How long will this fabric take to decompose?

Originally published June 21, 2023. Updated October 2026.

When we buy fast fashion -- cheap, trendy, and poorly made clothes -- much of it will end up in the landfill. U.S. landfills took in 11.3 million tons of textiles in 2018 alone. What happens to those clothes next depends a lot on what they're made of.

The short answer: plant and animal fibers like cotton, linen, hemp and wool can break down in weeks to months in healthy soil or compost. Synthetic fibers like polyester and spandex are plastic, and they can stick around for decades to centuries. The exact timeline depends on the fabric, how it's made, and where it ends up.

These are estimates, not expiration dates for fabrics. Some figures come from specific experiments, while others are approximate ranges based on the material and available evidence. A finished garment may take longer to break down than a small fabric sample.

When (and where) fabric breaks down best

Microbes do the work of decomposition. They need the right conditions to thrive: warmth, moisture and oxygen help microbes break down natural fibers. An active compost pile or healthy soil can provide these conditions. A landfill is different: waste gets compacted and covered, oxygen becomes limited, and decomposing organic material can generate methane, a potent greenhouse gas. The EPA explains how landfill gas forms.

Wool is a great example of how much conditions matter. Under favorable soil conditions, wool fabric can biodegrade substantially within three to six months. Woolmark reports that Merino wool fabric achieved 95% biodegradation after 15 weeks in soil. But wool preserved in dry or oxygen-poor conditions can last far longer. Archaeologists have even recovered ancient wool textiles.

Climate matters, too. In a study of cotton fabric buried in tropical soil, cotton reportedly broke down within 6 to 10 weeks. That's a useful illustration of how quickly cotton can biodegrade in favorable conditions, but it shouldn't be treated as a universal timeline for every cotton garment.

And the garment matters, not just the fiber. Small fabric pieces generally expose more surface area to microbes than whole garments. Synthetic thread, elastic, zippers and plastic prints can remain after the natural fibers break down. Chemical finishes can also affect biodegradation rates; research on cotton textiles has examined how finishes influence breakdown.

Fabrics that break down

Cotton: about 2–6 months

Cotton is mostly cellulose, the material found in plant cell walls, so microorganisms can break it down. Under favorable composting conditions, small pieces of cotton fabric can break down substantially within 6–12 weeks. In a study comparing cotton and polyester fabrics, researchers found that cotton's breakdown rate depended on its finishing treatments, with some fabrics degrading more slowly than others. Read the research.

The broader estimate of two to six months allows for differences in temperature, moisture, soil conditions and fabric construction. A finished garment may take longer than a small fabric sample, especially if it contains synthetic thread, elastic or chemical finishes.

Organic describes how cotton is grown. It doesn't automatically make the finished fabric break down faster. What happens to the fabric at the end of its life also depends on its dyes, finishes and other components.

That's one reason I use organic cotton in almost all of Jackalo's play clothes. Ideally, our clothes live a long life first, as hand-me-downs or through TradeUp, and only head for composting when they're truly worn out and suitable for it.

Linen: roughly 12 weeks to 5 months, depending on conditions

Linen comes from the flax plant. Research comparing natural textile fibers has found that linen can biodegrade readily in suitable conditions, sometimes faster than cotton. But the exact timeline varies with soil, moisture, fabric construction and finishing, so 12 weeks to five months is a practical estimate rather than a universal scientific benchmark. Read the peer-reviewed research on textile biodegradation.

Linen often comes in soft shades of ivory, tan and gray, and it can be made without dye. It's also long-lasting and tends to soften with age, making it a good choice for clothes that will be worn repeatedly.

Hemp: roughly 12 weeks to 6 months, as an estimate

Hemp fabric is made from the stalk of the hemp plant, a variety of Cannabis sativa cultivated for fiber. Like linen, it contains plant-based cellulose that microorganisms can break down.

A three-to-six-month window is a rough estimate for small, untreated hemp fabric pieces in favorable conditions, not a firmly established timeline for all hemp textiles. Fabric thickness, processing, dyes and the composting environment all affect the result. If you're considering composting hemp clothing, remove synthetic trims and other non-compostable components first.

Wool: about 3–6 months

Wool is a protein fiber. Under favorable soil conditions, it can biodegrade over a period of months and return nutrients to the soil. Woolmark reports 95% biodegradation of Merino wool fabric after 15 weeks in soil.

That doesn't mean every wool sweater will be gone in 15 weeks. Knitting, dyes, finishes and environmental conditions all influence the process. Wool needs suitable moisture, warmth and oxygen to break down; dry or oxygen-poor environments can preserve it for much longer.

Fabrics that stick around

Polyester: decades to centuries or longer

Most polyester clothing is made from PET, the same type of plastic used in many beverage bottles. Unlike cotton, polyester isn't readily broken down by the microorganisms that decompose natural fibers.

In a study by researchers at the Scripps Institution of Oceanography, tested synthetic fabrics showed no visible signs of degradation after more than a year in the ocean. That doesn't establish an exact lifespan of centuries, but it demonstrates how persistent synthetic textiles can be.

Polyester also sheds microfibers during washing and wear. Those fibers can enter waterways and the wider environment, where they may persist for decades or longer.

Spandex: decades or longer

Spandex, also called elastane or Lycra, is a synthetic stretch fiber made from polyurethane-based polymers. Conventional spandex is not readily biodegradable, and there isn't a reliable, universal timeframe for its complete breakdown.

Even a small amount of spandex can complicate composting and textile recycling. In blended fabrics, natural and synthetic components can break down at different rates. The natural portion may degrade while synthetic material remains.

Stretch is useful in many garments, so the goal isn't necessarily to avoid every synthetic fiber. It's to choose materials thoughtfully, buy clothes you'll use for a long time, and keep them in circulation for as long as possible.

Sequins: decades to centuries or longer

I'm seeing more and more sequins on kids' clothes. They're fun, but traditional plastic sequins can persist in the environment for decades or longer, gradually breaking into smaller pieces rather than biodegrading like natural fibers.

Fast Company has explored the environmental impact of sequins, including concerns about plastic waste and alternatives. The precise breakdown time depends on the plastic and the environment, but conventional plastic sequins aren't a great match for compostable clothing.

Quick tips

1. Keep clothes in use first. The greenest garment is one that keeps getting worn. Pass it down, repair it, or trade it in through TradeUP.

2. Choose natural fibers when you can. Cotton, linen, hemp and wool can biodegrade under suitable conditions. Look for clothes that are comfortable, practical and made to last, too.

3. If you need synthetics, make them count. Swimsuits, rain gear and other specialized clothes may need synthetic fibers. Look for recycled options where appropriate, and wash garments thoughtfully to reduce microfiber shedding. Here's our better laundry guide.

4. Don't assume every natural-fiber garment belongs in the compost. Check local composting guidance first. Remove zippers, buttons, elastic, synthetic thread and plastic prints, and only compost fabric when its dyes, finishes and other components are appropriate for the system you're using. Cutting suitable fabric into small pieces can help it break down more readily. The University of Connecticut has a useful composting guide.

5. Skip the sequins when you can. If you love a little sparkle, consider buying secondhand rather than creating demand for new plastic embellishments.

Got another fabric you're curious about? Share it below and we'll add it to this guide.