Expanded polyethylene (ePE)

Why

Membranes are a sometimes overlooked but critical component of waterproof gear. Bonded to the inside of your gear’s exterior shell, this thin inner layer of material has holes that are small enough to keep water from seeping in, but not so small that sweat can't vaporize out. For years, some membranes were made from expanded polytetrafluoroethylene (ePTFE)— an extremely hydrophobic and durable material. They worked well, but there was a problem: ePTFE is made with perfluorinated chemicals (commonly known as PFCs and PFAS). Though safe in finished products, these synthetic compounds can end up in the air and water during manufacturing processes. They’ve also been linked to increased cancer risk. And the compounds don’t break down. Perfluorinated chemicals remain in the environment—and in our bodies—indefinitely. We needed to come up with an alternative.

Where We Are

Now 100% of our styles are made without intentionally added PFAS—a journey 14 years in the making. We partnered with GORE-TEX to build waterproof gear without PFAS for the most technical mountain outdoor sports. These non-fluorinated products would have to withstand the most extreme conditions of snow and backcountry terrain, while also keeping you dry, comfortable and protected. Achieving that level of uncompromising durability has been challenging, but thanks to GORE-TEXs research, development and testing—and our own rigorous tests in the lab and field—we’re finally there.

In Fall 2022, we were the first outdoor brand to launch a limited run of GORE-TEX’s first 2-layer ePE material in our Storm Shift Jacket and Pants built with GORE-TEX’s expanded polyethylene (ePE) series. This new material eliminated the need for long-lasting perfluorinated chemicals while still meeting Patagonia and the GORE-TEX brand’s high standards* for waterproof and windproof protection, as well as breathability.

For Fall 2023, we introduced a 3-layer iteration of GORE-TEX ePE that could withstands the most rugged and demanding mountain experiences for some of our pinnacle technical Alpine and Snow pieces: the Triolet Jacket and Pants, the Super Free Alpine Jacket, the Alpine Suit, the Untracked Jacket and Bibs, and the Storm Shift Jacket and Pants.

In Fall 2024, we added the 2-layer Insulated Storm Shift Jacket and Pants to our line, plus the 3-layer Untracked Pants—all made with GORE-TEX'’s ePE fabrics. In Fall 2025, we incorporated 3-layer GORE-TEX (ePE) Pro fabric into our PowSlayer Jacket and Pants.

We’re proud to make gear without intentionally added PFAS. Read more about our journey here.

What’s Next

ePE is part of Patagonia’s broader goal to shift toward making gear without perfluorinated chemicals across all of our products by 2025. As we find more responsible options, we hope to inspire others in the clothing industry to redefine what’s possible for waterproof gear.

*For more on GORE-TEX's sustainability goals, see https://gtx.is/pfcec.