Biodegradable clothing: facts and myths

As fast fashion speeds up its production rate each year, with some online retailers launching a few thousand new styles per month, sustainability efforts of smaller fashion brands may seem to have little impact. Each year around 40 million tonnes of textile waste ends up on landfills or is incinerated. Wouldn’t it be amazing if instead it could just decompose and go back to nature?

Could biodegradable clothing be the solution, which makes fashion industry more environmentally friendly?

What is biodegradable clothing?

The difference between the terms “degradable” and “biodegradable” is not always clear to consumers. However, the it is quite significant, as biodegradability is a specific type of degradability.

All textiles, as well as all other products, are degradable, as they can be broken down biologically or chemically.

Biodegradability is a different story. Biodegradable clothes have to be made from materials, that can decompose naturally, as a result of action of biological agents. These agents could be animate, such as plants, animals or bacteria, but also inanimate, such as rain, soil and sun. Biodegradable clothing fits into the circular economy model, while it isn’t always so for degradable garments.

Here are some facts and myths about biodegradable clothing, which can cause some confusion during discussions about sustainable clothing.

#1 If the fabric is biodegradable, the garment is 100% compostable.

This is definitely a myth.

A piece of clothing is not only the fabric, but also seams and ornaments, which can transform a few meters of cloth into a piece of art.

However, this means that when we are assessing the biodegradability of an item, sewing threads, zippers, buttons or additional ornaments such as sequins or studs have to be taken into consideration. The claim on biodegradability of the fabric doesn’t address those elements.

Let’s imagine a pair of linen shorts with a zipper and some buttons. First of all, the sewing thread would usually be manufactured from polyester or cotton wrapped around polyester, therefore it would break down in 200 years, not in 2 weeks as the linen. Moreover, the end result will be microplastic, which is an environmental problem. The same fate awaits the buttons and zippers, as they are also usually made from plastic.

Another issue regarding the biodegradability regards dyes and finishes used in the production. Petroleum-derived synthetic dyes and chemical treatments that ensure wrinkle or stain resistance will leak into environment and pollute it as the fabric decomposes.

#2 Natural materials biodegrade cleanly and quickly

It sounds reasonable, as they are plant or animal originated. However, it is not always the case and therefore it is a myth.

First of all, the issue of dyes and finishes enters into the picture again. The way we treat the fabric after it has been spun and weaved is crucial for its entire life cycle, including the decomposition. Biodegradable dye have to be free from heavy metals and other toxic substances that could cause environmental problems. Natural dyes can be a great solution to assure biodegradability of a garment. They can be produced from plant, fruits, starfish, algae or even bacteria.

It is true that natural materials, such as cotton, silk, wool, linen, alpaca and hemp, are biodegradable. However, our clothing is often made from material blends, which include more than one fabric. If the garment is made from a material blend of natural and synthetic fibres, for example its composition is 50% cotton and 50% polyester, the natural fibre will not biodegrade. Moreover, with the current state of technology, we cannot recycle such a fabric. The same goes for cellulose and natural material blends.

Why do brands use such materials then? Opting for a material blend can enhance the appearance of the garment and its durability, therefore making it more sustainable.

Having said all that, it is true that 100% natural materials dyed and finished with environmentally friendly  chemicals are biodegradable:

-        Cotton will biodegrade in 5 months (or in 10-12 months in the case of denim).

-        Hemp and linen will biodegrade the fastest, in just 2 weeks.

-        Silk will decompose 1-4 years.

-        Wool takes less time to decompose than cotton, it will break down in 3-4 months.

Keep in mind that the time of decomposition depends on soil, climate and other natural agents, therefore burying the garment in your backyard might not a be a great idea. When the garment has reached its end of life, you should dispose of it in a way that allows for it to be shipped to an industrial decomposition plant.

#3 A compostable garment will decompose in your backyard

Finally, the type of garment you can just put in you compost heap! Yes, this is a fact.

What are the prerequisites for a material to be compostable?

First of all, the material needs to be biodegradable, which means made from natural fibres or biodegradable synthetic fibres. Secondly, the chemical treatments such as dyes and finishes should be kept to minimum, not toxic for the environment and decomposable in the conditions of the compost heap. Last, but not least, buttons, zippers, sewing threads and other element should also be compostable.

This is a lot of conditions to be met. Too be on the safe side, it is always better to double check the item and in case of doubts, leave the biodegradation process to a specialized plant.

4# Polyester is biodegradable

This is a myth, and a harmful one at that.

Most of the plastic currently in use is not biodegradable. This also applies to polyester (PET) fibres in our clothes. Its decomposition time takes from 20 to even 200 years. And after it decomposes it becomes microplastic.

You have probably already heard about the issues related to microplastic, especially its adverse effect on marine life and human health. If not, here are some statistics to illustrate how big the issue is.

At least 14 million tonnes of plastic end up in the oceans each year, and currently we have around 5.25 trillion macro and micro pieces of plastic floating in the oceans. According to estimates 1/3 of the microplastic present in the oceans can be attributed to the textile and fashion industry. No wonder, seeing that the 57 million tonnes of polyester fibres were produced just in 2020.

And how does bioplastic compare to traditional, fossil fuel based plastic?

Bioplastic derives from biomass, for example sugarcane or potatoes. Their manufacturing process as a lower carbon emission and pollutes the environment less in general. Not all of the bioplastics are biodegradable, however the ones that are, for example polylactic acid, will degrade into CO2 and water.

As no material is perfect in regards to sustainability, also bioplastics have their drawbacks – the land and water use for production of biomass is significant, and can have adverse impact on cultivation of crops that are food sources for local populations. Moreover, as biodegradable bioplastic can be difficult to set apart from fossil-fuel based plastic, many biodegradation plants are hesitant to accept it for processing.

Is biodegradability the future of fashion?

It seems like for now the challenges in producing truly compostable garments, as well as the small availability of biodegradation plants limit the positive influence biodegradable clothing can have on the fashion industry. This area of sustainability is still in its infancy, however, with time, it can make a big difference for fashion’s impact on the environment.

For now, when choosing a fabric one should ask themselves one question – is it more important for this product to last many years or be biodegradable?

In a perfect world, we would choose both, but in reality in many cases these two properties can work against each other. Therefore, for a classic outwear piece which is supposed to last many seasons it is better to prioritize durability, while for trend based items with shorter life span biodegradability or recyclability is the key.