PFAS 101: What Are PFOS & PFOA? Did you know perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the “forever chemicals” behind heat- and water-resistance? They’re the reason your takeout boxes stay glossy, your nonstick pans work, and your rain gear repels water. High-Risk Source: Aqueous Film-Forming Foam (AFFF) • Used in firefighting drills and on airfields • Packed with PFOS/PFOA chains—the strongest bonds in chemistry • Can build up in your body over time If you handled A