Patagonia—as well as other high-quality outdoor outerwear suppliers—for years relied on a Durable Water Repellent (DWR) of a certain chemistry (described below) to bead up, then disperse, surface moisture from rainwear. It is necessary, even in a waterproof jacket, to prevent surface saturation. A soggy surface creates a clammy, wet-feeling next-to-skin climate even where water does not actually penetrate the surface. The DWR we used as a standard for years was a long-chain (C8) fluorocarbon-based treatment that is highly effective and extraordinarily durable. Unfortunately, its by-products are toxic and persist in the environment, a combination that makes it unacceptable despite its excellent performance. Governments around the globe have now required chemical companies to stop making C8 DWR, so every high-quality outerwear supplier has been searching for alternatives of comparable performance.
For the past decade, we’ve carefully researched and tested every available fluorocarbon-free alternative. Many finishes—including waxes and silicones—will lower the surface tension of a fabric enough to cause water to bead up and disperse rather than saturate. But they are easily contaminated by dirt and oil and rapidly lose their effectiveness, reducing the effective lifetime of a garment.