Center for Biological Diversity

For Immediate Release, April 19, 2023


Stephanie Feldstein, Center for Biological Diversity, (734) 395-0770,
Emma Hakansson, Collective Fashion Justice, +61 401 629 297,

Analysis Finds Most Wool Knitwear Is Blended With Plastic

Processing, Blending Undermine Sustainability Claims of Wool

NEW YORK, N.Y.— More than half of wool knitwear is blended with synthetic fibers derived from fossil fuels, a new analysis by the Center for Biological Diversity and Collective Fashion Justice has found.

Too Hot for Knitwear: Climate Crisis, Biodiversity and Fashion Brands Using Wool and Synthetics analyzed the Fall 2022 online catalogs of 13 top high street and luxury fashion brands. The analysis found that while wool is often marketed as a natural, sustainable alternative to synthetics, most wool garments are mixed with synthetic materials, contributing to microplastic pollution and worsening the climate crisis.

“The fashion industry has tried to pass wool off as a sustainable alternative to synthetics, but that claim quickly unravels when you take a closer look,” said Stephanie Feldstein, population and sustainability director at the Center. “Even 100% wool fiber production leads to deforestation and threatens wildlife. There are real eco-friendly materials out there, but wool isn’t one of them.”

The analysis revealed that 55% of examined wool items were blended with synthetic fibers. Only 19% contained reduced-impact fibers, most commonly recycled synthetics, which still shed microplastics into the environment. The use of wool blended with virgin or recycled synthetic materials — and the likelihood of wool being chemically washed, processed or dyed with substances impacting biodegradation — negate any potential benefits of using such a “natural” fiber.

The analysis also found that high street brands were more than twice as likely to use synthetics in wool knitwear and 26 times more likely to offer 100% synthetic knitwear, though more than one-third of analyzed luxury knitwear also used synthetics. Overall, 90% of analyzed knitwear items used wool, despite the availability of truly sustainable fibers like Tencel that can meet the quality, aesthetic and performance needs of knitwear.

“Making knitwear from wool-synthetic blends gets us the worst of both worlds,” said Emma Hakansson, founding director at Collective Fashion Justice. “It takes emissions from fossil fuels and enteric methane, biodiversity destruction, plastic pollution, and animal cruelty and wraps them all up in one piece of clothing.”

This analysis follows a report released last year on wool production’s devastating harms to wildlife and the environment. Shear Destruction: Wool, Fashion and the Biodiversity Crisis found that producing one kilogram of wool can create as much climate pollution as driving more than 100 miles and one bale of Australian wool uses up to 367 times more land compared to cotton.

The Center for Biological Diversity and Collective Fashion Justice are calling on the fashion industry to increase transparency around the environmental impacts of wool and to shift beyond both fossil-fuel and animal-derived materials. This just transition is increasingly possible as plant-based, bio-based, recycled and other innovative and responsible alternatives enter the market.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

Collective Fashion Justice is an international not-for-profit dedicated to creating a total ethics fashion system, prioritizing people, our fellow animals and the planet we share before profit.

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