Understanding what your clothes are *actually* made of

When was the last time you stopped to check what your new purchase was made from? And more to the point, if you knew it was made from a cheap and harmful synthetic material, would you still buy it anyway?

Before you reach the checkout, the item of clothing you’re buying is already destined for the landfill. This is because 80 percent of clothing produced ends up as waste, waste that can take up to 200+ years to decompose, emitting harmful methane gas in the process.

It’s no secret that the fashion industry is the second largest industrial polluter, second only to oil, yet we’re still not educated about how are clothes actually come to be before they reach our favourite stores.

Globally, we consume about 80 billion pieces of clothing every year, an increase of 400% in the last two decades, and just  1% of the clothes sent for recycling are actually renewed, reused, repaired, upgraded or refurbished. In 2017, the Ellen MacArthur Foundation calculated that £500 billion of value is lost every year due to clothing underutilisation and the lack of recycling.

The term ‘biodegradable’ refers to the ability of a substance to decompose naturally via living organisms. It’s estimated that only one percent of our clothes is ultimately recycled into new garments. If 2019 is the year that consumers get serious about sustainability, then it’s time to understand exactly what is a polymer and where does it come from? It’s worth noting that clothing labels don’t tell a garments full story like who made it, the conditions they work in, or how little they’re paid, so it’s still necessary to question brands.

Below is a useful index to help decipher whether if your new €25 dress is *actually* worth it.

Biodegradable materials


Biodegrade time: 5 months

Cotton is among the top choices for the environment because it’s both biodegradable and compostable. It can take one to five months to biodegrade and is biodegradable both anaerobically (without oxygen) and aerobically (with oxygen). Modern landfills are sealed and keep out water and oxygen, making them anaerobic. Cotton will degrade under these conditions but much more slowly than in aerobic conditions, or in a compost heap.

Where to shop: Cos, Uniqlo, & Other Stories


Biodegrade time: As little as two weeks (if organic)

Linen is a soft, luxurious and breathable fabric. Made from the fibres of the flax plant - which grows in cooler climates than cotton and is robust against insects and drought - it's laborious to manufacture and has been worn for millennia (linen is one of the world's oldest fabrics dating back to 4500 B.C.). Linen's USP is its ability to stay sweat-free, which is why it's so popular in warmer climates. When untreated (i.e. not dyed) it is fully biodegradable as fast as two weeks. It’s natural colours include ivory, ecru, tan and grey. White linen has to go through a heavy bleaching process. Sticking to its natural-toned hues will ensure a more environmentally friendly garment afterlife.
Where to shop: Reformation, Uterque, Kathryn Davey


Biodegrade time: 40 years

At the end of its life cycle wool products readily biodegrade, unlike most synthetic fibres. It takes about one year for natural wool to biodegrade, but can take as long as five depending on the blend.  The carbon-to-nitrogen-ratio of wool is quite narrow, meaning that wool has a high percentage of nitrogen. This high percentage of nitrogen is the reason wool biodegrades so well.

Where to shop: Lucy Nagle, Stable of Ireland, Fintan Mulholland 


Biodegrade time: 6-8 months or more

Silk is produced completely naturally from the fibres used by silk worms when they spin themselves cocoons to become moths, and so is very biodegradable. It takes about four years for silk fibres to begin to show signs of biodegradation. However, as silk becomes more widely available, more retailers are searching for alternative, cheaper and unethical methods of harvesting. In doing so, it raises questions about how ethical silk is.

Where to shop: KEEM, The Ethical Silk Company, Etro, Dries Van Noten, Balenciaga


Econyl is a specially-produced material made from regenerated nylon from landfills and oceans around the world. Created by Italian firm Aquafil, Econyl uses synthetic waste such as industrial plastic, waste fabric and fishing nets from oceans, recycles and regenerates them into a new nylon yarn that is exactly the same quality as virgin nylon.

Econyl has developed an eco-friendly nylon made from recycled plastics in a closed loop system, drastically reducing waste and emissions. Traditionally Nylon is not biodegradable, but Econyl helps reduce the amount of nylon in the deep sea.

Where to shop: Richard Malone, Stella McCartney, Mara Hoffman


Tencel is actually a brand name for a type of lyocell. Tencel is increasingly the fabric of choice for ethical and conscious clothing brands because of its lightweight and versatile nature. It’s a cellulose fibre, which is made by dissolving wood pulp and using a special drying process called spinning. Tencel has incredible absorption characteristics and is 50% more absorbent than cotton. Because they’re more breathable and less susceptible to odorous bacteria growth, these fabrics are perfect for a sweaty gym or Bikram yoga session, making them ideal for activewear. Ethical brand Reformation regularly use Tencel, citing it as "the holy grail of fabrics.

Where to shop: Mara Hoffman, Reformation, Christopher Raeburn

Synthetic Fabrics

Non-Biodegradable Clothes Take 20 to 200 Years to Biodegrade. Non-biodegradable clothes are manufactured synthetic textiles including polyester, spandex, nylon, and rayon. It may take between 20 to 200 years to fully biodegrade these textiles.


Found in: Activewear

Sometimes known as rayon, viscose is a soft semi-synthetic fibre commonly used to make lighter clothing, and is the third most-used fibre in the textiles industry after polyester and cotton. It is created from cellulose that is chemically extracted from trees, so in theory rayon is biodegradable but the process requires hazardous chemicals. The tree fibres are biodegradable, but the chemical extraction process is laborious and  pollution from production processes impacts surrounding water and soils. Rayon has significant potential to be a sustainable fibre, but dirty production must be stamped out now to make way for the introduction of more responsible methods.

Where to shop: Marks & Spencer, Topshop, Zara


Found in:  T-shirts, dresses, jeans, underwear

Polyester is another man-made fibre that replaced natural materials after the second world war. Today, polyester dominates the clothing industry because it’s inexpensive and widely available, with annual production exceeding 34 million tons worldwide.

Polyester is a polymer that is a plastic derived from crude oil that’s used to make soda and ketchup bottles. When melted, it has the consistency of cold honey, and if you squeeze it through a spinneret, kind of like the shower head in your bathroom, you get long, continuous filaments. Draw those filaments out into thin fibres, weave lots of those fibres together, and you have a fabric. Polyester can sit in a landfill for up to 200 years.


Found in: tights, stockings

Nylon was the first fabric made entirely in a laboratory. Its invention represents the dawn of the age of synthetics, and became widely available to the general public around the time of World War II. Essentially, nylon is a type of plastic derived from crude oil and is produced through an intensive chemical process. More specifically, nylons are a family of materials called polyamides, made from reacting carbon-based chemicals found in coal and petroleum in a high-pressure, heated environment. Nylon is strong, durable and has the ability to be moulded into shape, but the flip side to it is that it’s not biodegradable. This means when you’re finished with your torn tights, they sit in a landfill for 30 to 40 years. Producing nylon creates nitrous oxide, a greenhouse gas that is 300 times more potent than carbon dioxide.


Found in: Socks, hats, gloves, scarves, jumpers

Acrylic is lightweight, soft, and warm, with a wool-like feel. Some acrylic is used in clothing as a less expensive alternative to cashmere, due to the similar feeling of the materials. This, however, comes at a cost to the environment because acrylic is created from fossil fuels through a chemical process. It’s common that acrylic fibre and acrylic threads be woven with other types of fibre to create what’s called a ‘blend’. This is usually done as a cost cutting measure, since synthetic fibres are often cheaper than natural fibres. So if you see a shirt advertised as a ‘cotton-blend’ or ‘wool-blend’, it isn’t just cotton or wool, there’s another fibre in the mix.

Niamh O'Donoghue