Since Patagonia introduced its fleece Synchilla jacket in 1985, the cozy, lightweight synthetic fabric has become a go-to for outdoorsy types. Now, this warm and affordable material is giving environmentalists a chill. Here's why: Each time fleece gets washed, thousands of tiny plastic fibers are released and ultimately end up in rivers and oceans, where they work their way through the food web. What's an eco-conscious fleece lover to do? First, don't launder so much—this extends the life of a garment while reducing energy and water use as well as the shedding of fibers. Then look into outerwear alternatives.

Photo by Lori Eanes

No need to ditch your fleece garments—there's a German innovation designed to keep microfibers out of waterways: The GUPPYFRIEND Washing Bag, funded by Patagonia, allows water and detergent to enter, but prevents nearly all of the fibers from escaping. Just stick your fleece in the sack, wash as usual, and then dispose of the residue inside the bag. (The effects of microfibers in solid waste are yet to be determined, but collecting the tiny particles is undoubtedly better than sending them straight into the water system.) Comes in one size: 19.7 x 29.1 inches. Made from untreated Polyamide 6.6 nylon. $35, guppyfriend.com

BLACK DIAMOND's Alpenglow Sun Hoody is treated with a product containing recycled silver chloride for odor control (less washing required). $79, blackdiamondequipment.com

SMARTWOOL's Echo Lake Half Zip Sweater has a wool base and a bit of itch-free fleece inside. $150, smartwool.com

STIO's Pinion Down Sweater has responsibly sourced goose down insulating its nylon shell. $229, stio.com

PATAGONIA's Clean Color Sweatshirt is made from organic cotton and plant-derived dyes, with minimal fleece. $69, patagonia.com

This article appeared in the January/February 2018 edition with the headline "Don't Get Fleeced."