How To Design Biodegradable Clothing

Designers looking to create garments that can safely return to the earth need to go far beyond simply using natural textiles.

Published 19th November 2020 by Nicole Obidowski

When you hear the term “circular economy” in fashion, your thoughts may go to cutting-edge textile recycling technologies that are being developed to turn post-consumer waste into new fabrics. While this is one way forward for circular fashion, we often forget that nature already offers a circular fashion solution – biodegradation.

Natural fabrics are made up of cellulosic fibres or animal proteins, which can be broken down and turned into compost by bacteria and fungi, under the same process as grass clippings and food waste. The resulting soil is full of nutrients, which can feed new crops. This is nature’s circular economy.

However, the way that the majority of garments are now produced and discarded means that the vast majority of clothing will never break down in this way. Most clothing is created using synthetic materials, and even if a garment is created using natural fibres, it may be loaded with so many toxic chemicals that bio-degradation would not even be desirable.

If you are a designer thinking about making your business more circular by incorporating biodegradable clothing into your collections, you will need to think further than simply using natural fabrics. This guide is designed to help you develop garments that can be successfully returned to the earth when their wearable life is through.

What exactly happens when clothing biodegrades?

Technically speaking, all materials are degradable, in that they will eventually break down, including synthetic fabrics such as polyester. However, how long they take to degrade and what conditions they require for degradation vary greatly.

The process of bio-degradation is primarily the work of bacterial micro-organisms that have evolved to digest organic materials. Man made petroleum products (including synthetic fabrics such as polyester, nylon and acrylic) are not something these organisms would naturally encounter, and as such they have evolved no means to digest them. Plastic will eventually be broken down instead by UV radiation from the sun, but this process is estimated to take hundreds or even thousands of years.

How long an item takes to biodegrade also varies widely according to the conditions it’s placed in. Aside from the presence of friendly bacteria, oxygen is another major factor in bio-degradation. Some materials require oxygen to break down, and for those that don’t, it takes a much longer time to degrade without oxygen. This raises problems as modern landfills are built to keep water and oxygen out, meaning if an otherwise biodegradable item ends up in landfill it may not be able to break down for a very long time, if ever, due to this lack of oxygen.

What fabrics are the most biodegradable?

There also is quite a wide variance regarding how long different types of fibres take to biodegrade, with some breaking down in as little as a couple of weeks while others may require several years.

It is difficult to accurately specify the degradation time of each fibre as it can vary by several months or years depending on the conditions it’s composted in. But generally speaking, plant-derived fibres, like linen or cotton, will break down faster than those derived from animal proteins such as wool or silk. Considering your kitchen compost would take 6 months or so to fully biodegrade, most of these textiles show similar or even better rates of degradation.

However, even among these groups there are large variations. For example, linen breaks down in as little as two weeks compared to cotton requiring up to 5 months. Wool can require up to a full year to break down, but silk has been recorded as taking as many as 4 years. So if bio-degradation is important to your brand values, it may be worth taking the time to consider how easily different fibres break down.

New types of biodegradable fibres are being developed all the time, and it’s worth keeping an eye out for developments such as Primaloft Bio, Pinatex , Mylo and Orange Fibre. These innovative new technologies tend to be difficult for small independent designers to access in early years, but hopefully over time more of these alternatives will become widely available so that designers can offer a wider range of biodegradable options.

How do chemicals affect the bio-degradation process?

Once the fibre has been harvested, that is just the first in a long list of processes required to create a textile product. Many of these processes are very chemical intensive and designers looking to make biodegradable clothing will need to think carefully about what toxins may have been applied to their fabrics, as they could be released back into the soil during composting.

Conventional cotton crops are highly pesticide dependent and it is believed that a certain amount of these chemicals may remain in the cotton textile. Rayon and viscose fabrics, including most bamboo, go through chemical processing to turn the original wood pulp into textile fibers, which in some cases may even prevent bio-degradation completely.

In what is termed “wet processing”, yarns and fabrics of any type are typically bathed in some combination of chemicals to help achieve the required texture, weight, hand feel, colour and performance of the final cloth. It has been estimated that finished fabrics contain as much as 27% of their weight in residual chemicals. Some of these chemicals have been proven to be highly toxic or carcinogenic, and if these components are leeched into the soil they may also find their way into water systems.

For brands seeking to achieve biodegradability with their garments, a Restricted Substances List (RSL) will be imperative. An RSL will detail chemicals that your brand does not allow in the processing of it’s garments and textiles. You can find an example list of the most toxic substances used in the fashion industry via Greenpeace’s Detox campaign, or for a more comprehensive list visit the ZDHC Roadmap to Zero website.

Once you have established an RSL, you will need to share it will all of your suppliers and ask for their support in confirming that none of the chemicals within it will be present in your supply chain.

You can also rely on stringent certifications such as GOTS or Cradle to Cradle to ensure the most harmful chemicals were not added to your garment or textiles in processing. This method may be a better guarantee, as it may be difficult for your suppliers to stay on top of each process that is being applied to every element of your garment.

You may also consider exploring natural dyes, which can create a wide and beautiful range of colours with no chemicals required. However, be aware that even naturally dyed fabrics may still be otherwise finished with dangerous chemicals. Furthermore, some natural dyes, such as indigo, can themselves be harmful to the environment in large quantities.

UPDATE 3/12/2020 : A recent study into human-generated oceanic microfiber pollution suggest that some plant-based textiles may not actually biodegrade as previously expected. While more research is needed, the most compelling initial theory would be that chemicals used in the synthetic dye process have significantly disrupted the natural bio-degradation process. Food for thought, and yet another good reason to explore natural dyeing.

What about trims?

When we are speaking of a garment, we are of course not just talking about a textile but also all of the trimmings that go into the creation of even very basic items of clothing. When the garment biodegrades, if these trims aren’t also biodegradable then they will be left polluting the environment.

Luckily, sustainable trims have come a long way in recent years, and items including the below list are readily available:

  • Organic cotton or linen tapes and cords
  • Organic cotton brand and care labels
  • Organic cotton thread
  • Organic shell and horn buttons
  • Vegetable starch buttons
  • Lyocell wadding
  • Biodegradable interfacing

Certain items you may not be able to find compostable versions of, such as snaps, rivets and zippers. You may try to design these items out, or they will have to be removed from the garment before composting.

Heat-dissolving thread, developed by Resortecs, has been designed to help easily disassemble garments for recycling – this technology could also help quickly remove any components that wouldn’t biodegrade.

It’s also important to remember that trims go through chemical processing as well, and highly-toxic AZO dyeing is often used on trims as it can efficiently be used to dye small amounts of material.

What about packaging?

It would seem a shame to take your biodegradable garment and pop it in a polybag inside a single use mailer, especially when there are so many different recyclable and biodegradable options on the packaging market.

Make sure you are considering all elements of your packaging, down to swing-tags, stickers, tape and tissue paper, as these can often be overlooked or assumed to be recyclable or biodegradable when they are not. If you take your time sourcing, you should be able to find biodegradable versions of all of these components fairly easily.

One thing you may find is that some products are listed as biodegradable, and others as compostable. It is worth remembering that compostable items will only decompose under certain ideal conditions, whereas biodegradable items will break down in most natural environments. So if your biodegradable polybag accidentally goes astray and ends up in the woods, it should decompose just the same as at an industrial composting facility.

Image: Vollebak

Putting it to the test

In order to find out if your garment is bona-fide biodegradable, you could of course shred a sample and pop it in your garden’s composting heap. However, this would take months if not years to yield results under sub-optimal conditions, and you wouldn’t be able to tell with any confidence if any harmful substances were being released.

Luckily, testing labs such as Bureau Veritas and Intertek can test your sample to find out not only how much time it would take to break down, but also what component parts it reduces to, so that you can ensure that you are fulfilling your promises and not accidentally participating in greenwashing, or poisoning your customer’s backyard veg patch.

It may be an extra expense to test your garments in this way, but I would highly advise it in order to ensure you are making responsible claims to your consumers.

How do I stop my biodegradable products from ending up in landfill?

The last thing you’ll want, after making all that effort to create a truly biodegradable garment, is for it to simply end up in a landfill, where a lack of oxygen could mean it takes decades to decompose, if at all.

Realistically, this will happen to some of the products you sell. Sometimes clothing will be binned whether you like it or not. But you will want to think about what actions you can take to encourage as many of your customers as possible to take the extra effort of composting their clothing.

Operating a take-back scheme may be your best bet, as you will then have control and responsibility for what happens to your product at the end of it’s usable life. Make sure you raise a lot of awareness around your take-back scheme by featuring it prominently on your website, posting about it on social media, and putting a note about it on the care label. You might even like to incentivize your customers to use it by offering vouchers in return for their discarded products.

Some of your customers may be interested in composting their own clothing once it is beyond repair. Textiles are not an unheard of component in composting blends, and wool fiber in particular is sometimes used as a garden mulch in it’s raw form. You could encourage this by posting home composting instructions on your website, detailing how to compost the items and how long they might take to break down.

Image: Fashion Journal

The linear economy, alongside other major factors (in particular intensive agriculture), is leading to huge topsoil loss, with nearly half of the world’s fertile soil disappearing over the past 150 years, and topsoil in the US now being lost at 10 times the rate it can be replenished. We need to protect and regain our fertile topsoil, as it is necessary for growing the vast majority of our food. Yet waste that should be converted back into soil is instead hermetically sealed away in landfill.

We often look for man-made fixes for man-made problems, but in the case of environmental destruction, nature often has it’s own solutions ready, if we take the time to understand and work within them. Fashion should take inspiration from efforts in other industries such as regenerative agriculture and rewilding, which are reconnecting us to ecological systems that the western world has ignored and disrupted for so many decades.

Designing a garment that can return to the same soil it was created from is certainly a challenge for modern designers, working within an industry geared towards a linear economy. But it also strikes me as a powerful and somewhat poetic reminder of fashion – and humanity’s – place on this earth and the systems that govern it.

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