Gore-Tex is a trade name for a breathable, waterproof, and windproof laminate added to clothing and shoe fabrics. The ultra-thin layer(membrane) is bonded with heat and pressure into a coated outer layer that blocks liquid water while allowing water vapour to pass through. The material(mostly polyester or nylon) is designed to be lightweight and waterproof, making it perfect for outdoor clothing, footwear, and accessories.
The Gore-Tex layer is made from a stretched-out form of the PFAS compound polytetrafluoroethylene (PTFE) and is most commonly sewn underneath the upper fabric layer of a garment. The fabric membrane contains millions of tiny holes per inch, and each of these holes is far too small to let through even the smallest water droplet. However, water vapour consists of much smaller particles than liquid water, allowing vaporized sweat to pass through GORE-TEX, resulting in excellent breathability. In addition to the fabric membrane, the manufacturers must use tape to cover the seams and the specialized seam-sealing machinery to ensure a proper seal.
After finishing the garment using Gore-Tex, the manufacturer must send the item to W.L. Gore for certification. The garments undergo rigorous testing to ensure resistance to abrasion and flex, durability in extreme temperatures, and comfort in heavy precipitation. Footwear is subjected to additional tests, including hundreds of thousands of steps in a water bath to check for leaks and proper moisture-wicking performance.
Challenges & Environmental Impact
Gore-Tex is made from polytetrafluoroethylene (PTFE) that originates from fossil fuel; the production process is energy-intensive and requires specialized technologies and the associated greenhouse gas emissions during production. The products are difficult to recycle because the membrane is bonded to other materials. There is no efficient recycling process to separate those materials for the moment.
While durability is beneficial during use, it contributes to long-term persistence in landfills as the materials are not biodegradable.
Gore-Tex membranes use polyfluoroalkyl substances (PFAS) to repel water and dirt. Due to their extreme persistence in the environment, PFAS are considered “forever chemicals.”
To remain effective, Gore-Tex fabric must be treated regularly with durable water repellent (DWR), a toxic chemical spray that wears off over a few years. While DWR is not necessary to keep Gore-Tex waterproof, this substance keeps water off the fabric’s surface, allowing breathability.
PFAS and microplastics can leach out during manufacturing and use, contaminating soil and water and harming wildlife and human health.
Sources
Wikipedia – Gore-Tex 
Sewport – Gore-Tex Fabric
December 2024, RETHINK
