Per- and poly-fluoroalkyl substances (PFAS)—also known as "forever chemicals"—are everywhere. Created in the 1940s, these synthetic compounds are an unseen ingredient in many items that we use in our daily lives, like cleaning products, food packaging, nonstick cookware, cosmetics, personal care items like dental floss, water-repellent clothing, as well as stain-resistant carpets and upholstery. Since the 1970s, they have also been used in firefighting foams and by the military.