Compostable textiles.
Degradability is a contentious subject, especially in textiles. There is a significant amount of greenwash coming from brands, I think, because there simply isn’t the understanding of what it means and what it looks like. The visuals are especially important. Some fashion brands are now claiming “biodegradable” on their labels, however this is being confused with “compostable”, even for garments that use synthetic dyes.
So what do these terms mean?
Degradable
Capable of being degraded - broken down - whether chemically or biologically. Most definitions of “degradable” consider this mostly in regards to chemical degradability, so decomposition from the action of chemicals. The item in question would then degrade [back] into its chemical composition i.e. as polymers (and monomers).
Biodegradable
Capable of being broken down by the action of living things i.e. microorganisms. The definition of “biodegradable” generally also states that the item degrades into innocuous products, meaning harmless or non-toxic.
Compostable
Synonymous with solid matter, rather than liquid, compostable refers to a product that can be placed into a composition of decaying biodegradable materials, and that which eventually turns into a nutrient-rich material. Compost is a mixture of ingredients used to fertilise and improve soil health, and is organic matter rich in plant nutrients and beneficial organisms. So for a product to be “compostable”, it requires the evidence that it will break down in a composting system and be beneficial. Liquids cannot necessarily be compostable, as compost comes into being through solid matter like vegetable scraps and plant waste.
Commercially compostable items - coffee cup lids, vegetable box coatings, cutlery - picked out of an aerobic composter after at least a few months of them being in there.
Commercially compostable
This is where a visual understanding of composting systems helps. Unfortunately, products with “commercially compostable” labelled on them cannot be put in a home composting system. What you use for your garden is an aerobic system, which utilises oxygen-requiring micro-organisms to break down the matter, while industrial composting facilities are anaerobic, which use bacteria not requiring oxygen.
The materials stated as commercially compostable, usually made from sugars and starches i.e. corn and sugar waste, such as coffee cup lids and cutlery, require a perfect balance of heat, moisture, and oxygen to break them down - the anaerobic system. What remains after this degradation is a sludge (typically still requiring aerobic compostion) and methane biogas that is helpfully siphoned off for use as “renewable” energy.
Seeing composting in situ aids in recognising how long materials take to degrade if they are in the incorrect system, and how much value is lost because of this. For example, a coffee cup lid designed for commercial composting, yet placed in a home composter, could have degraded into small pieces after a year, but any beneficial impact from this is unmeasurable and frankly unusuable. The same goes for clothing.
Natural
Natural fibres are those that come from plant and animals (or minerals, in the case of graphene). As they are, they are both biodegradable, and would aerobically compost. The time frame would differ depending on the fibre type, whether it is spun into yarn or woven/knitted into fabric, and if it has any biological dyes or coatings applied to it.
If a natural fibre has been altered with the use of synthetic components i.e. finishes, coatings and dyes, then it will no longer be biodegradable, if we use the definition above that asserts the degradation of biodegradation is non-toxic. It is important here to note that some colourations and finishes can come from plant sources and are therefore not classed as synthetic, though may still be harmful in enough quantity.
Synthetic
Synthetic, or artificial, fibres are those that come indirectly from fossil fuels, through polymerisation. Man-made natural fibres are generally included in this category because they require chemical components in order to make the natural raw material have specific properties e.g. viscose (rayon) comes from wood pulp, though requires solvents to extrude it as a usable fibre.
Synthetic fibres are degradable, though it is said polyester will take 1000 years to degrade fully. During this time, chemical substances will have leached into soil and water, or broken down as harmful gases.
Exploring compostability.
During my MA Fashion and the Environment, I investigated design-for-disassembly, and the Cradle-To-Cradle methodology of “biological cycles” and “technical cycles”. Within this, I adhered to monomateriality - so producing garments that used only natural or only synthetic materials and components. The garment would then biodegrade or be recycled (I’ll come to recyclability in another post…), or ideally be able to be repurposed in its own cycle before eventually coming to its end of life.
One garment that had been designed for this process of composting, was a linen and cotton dress. Unfortunately, it took me many years to access a compost system due to my living situation (no garden), and so the garment only went in for degradation in November 2021.
You could simply put a piece of fabric in the compost and record how long it takes to break down, though I was designing clothing that would be worn first. In hindsight, it wasn’t the best aesthetic, but I was combining craft techniques and materials to invoke a feeling of familiarity (as part of the overall MA thesis), and consequently the garment had a mixture of raw edges, braids, metal hooks, ombré dyeing and seam binding.
Raw edges and visible construction = ability to repair and alter if you can see how something is made
Seam binding = highlighting how the garment was constructed
Layering = multiple layers gives the option to wear the garment multiple ways, or discard one part if it is damaged
Materials:
reclaimed organic cotton poplin
reclaimed undyed plain weave linen
naturally dyed reclaimed organic cotton yarn - dyed with gall nut/blackberry, and with found weeds dandelion and nettle
reclaimed brass picture hooks
GOTS certified organic cotton sewing thread
The concern is the traceability of the organic cotton poplin - was it certified (if not, harmful substances could leach out during the decomposition), and the impact of the brass hooks (metal undergoes lots of processing to make it usable). So though these are all natural materials, chosen for their minimal impact, there could still be a negative impact in the compost.
Due to the size of the compost bay in proportion to my garment - and not thinking of it at the time - I have not undergone any scientific analysis in terms of soil pH for instance, to address whether it had a negative or positive role for the composted matter. My main focus was to see how long it took for the garment to fully decompose in this natural kitchen garden composting system.
It is January 2022, and the compost has yet to be turned. Stay tuned for updates on if and when it disappeared.
Additional resources:
I had the pleasure of speaking with designer-research Cassie Quinn, for the educational platform The Sustainable Fashion Collective. In our conversation, Cassie explains the above terms, along with “biomaterials” and “biodesign”, to help designers recognise how they can actually put these approaches into practice.
"The end-of-life management of waste is a huge and complex problem that sits at the interface of the biosphere and the technosphere. We must find alternative pathways for handling the myriad of natural and synthetic materials embodied in the products we consume," ~ Savanna Browne-Wilkinson of Metabolic Institute.
The Biomimicry Institute, a US not-for-profit organisation, is launching a two-year initiative called "Design for Decomposition” to demonstrate scalable new pathways for the 92 million tonnes of fashion waste discarded annually. It comes as a follow up to their The Nature Of Fashion report from 2020.