plant used to make linen) and hemp both thrive in poor soil and a variety of climates where few other plants will grow. They require no fertilizer, insecticide, or pesticide use. The entire plant can be utilized for a variety of purposes including food, medicine, paper, building, and insulation products. They are plants that have been used for thousands of years and whose cultivation and processing has changed little over time.
Hemp fabric is a favorite around the world, although the United States has only recently passed laws making it legal to once again grow as an industrial crop. Farming hemp is actually carbon positive. Because a large number of hemp plants can be grown in a very small space, less land is needed and 70% of the nutrients are returned to the soil as lower-growing leaves decompose before harvest. Hemp removes 1.63 tons of CO2 from the atmosphere per ton of growth.
While hemp will happily grow in poor soils with no added fertilizers, pesticides or insecticides, and doesn’t require extensive amounts of energy or chemicals to process, it does sometimes require minimal irrigation. It is also not colorfast, so unless harsh chemicals are used, hemp clothing doesn’t come in vibrant colors. However, it is readily available undyed or in muted tones, often using natural dyes. It provides natural UV protection and is mold-resistant. Because of hemp’s inherent qualities and lack of chemical use throughout processing, hemp is a good choice for people with skin sensitivities.
Hemp is often used to create clothing that would ordinarily be made of cotton. Some of the advantages that make hemp more sustainable than cotton are:
- 3 times the tensile strength of cotton
- For each 2.2 pounds of fabric manufactured, hemp requires 700 gallons of water compared to cotton’s 7,000 gallons
- Hemp yields 2-3 times more fiber per acre than cotton
Flax is a fast-growing member of the grass family – only a couple of months are required from planting to harvest. It can absorb a great deal of moisture and is bacteria-resistant. Wearing linen reduces solar radiation exposure by half.
Processing flax fibers into linen threads uses a system called retting. Some processes are more sustainable than others – dew retting is the most sustainable. Enzyme and water retting require increased water usage and increase the likelihood that potentially-hazardous chemical compunds can leak into surrounding water systems.
Linen is not naturally white, so if you purchase white linen, intensive bleaching was necessary. It is more sustainable to choose natural colors such as ivory, ecru, tan or gray.
Cotton: Natural, But Not Necessarily Sustainable
Cotton fabrics are the second most common fabrics used in the fashion industry, next to polyester. The types of clothing made are similar to linen and hemp, but far greater resources are needed to grow and produce cotton clothing.
Cotton is known as “the dirtiest crop on earth” because it requires more chemical inputs, water, and land than any other crop. 2.5% of all agricultural land is devoted to cotton production. Unfortunately, 2/3 of the harvest is not usable for fabric production and is pure waste. Unlike linen and hemp, extensive chemical use is required for growth: 16% of all pesticide, 25% of all insecticide, and 6.8% of all herbicide use worldwide is attributable to cotton production. Farmers continually grow cotton on the same fields (in what’s known as monoculture), with the result that the soil becomes depleted of vital nutrients, increasing the necessary usage of chemical fertilizers to produce the same quantity of cotton.
One of the least sustainable aspects of cotton is its water requirements. 3% of the world’s water is used to irrigate fields. So much has been diverted that deserts have been created from once large water sources (desertification). The Aral Sea, located between Kazakhstan and Uzbekistan used to be the 4th largest lake in the world until the rivers feeding it were diverted by the Soviet Union to irrigate farmland. By 1997, it was less than 10% of its former size and heavily polluted.
High water use is also required to process cotton into usable fiber and fabric. Creating a single T-shirt requires 700-1,700 gallons. Levi Strauss uses 3,781 gallons of water to manufacture a single pair of jeans and 10,000-20,000 gallons is used to produce the necessary cotton.
Cotton also relies heavily on problematic chemicals. Defoliants are used in mechanical harvesting and the chemicals remain in the cloth throughout the life of the garment. While more ecologically sustainable, hand-picking also has drawbacks: laborers, many of them children, endure horrendous working conditions for very little or no pay. Regardless of the harvesting method used, harsh bleach and chemical dyes, including Azo dye for denim, are often used in processing. Many are carcinogenic and all cotton releases micro-particles of fiber when washed which travel throughout water systems.
Finally, fads often increase the unsustainability of cotton. Finishes such as stonewashing and sandblasting make the garments feel softer, but the results are achieved through the use of chemicals or fine dust particles. With pre-shredded or distressed clothing, you pay more for garments whose useful life has been compromised.
Cotton: Organic & Recycled/Reclaimed
It’s possible to enjoy cotton fabric while maintaining your commitment to sustainability. Both organic and recycled/reclaimed cotton have a smaller environmental impact.
Organic cotton is grown and processed without using toxic pesticides or insecticides. Because organic farming utilizes crop rotation, the soil isn’t depleted, thereby eliminating the need for fertilizers. However, organic farming requires more land to grow the same quantity of fiber and is more labor intensive. Many organic farms rely on rain rather than irrigation, reducing water needs by 90%. By choosing to hand-pick the crop, not only do you get longer, softer fibers, but 60% less energy is used, and the plant itself is not harmed.
Purchasing a garment that has the Global Organic Textile Standard (GOTS) label ensures that strict adherence to environmental and ethical criteria have been maintained. The organization traces the garment from farm to store. Some manufacturers will put an “organic” or “natural” label on their clothing, but that doesn’t mean that it has been sustainably made. The GOTS label ensures that there is substance to back up this claim.
Recycled fabric comes from pre-owned garments. Reclaimed fabric uses scraps and end-of-bolt pieces from manufacturers. The fabric may still be unsustainably grown and manufactured, but if not re-used, it would just add to our landfills. Recycling only uses 20% of the water needed to originally manufacture cloth. Unfortunately, it isn’t easy to recycle cotton. It must be sorted by dye color then rewoven. Also, the end product doesn’t have the same quality as the original because the fibers are shorter and rougher.
Polyester: Unsustainable, Yet Recyclable
Polyester (including nylon and acrylic) is used in up to 65% of all clothing manufactured. It’s created from petroleum and has the same disadvantages as plastic, yet is popular because it is versatile, inexpensive, and can create stretchy and wrinkle-free garments.
Creating polyester is extremely energy intensive. To meet current needs, 70 billion barrels of oil are used every year. Manufacturing requires large quantities of water, fossil fuels, and various other types of chemicals. It produces toxic and carcinogenic chemicals including nitrous oxide and antimony which are dangerous to the heart, lungs, liver, and skin. Not only is polyester not biodegradable, every time a garment is washed 700,000 microscopic beads of plastic are released to work their way through our water systems. These microplastics end up in the oceans and our food supplies.
Even though polyester is not biodegradable, it’s infinitely recyclable. In fact, the fabric improves with recycling – it becomes softer and lighter feeling with no loss of durability or strength. Recycling keeps it out of our landfills, requires half the energy, and releases only 25% of the harmful emissions that creating new polyester does.
To recycle polyester, old fabric or plastic (from water bottles or food/household containers) is broken down to small chips which are heated, then pressed through a spinneret, to form long strands that can be spun into yarn. While little water is used, this process still requires a great deal of energy.
Recycled polyester (also called rPET) is far more sustainable to manufacture than virgin polyester and doesn’t deplete a non-renewable resource (oil), but it’s still not biodegradable and continues to release microplastics with each washing. Recycled polyester is becoming more common and, by 2030, 20% of all polyester will be recycled.
Cotton and polyester are the two most popular, and least sustainable, fabrics used for clothing. It is also very common to combine the two to create a blend. Poly/cotton highlights the best qualities of each: polyester is stretchy yet sturdy, wrinkle- and shrink-resistant, and cotton adds softness and breathability. Including polyester also reduces the price of the garment. Unfortunately, blending the two yarns makes it impossible to recycle because the fibers can’t be separated. While each is individually recyclable, together, the only option is the landfill.
Wood-Based Fibers: Viscose, Nylon, Modal
The third most common fabric is actually a group of fabrics that can’t be characterized as natural or synthetic. Viscose and modal use the pulp of trees (birch, beech, oak, eucalyptus, or bamboo) and put it through enough chemical processing that it doesn’t qualify as a natural fiber like cotton, hemp, or linen. The sustainability of wood-based fiber varies based on growing, harvesting, and processing practices.
Growing & Harvesting: When fast-growing, renewable trees, like bamboo, are used, viscose is more sustainable. Unfortunately, many times mature trees are used, or old-growth forests cleared to make room for new planting. 30% of viscose is made from endangered or ancient forest pulp. Poor forestry practices can also lead to soil erosion.
Processing: Once the wood is cut, the pulp must be softened using a chemical soup. Many times non-toxic chemicals are used in a closed-loop process. This means that the same soup is continually reused and isn’t discarded into the environment, making the fabric more sustainable. Some processors choose more harmful chemicals such as caustic soda, sulphuric acid, or carbon disulphide and release the waste into the air and water systems. These chemicals have been linked to heart disease, birth defects, cancer, and skin conditions in factory workers and those living in the immediate area. Once the pulp is softened, it’s filtered, spun into thread, and then fabric. Regardless of soup composition and disposal, the entire process is fairly water and energy intensive.
Sustainable Options: Bamboo is one of the fastest growing plants in the world and thrives with little water, fertilizers, or pesticides. It doesn’t have to be replanted after harvesting because the root system will send up new shoots. While bamboo fabrics are becoming more popular (good for sustainability), it is still more expensive than its polyester or cotton counterparts and needs chemical processing to create the fabric. Its advantages include durability, silky feel, wrinkle-resistance, being safe for sensitive skin, recyclable, and bio-degradable.
The eucalyptus used to make Tencel/Lyocell™ is grown on sustainable plantations, processed using a closed-loop system, and even the waste water is recycled. Not only is it certified biodegradable, it is moisture-wicking, naturally wrinkle-resistant, soft, and 50% more absorbent than cotton. It is considered one of the best choices for sustainable fabrics.
Potentially Sustainable Fabric From Animals
Animal Fibers: Sheep, Goat & Alpaca
There are a variety of wool sources to choose from; some are extremely sustainable while others are detrimental to the environment and more harmful to the animal. Generally, wool is more sustainable than cotton or polyester because lower quantities of water, other chemicals, and energy are needed. These needs vary depending on the source of fiber.
The most sustainable wool comes from Alpacas. These relatives of the llama family live in the Andes Mountains of South America on marginal land that is not otherwise arable. (They are also now raised in the United States, Australia, and New Zealand.) They require very little water or food to survive. In fact, they eat only 1-2% of their body weight daily and, when they graze, they snip only the tops of the plants rather than pulling greens up by the roots. Alpacas also have very soft feet, so unlike goats and sheep, they don’t disturb the soil. Alpaca fleece is naturally shed in spring as a single mat, or can be sheared without hurting the animal. Each alpaca provides enough wool for 4-5 sweaters per year.
Processing alpaca fleece into usable fiber requires no toxic agents, and very little water or energy. Because it doesn’t have a greasy lanolin coating like sheep wool, it doesn’t need to be scrubbed with harsh soaps. The lack of lanolin also makes alpaca hypoallergenic and it doesn’t hold dust so the garment won’t have to be washed as frequently. The finished garment is soft, and among the lightest, strongest, and most sustainable natural fibers known.
Camel hair sustainability is very similar to alpaca’s. Most camels live in the Mongolian Steppes, although they can also be found in Turkey, China, Siberia, Australia, and New Zealand. They also shed their coat naturally, have very soft feet, need little water, and live in remote areas that aren’t conducive to agriculture. Traditional methods of collecting, processing, and spinning are used that rely on tools that don’t require energy.
Sheep (Merino) Wool
The majority of the wool used in fashion comes from sheep. Its unsustainability is due to the number of animals needed (1 billion sheep are raised worldwide to supply this need), and the effect of overpopulation on the environment. The two primary areas of unsustainability are:
- Sheep emit a lot of methane gas which is 25 times worse for global warming than CO2.
- They are responsible for over-grazing in many areas such as Patagonia where 30% of the region has been affected by desertification and soil erosion.
Processing wool requires minimal water and energy use. The greatest use of bleach, water, and other chemicals is during the dying stage. Even though heavy metal dye fixatives are used, excess dyes pollute water systems. There are also chemicals used on the sheep for insecticide baths that will remain in the wool throughout processing,and are of serious concern to human health, the health of other livestock, and the health of the local ecology.
Sheep can be raised sustainably. They can live in areas with only marginal ecosystems and when managed well, do not harm the environment. Wool is a renewable resource that is also bio-degradable and retains most of its quality when recycled. Recycling not only reduces the burden of raising sheep, but 11 Kilograms of CO2 and 500 liters of water are saved per kilo of recycled wool produced.
One of the greatest concerns with wool harvesting is a practice called “muling” during which part of the skin is removed along with the wool. While it helps prevent infections, it makes the shearing process even more painful for the animal. New Zealand is known for having strict regulations about all facets of the wool industry and produces some of the finest fabrics available.
Goat Wool (Cashmere)
Cashmere is known for being luxurious. Unfortunately, it is the least sustainable of all wools; its popularity is responsible for great harm to the land. Cashmere is created from Zalaa Ginst, Capra Hircus, or Pashmina goats that live in the Tibetan plateau, Outer Mongolia, and China. While the land could reasonably sustain the 5 million goats that occupied it in 1990, demand led to a population explosion. In 2009 there were 20 million goats in Mongolia and 123 million in China. So many goats are needed because each goat produces so little fiber. It takes the output of 4 goats to create 1 sweater (as opposed to 4-5 sweaters per alpaca).
The increased demand has led to over-population and over-grazing of significant portions of Mongolia to the point that desertification now threatens 90% of the country. Goats rip out the roots of plants and their hooves are very sharp so soil erosion is a serious concern. Aside from the damage caused by the animals, producing fabric from fiber is not especially unsustainable. Processing the fleece has similar impacts to processing wool.
While leather isn’t a woven fabric, it is still part of the fashion industry – and one of the least sustainable and most wasteful materials through all phases of production. There are 1 billion cows killed every year to meet leather needs and each cow emits 70-120 kilograms of methane per year for a total of at least 154 billion pounds or 14.5% of all methane emissions.
Leather production is extremely wasteful because manufacturers have to work around the inherent shape of the hide. Depending on the end product, 30-85% of the hide is waste. Aside from raising the cattle, the tanning stage is very unsustainable. Although it is possible to use non-toxic chemicals and natural vegetable dyes, 85% of leather is tanned using chromium – a carcinogenic and toxic irritant to sinuses and lungs. Most tanning occurs in countries with few safety or environmental regulations and workplace injuries are common. Workers are not the only ones affected by the toxicity; 16 million people are at risk from chromium exposure by the 22,000 liters of waste water dumped daily into rivers by tanneries in Bangladesh.
People who object to wearing leather for ethical reasons of animal cruelty have the option of purchasing faux leather. Unfortunately, this is made of PVC plastic or polyurethane and is very bad for the environment (see polyester). Luckily, people are experimenting with sustainable innovations. Piñatex™ simulates leather without toxicity or waste. Bolts of material are fabricated using the waste leaves of pineapple plants that are removed to make room for new growth. This utilizes part of the 40,000 tons of leaf waste that would otherwise be burned or left to rot. The process up-cycles agricultural by-products and provides a secondary source of income for farmers.
Piñatex avoids using use toxic chemicals to produce a sustainable fabric that can be dyed and printed and comes in a variety of thicknesses. Not only does the uniform shape reduce waste while cutting pattern pieces, but no additional water, fertilizer, pesticide or land use is needed to produce a durable product that costs 40% less than leather.
Another textile innovation that mimics leather is MycoWorks™. It is made from mycelium or mushroom skin. It has a small environmental imprint to produce, and is biodegradable. The roots of the fungi mycelium create a mesh of nutrients that coalesce within a few days to make a luxurious and sustainable fabric. During the incubation period it can adhere to accessories like buttons and zippers so stitching and fusing are unnecessary.
The sustainability of silk is part good, part bad news. Silkworms are a renewable resource and they feed on mulberry trees which are resistant to pollution and easy to grow. Silk is biodegradable. However, silk dying requires heavy chemical use and a lot of heat. Huge quantities of silkworms are needed to make a single garment (5,000 for a kimono). The greatest objection to silk is that the worms are boiled alive before the cocoons can be processed. One company, Ahimsa, waits until the worms shed the cocoon naturally before processing. The final product is coarser, but has the same gloss as traditionally spun silk. The primary difference is the ethical treatment of the silkworm.
Fabric Sustainability At-A-Glance
There are several sustainable innovations in development that simulate silk.
- Qmonos™ is a synthetic spider silk. Spider silk genes are combined with microbes to create the toughest fiber in nature – 5 times stronger than steel. It is also lightweight, more flexible than nylon, and biodegradable. The spiders are not farmed or harmed in the process.
- Microsilk™ is also a lab made spider silk. It combines water, yeast, sugar, and a pinch of DNA. Bioengineered genes are implanted into the yeast and fermented. The silk proteins produced are extracted and spun into yarn. Microsilk holds dye 6 times better than silk.
- Citrus fiber is being spun into material resembling silk. The cellulose fiber is a by-product of the 700,000 tons of citrus “pastazzo” paste that’s produced in Italy. While a small proportion of this waste is used for animal feed and fertilizer, most would go straight to a landfill, or be illegally dumped, where it would increase global CO2 emissions. This is another instance of an agricultural waste product being repurposed to create a new fabric.
- Cupro™ uses the discarded fibers from the outer shell of cotton plants. The result is a fabric that has the flow and sheen of silk, is biodegradable, recyclable, anti-static, breathable, accepts dye well, and resists shrinking.
- Seacell™ is a soft, silky, absorbent fabric that is made from algae. It’s created using a closed-loop process so zero chemicals are released. Seacell actually has health benefits for the wearer – the algae’s beneficial mineral and vitamin properties are absorbed into skin. The fabric also protects against harmful UV rays.
Other plant by-products that are being transformed into sustainable fabric alternatives include:
- Tasc™ is a blended fabric of organic bamboo, organic cotton, wool, and spandex. The combination creates a high-performing fabric that is soft, repels odors, has UV protection over 50, and regulates body temperature. The only unsustainable portion is the bit of spandex used to provide elasticity.
- Cocona™ is made from activated waste from coconut shells and volcanic sand that comes from water filtration systems. They are mixed with a polymer base and bonded to an existing fabric. It has a low carbon footprint, keeps waste materials out of the ecosystem, and enhances the fabric it is attached to.
- Banana fabric uses the leaves and stems of banana plants after the fruit is harvested. A sustainable chemical solution softens the fibers but the processing is almost carbon neutral. The fabric is durable, water-, fire-, and tear-resistant, biodegradable, and recyclable.
- Using the same production processes as Tencel, Refibra™ combines cotton scraps with wood fibers so it is environmentally responsible.
- Econyl™ recycles fish nets, plastic and reclaimed fabric to create a nylon-like yarn. It is as durable as virgin nylon with the bonus of removing dangerous plastics from the ocean and fabric waste from landfills and re-purposing them.
Final Thoughts on Sustainable Fabric
Fast Fashion = Unsustainability
Choosing sustainable fabrics is only half the challenge. Our shopping habits and the industry’s reliance on fast fashion are equally responsible. People are buying a greater number of items for less money than ever before. The average US household spent the equivalent of $4,000 for 25 garments 50 years ago. In 2020 that figure is $1,800 spent on 70 garments. Worldwide, more than 80 billion pieces of clothing are consumed every year. The fashion industry prospers by promoting new fad garments every couple of weeks to encourage continual purchasing. This emphasizes quantity over quality and leads to more clothing ending up in landfills.
People can combat this trend by choosing to buy fewer garments made with recyclable or biodegradable fabrics that are sustainably and ethically produced. The industry is starting to champion innovative fabrics produced from waste sources. This gives the consumer more, and better, choices. Fortunately, many of these fabrics offer unique and beneficial qualities: moisture-wicking, UV protection, anti-bacterial, anti-microbial, and odor-resistance.
If you are committed to purchasing the most sustainable fabrics available, the Higgs Sustainability Index gives an in-depth analysis of many choices. Consider what types of resources are needed to create the fiber: land requirements and desertification, water, energy, and chemical use, greenhouse gas emissions, and whether a garment is renewable, recyclable, or biodegradable. The primary goals are to keep harmful chemicals out of the environment and waste out of our landfills.