Water repellency doesn’t just keep you comfortable, it keeps you alive. But for decades now, the DWR (durable water repellent) finishes used in clothing to help moisture bead up and roll off the outer surface have relied on per- and polyfluoroalkyl substances, a.k.a. PFAS. These synthetic chemistries have one of the lowest surface energy of any known material. Basically, they repel everything. That’s great for engineering. But, as recent research shows, they’re toxic. The primary issue is in the