Can You Compost Clothes? A Guide To Decomposing Old Duds

As a collective we produce 92 million tons of textile waste annually, yet how much of that consists of cotton jeans and t-shirts that could otherwise go into the compost?

If everyone in the US composted their food waste alone, it would be the equivalent of removing 7.8 million cars off the road. Imagine what that number would be if we had a global fashion industry that included circularity and better conditions (or standards like Australia is developing) to compost old clothes.

Composting clothes is cost effective and uncomplicated, and it requires only a repository and the waste you’re already producing.

Clothing made of natural fabrics or organic fibers are typically compostable—and in fact can be an easy way to add brown material to the garden greens.

If you’re not au fait with the benefits of composting—or need a refresher—composting, by definition, is the process of breaking down and repurposing organic waste. It’s nature’s own method of recycling natural waste back into nutritious soil to fuel her cycles. Worms, snails, insects, bacteria, fungi, and microorganisms biodegrade (break down) organic matter (including compostable clothes) and turn it into an earthy substance called humus that gets fed back into the Earth.

For a compost pile to fruitfully produce humus, it needs three things:

1. Browns: Dead plant matter (i.e. leaves) and wood based waste (i.e. twigs, paper, cardboard). This is also the category that clothing falls into. They’re all carbon rich materials.
2. Greens: Live plant material (think food scraps, grass trimmings, fruit cores, coffee grounds, egg shells, and other food waste). They’re all nitrogen rich substances.
3. Water: While most compost creates its own moisture as it does its job, sometimes a little water is needed, particularly in hot climates.

Once covered and left alone, the compost naturally becomes a very hot and moist environment in which it begins its decomposition, eventually becoming nutritious soil.

That said, only certain garments can be composted, due to what they’re made of and how they’re made. Synthetic fabrics cannot be composted. This means anything made of polyester, nylon spandex (Lycra), or acrylics, which are manufactured from petrochemicals and take hundreds (perhaps thousands!) of years to biodegrade, therefore cannot be composted.

Finding clothes that are appropriate for the compost can be tricky; that said, composting clothes is totally possible. It’s also a viable solution to the enormous amount of clothing waste our planet faces. As noted, only clothing that is made from natural fibers can be composted so you’ll have to know how to read clothing labels to determine what fibers that garment is comprised of, looking for the following:

• Natural cotton (ideally organic cotton)
• Silk
• Wool
• Linen
• Cashmere
• Hemp
• jute
• lyocell
• modal
• bamboo fabric

Fabric blends of natural and synthetic fibers are more of a judgment call, depending on the mix and how much synthetic fiber is in the blend. Some reports say a maximum of 1% synthetic fabric is appropriate for composting, while others say it can be 5% or even up to 9%. We say, err on the side of caution and keep it as minimal as possible.

Material isn’t the only thing you need to keep in mind if you’re looking to compost clothing.

Embellishments

Any embellishments like buttons, zippers, snaps, or other metal components won’t be biodegradable (unless they’re specified as made of organic material, like Corozo nut buttons) and will have to be removed.

Don’t forget about the thread! Oftentimes, brands will use polyester thread (because it’s cheaper and stronger) in that 100% cotton t-shirt. For that reason, you’ll often see garment labels stating things like 100% cotton “exclusive of trims”. That doesn’t tell us much, so the safest bet is to rip out threads or cut away thread-intensive sections.

Dyes

Dyes are another common concern for composting clothing, given that many dyes used today are synthetic, toxic, and potentially carcinogenic. Can you compost cotton dyed with these?

Technically yes. Synthetic dyes won’t stop your organic cotton fabric from decomposing, but the chemicals will likely leak out and could contaminate your soil.

What’s tricky here is that we often don’t know if natural fibers were colored using natural dyes. While a label tells us the fabric, the dye ingredients are rarely listed. It’s best to compost clothing that is undyed or from eco-friendly clothing brands that specify if they use plant-based dyes or at least Azo-free non-toxic dyes.

Finishes

Fabric finishes are another consideration when it comes to looking to compost clothes. Fashion brands will coat finished items in chemical finishes to improve the look or performance of the garment. These do things like make the textile stain-, crease-, or water-resistant, anti-microbial, or anti-static. Sometimes they even include fluorocarbons (PFAS), which are very toxic “forever chemicals”.

As with synthetic dyes, these chemical finishes can have a negative impact on your backyard compost, making it unfit for gardening, and sometimes delay the material’s ability to biodegrade.

As with dyes, fabric finishes aren’t typically mentioned on clothing labels, so reach out to brands directly if you think you can compost something, but aren’t sure.

Clothing Tags & Labels

Labels are durable and soft cloth fabric materials, usually made of plastic materials like satin, nylon, taffeta, polyester, tape, or ribbon. Look for cotton fabric tags or tags printed directly on the fabric, but unless it is specified on the tag itself, it’s best to leave clothing tags out.

Stained Fabrics

A final consideration are stains. You don’t want to compost anything that has stains from the “what not to compost” list you can’t wash out, like paint or engine oil.

As a rule of (green)thumb, when in doubt, leave it out. You don’t want to spoil your whole compost batch! (Or go digging through the nasty muck looking for bits of plastic.)

Compostable clothing will be sewn of entirely natural materials and cotton thread, and preferably organic fabrics to ensure a hastened and healthy decomposition. Labels will likewise be made of organic material, like paper or cotton.

Ideally, fabrics and dyes are also certified as organic and/or non-toxic, to verify that they’re all-natural and harmless to the environment. Look for things like bluesign® approval and OEKO-TEX certification, which also tell you something is processed, dyed, and finished in a non-toxic way.

Is Cotton Compostable?

Putting cotton clothes in compost is typically a safe bet. Organic cotton is best, however, as this ensures no toxic dyes, finishes, or other compost contaminating chemicals were used on the fabric.

This includes garments like old jeans. As long as they’re cotton and not blended with a significant amount of synthetics or heavily treated chemically, toss them in. Just ake sure to cut out any rivets, pieces of metal, and leather brand patches.

Denim is also a thicker weave, meaning it’ll break down more slowly than say, an organic cotton t-shirt. Speed up the process by cutting the fabric into tiny pieces.

Is Wool Compostable?

Wool is a 100% natural and biodegradable material. However, its process of decomposing is more lengthy than other compostable clothes and takes up to five years to fully get reclaimed by the earth because of the natural lanolin present in the fibers.

Be sure to rip into into very fine pieces and keep your bin hot and well-ventilated to break this down. You might be better off simply buying this and letting it break down there on its own timeline.

Is Nylon Compostable?

Nope. Sorry to all your old ripped pantyhose! Nylon is neither compostable nor biodegradable. Although nylon is recyclable, it’s expensive and complicated, making it tough to become as mainstream as recycling paper, for example.

The same goes for polyester and elastane/spandex. If you put any of these materials into your compost, it will simply break apart slowly into microplastics and contaminate the rest of your humus.

So, you’ve read the above and your garments check all the boxes. Then let’s get into our formative guide for adding clothes to compost:

1. Read the labels. Make sure it’s one of the previously listed compostable fabrics.
2. Make sure it has no toxic stains. If you’re composting clothes like cloth eco-friendly diapers, be sure to wash so that no feces remains before composting.
3. Trim out any non-compostable embellishments, like zippers, clothing tags, plastic buttons, rivets, etc. Sometimes collars, cuffs, thread, or hems are likewise non-compostable. Remove.
4. Choosing to compost shredded clothes is better than full garments, because the material breaks down faster. If you don’t have a shredder, scissors work just fine. This may be time-consuming, but it’s worth it.
5. Toss your cut-up bits of clothing into your home compost. It shouldn’t account for more than 25% of your compost pile, to ensure it breaks down properly.

You’ll also want to be mindful of your greens vs. browns and the moisture content of your compost. Clothing, which are “browns”, are carbon-rich and take longer to decompose than nitrogen-rich “greens”.

Because clothing is made to stay durable, it will probably take a while for the clothing to compost, even after cutting it up into small pieces.

Ultimately, however, how long it takes clothes to compost depends on what type of fabric it is and the conditioners of your composter. A 100% cotton T-shirt will usually decompose within a few months, and linen can biodegrade as quickly as two weeks, while other natural fibers like wool may take a bit longer.

Commercially Composting Old Clothes

Sometimes compostable clothing may require a commercial composting facility. This is because heat is created naturally in the process of composting, which along with moisture, helps break down matter. Many home compost bins don’t get hot enough for your old apparel to biodegrade at the optimal speed.

Commercial textile composting, while still severely lacking in infrastructure, cultivates a much more optimal composting environment to compost clothes. If you have access to such a service, follow the same steps for backyard composting your clothes (reading labels, removing hardware, cutting into small pieces, etc).

Remember, you can always contact both the clothing brand and your local industrial compost facility to determine the best end-of-life for your clothes.

The dirty truth is that unless you shop exclusively for compostable clothing brands, many items in your closet probably can’t be composted.

For example, most socks or underwear and bras have a significant amount of spandex and polyester in them to add comfort and stretch, or are made of lace or other frills that are toxic to the planet. Likewise, most activewear, formal wear, and outerwear is created with synthetic materials that cannot decompose, so how can we responsibly dispose of these?

Of course, it depends on how used the item is. For example, we’d never suggest donating or reselling highly worn, torn, and stained clothing items. Beyond finding them a new home, consider the following reuses for old clothes:

• Use a brand’s “Return and Recycle Policy”.
• Make reusable cleaning rags.
• Repair old clothes, either yourself, through a tailor IRL, or one online.
• Up your upcycled clothing skills and either transform them into something new to wear or into
• non-wearable items. The possibilities are endless, from decorations and reusable gift wrapping to boho chic placemats or rugs.
• Recycle old clothes through organizations like B.R.A, Planet Aid, or Terracycle.