Strict new regulations limiting exposure to so-called forever chemicals take hold in Michigan next week. In New Hampshire, Gov. Chris Sununu in late July signed a bill into law creating some of the nation’s toughest standards for drinking water. Policymakers in statehouses, Congress and the federal government are taking aim at perfluoroalkyl and polyfluoroalkyl substances—commonly called PFAS. There are close to 5,000 types of these man-made chemicals, some of which have been widely used since the 1940s in such products as nonstick cookware, stain-resistant clothing and grease-resistant packaging for fast-food containers. Research over the past few years has shown they pose significant health risks.