Guide to natural fabrics

Textile materials are mass-consumption products, largely due to the rise of so-called “fast fashion” in recent years, which has led to an unprecedented environmental impact that already accounts for 10% of global carbon emissions.

According to the European Environment Agency, in 2020, textile consumption per average EU resident required 400 m² of land, 9 m³ of water, and 391 kg of raw materials, and all of this caused a carbon footprint of 270 kg of CO₂ per person. [1]

For this reason, the textile industry has become one of the most controversial sectors, both in the definition of international trade agreements and due to its longstanding failure to comply with minimum labour and wage conditions and its constant offshoring.

Cotton and polyester together account for more than 80% of the textile fibres consumed annually worldwide, and both fabrics depend on petrochemical processes: in the case of conventional cotton, due to the pesticides and herbicides used for its cultivation, and in the case of polyester because it is a fibre obtained directly from petroleum. [2]

For all these reasons, choosing natural fabrics whose production processes follow the principles of sustainability is an essential practice for developing a real alternative to this global problem, which must go hand in hand with reduced consumption and the recycling of discarded textiles.

But beyond the clothes we wear, textiles are widely used in architecture and interior design: we find them in rugs, carpets, furniture upholstery, curtains, bedding, towels, etc.

In this regard, and with the aim of reducing the ecological footprint of the spaces we inhabit in line with the goals set out under the Paris Agreement, the use of natural, toxin-free, locally sourced fabrics is an essential requirement to decarbonise built spaces and the elements that make them up.

Where do the fabrics we use come from? How can we replace plastic fabrics with highly durable natural fabrics? How can we produce in closed loops that recover and add value to textile materials at the end of their service life? Which natural fabrics are most suitable for our spaces?

These are the questions we aim to answer in this article, in which we explore manufacturing processes, circularity, and the most relevant certifications, among other aspects such as the most suitable applications for each natural fabric.

Types of natural fabrics

Organic cotton, hemp, bamboo, soy, corn, seashells, algae… today, virtually any material can be used to make fabrics, but not all fabrics labelled as eco-friendly have the same properties.

The fact that they are fibres of natural origin does not mean that the processes used to obtain them cannot cause serious environmental damage.

An example is the production of non-organic cotton fabrics, which today is the crop that uses the most pesticides in the world, contributing to water pollution and biodiversity loss. That is why in this article we will refer only to its organic variety as an example of a natural fabric.

On the other hand, many plant fibres presented as alternatives, such as hemp or bamboo, can have a high ecological footprint because, due to their hard and resistant nature, they must undergo intensive treatments to become textile fibres. These processes are not always carried out organically; harmful chemicals are often used to speed up the process and reduce costs. This is without even considering the dyes and finishes that may be added afterwards, for which there are very few eco-friendly alternatives.

As always, it is important to assess the full life cycle of each production process, market placement, and end of service life, taking into account the ecological and carbon impact, but also the effects of the toxins used on people’s health and the environment.

Cotton

According to the latest studies by the OTA, the Organic Trade Association, non-organic cotton accounts for 2.4% of the world’s arable land, using approximately 25% of the pesticides used worldwide (including herbicides, insecticides, and defoliants). [3]

As we know, the health of the planet and people are closely linked, and this is precisely what Stephen Yafa, author of Big Cotton, denounces when he states that 91% of people working in cotton fields in India often fall ill due to exposure to these toxins. [4]

Given these figures, it is not difficult to imagine the high likelihood of illnesses developing as a result of the end consumer’s exposure to these toxins, in a society that spends increasing amounts of time indoors. In fact, major retail chains have already begun offering organic cotton garments—whose production process may be more than questionable—recommending them for people with sensitive skin.

Organic cotton comes from controlled, environmentally respectful crops that do not use pesticides or chemical additives in fertilisers. However, organic cotton is not a perfect solution, as it requires large amounts of water both for cultivation and washing, and in many cases it is transported across several continents to its final destination. [5]

Although cotton is widely used in clothing, it is also used in the home for bedding such as sheets and pillowcases, duvets, and mattresses. It can also be found in roller blinds and cotton curtains, as well as in towels, due to its high absorbency.

In construction, cotton is also widely used as thermal and acoustic insulation in the form of pressed panels made from shredded clothing waste.

Wool

Sheep’s wool is one of the few natural textile fibres of animal origin, which gives it a high hygroscopic capacity that can buffer changes in ambient humidity, which is why it is widely used as insulation. In addition, this ability to absorb moisture, combined with the protein components of the fibre, makes it an inherently flame-retardant natural fabric. It is also highly resistant to dirt, as the fibre structure gives it the ability to repel liquids and keeps dirt and dust near the surface, making it easier to clean by vacuuming.

Sheep are often confined to pastures that are too small, which causes overgrazing and damages the land. Pesticides are also used both on the pastures and on the animals themselves to control pests and parasites.

According to a study by the Organic Trade Association (OTA), the pesticides most commonly used in sheep farming—fenvalerate, permethrin, and malathion—are highly toxic to fish and amphibians. In addition, the widespread use of agricultural antibiotics is contaminating surface and groundwater in many rural areas, as a result of the manure produced by the animals. [6]

As a response to this issue, and similarly to organic cotton, organic wool is presented as a solution, limiting the amount of antibiotics used on sheep and the number of sheep per hectare.

However, as with cotton, chemicals are used in cleaning, bleaching, dyeing, and finishing wool-based fabrics. Therefore, for wool to be considered free of chemical agents, it must not only be produced organically, but also processed organically.

Hemp

Hemp has been used for millennia as a source of fibres and, more recently, as the fabric used in the first pair of Levi’s jeans, which gave rise to a global market based on this clothing, designed to last under extreme working conditions.

Due to its rapid growth—it reaches maturity in 80 to 120 days—and low irrigation needs, it is one of the fibers with the lowest ecological footprint. [7]

Hemp is four times stronger than cotton, and also more resistant to abrasion and mould. In addition, it requires far fewer pesticides or other chemicals, proportionally speaking.

Despite all the advantages mentioned, hemp, like flax and jute, is a coarse fibre, so it requires an additional fibre-extraction process called retting. Although it can be carried out organically using microorganisms, it is increasingly done using chemical derivatives, softening the fibre with caustic soda and acid washes.

This process causes the resulting fibre to lose most of its qualities, such as durability, and it also produces hazardous waste that is destructive to the environment. [8] However, it is not as harmful as the process used for bamboo or wood to extract their derived natural fabrics, as the plant breaks down more easily.

Bamboo and soy

Bamboo and soy are similar in that they are two types of crops that renew easily. However, their high consumption has recently led, in some cases, to the absurd practice of cutting down forests to plant them as monocultures—a situation that cannot be classified as sustainable farming, as it prevents any kind of biodiversity.

If grown sustainably, bamboo naturally resists pests, so pesticides are not necessary in its production, although they are often used in monocultures. In addition, it requires a great deal of work to be transformed into fabric, as it is a very rigid grass.

There are two ways to process bamboo: mechanically or chemically. The mechanical method involves crushing the plant and using natural enzymes to break it down so that the resulting fibres can be spun, producing what is known as bamboo linen, as it is a process similar to flax. This process is largely done by hand, which makes the product more expensive, and consequently very few manufacturers use it. [10]

The most widespread alternative is a highly polluting chemical process based on solvents such as caustic soda and bleach, which create sulphide emissions that act as neurotoxins.

This is a process very similar to soy fabric or viscose, in which the raw material is renewable but the process and high amount of toxins make it impossible to classify it as a natural or sustainable fabric. [11]

Coconut fibre

Coconut fibre is the natural fibre extracted from the coconut husk, uncommon in the textile sector. The so-called fragments, strands, or hair of the fibre are typically 10 to 30 centimetres long and can be braided for use in products such as rugs, doormats, curtains, awnings, ropes, and insulation. Coconut fibre contains more lignin and less cellulose than fibres such as flax and cotton, making it stronger and less flexible.

Cellulose

The most widespread cellulose fabric globally is viscose, widely produced in Asia and a source of pollution on the continent. Paradoxically, its origin is not inherently unsustainable, since as a plant-based fibre it can be obtained from the cellulose of a wide variety of trees and plants, and it can also be biodegradable at the end of its life cycle.

For this very reason, there are brands that market it as an eco-friendly fibre, even though its production uses large amounts of toxic chemicals to turn this raw material into fibre.

In addition, like all wood derivatives, if sustainable sourcing management is not guaranteed, it can threaten forests by causing deforestation. [12]

For this reason, natural cellulose-derived fabrics have recently been developed with closed-loop processing systems that limit emissions. Known as Lyocell—Tencel is its patented trade name—it is a regenerated and treated cellulose fibre whose manufacture minimises its environmental impact. [13]

The cellulose source is wood pulp, in this case from sustainable FSC-certified forests, which is broken down using a non-toxic solvent that is also continuously recycled, with a 99.5% recovery rate. In this case, its producers can state that the final product is fully biodegradable.

Jute, Sisal, Esparto

Jute is a tropical herbaceous plant that grows to 3–4 m tall and 2 cm in diameter, from whose main stem jute fiber is extracted. It is mostly grown in India and Bangladesh, so it is difficult to find domestically produced jute.

This natural fiber is well known because it is widely used to make sackcloth, an example of natural jute fabric without any treatment. In fact, its production process is entirely artisanal: the plants are cut, tied into bundles, and dried; then the bundles are retted and the fibers are separated at 30°C. Its rustic look makes it an ideal natural fabric for curtains and upholstery. [14]

Sisal is extracted from the succulent plant native to Mexico called Agave Sisalana, a different variety from the one used to produce the well-known mezcal.

Today, it is grown in tropical areas in Brazil, Tanzania, Uganda, and Kenya. Production uses the pointed leaves, known as pencas, which undergo a scraping process that cuts and separates the fibers lengthwise, and are then dried.

The resulting natural fabric is very similar to jute and is also used for sackcloth and ropes. It is characterized by a certain stiffness, which makes it ideal for incorporating into the home. [15]

Esparto grass is the local alternative to the fibers mentioned above. These fibers are obtained from various wild plants in the grass family, a traditional practice carried out in arid areas of the Iberian Peninsula (Andalusia, Aragon, the Valencian Community, La Mancha, Catalonia, the Balearic Islands, and Murcia) and in the Maghreb region of North Africa.

Its natural regrowth is as simple as the wind carrying its own seed, making it the most primitive and economical cultivation system, requiring virtually no care beyond clearing the scrubland in June to harvest the plants.

The production process is very straightforward because the fiber is almost exposed: it is first soaked in water ponds to soften it, then crushed to remove the woodier part, and finally combed before spinning. Esparto grass has been used since time immemorial to make all kinds of objects, from ropes, shoes, and baskets to scouring pads. [16]

Flax

Linen is one of the oldest textile fibers, a plant-based fiber characterized by good air permeability, which is why its popular use is associated with lightweight summer clothing.

It is a fast-growing plant that can be cultivated without pesticides or fertilizers and uses very little water, so it can be considered highly sustainable. In addition, the fiber is 100% circular because the by-products of its production process are used as secondary raw material.

The result is a biodegradable natural fabric whose production energy use is 4% to 10% of what would be needed to produce synthetic fibers. [17]

Its use as natural insulation is not widespread in Spain or the rest of Europe, with Russia being its main exporter. However, in Europe, France, Belgium, the Netherlands, and Italy are experts in these crops, and today European linen is considered higher quality than that from countries such as Canada or China.

Algae

Recently, algae-based textiles have begun to be studied, with their proponents proposing them as the future of the fashion industry. It is a carbon-negative product free from harmful chemicals and fertilizers, which makes it good for the planet and its consumers. But the most innovative aspect of this product is the colors it can achieve in a completely natural way, taking advantage of the inherent tones of algae. [18]

Recycled

In recent years, a large number of synthetic materials are being proposed from recycled sources, giving a second life to non-biodegradable materials so they follow a circular life and do not become waste.

However, it will not only be necessary to analyze the emissions derived from these transformation processes and the percentages of recycled material, since in some cases a minimum of virgin raw material is required, but also the toxins present in these raw materials migrate to the final product, potentially being harmful to the health of users and the planet.

The most widespread case is synthetic fabrics based on recycled polyester, whether obtained from PET plastic bottles or from already used garments.

Furthermore, regarding polyester, it is necessary to keep in mind that when garments made of this material are washed in the washing machine, very small plastic threads called microfibers are released, which cannot be trapped by normal filters and end up reaching the sea, causing a serious ecological problem.

Another cause for concern is the legal vacuum that these materials face at the level of policy frameworks for regulating substances in the European Union.

Reused or recycled materials are subject to lower standards or exemptions for toxic substances. This means they are not subject to the same health standards as new materials, which are admittedly easier to control if we carry out the production process from start to finish. However, it is also possible to measure and control the concentrations of substances in fabrics of recycled origin, both in the recycled raw material and in the final product.

An example of this inequality is the flame retardant pentaBDE (Pentabromodiphenyl ether), which is regulated under the Persistent Organic Pollutants regulation, which has a concentration limit of 0.001% w/w for virgin material but 0.1% w/w in recycled material. [19]