By 2021, U.S. airports can stop requiring the use of fluorochemicals in firefighting foams, under legislation that President Donald J. Trump signed Oct. 5. A provision in the new law (P.L. 115-254), which renews the authority of the Federal Aviation Administration, is designed to protect drinking water supplies from contamination with poly- and perfluoroalkyl substances (PFASs) that are often ingredients in these foams. Until now, domestic airports had to follow military specifications requiring the use of fluorochemicals in the foams, which are used to suppress liquid fuel fires. “This legislation is a critical first step to allow airports to switch to the less toxic alternatives, which are already being used safely and effectively in other countries,” says Melanie Benesh, an attorney for the advocacy organization Environmental Working Group. The U.S. Department of Defense continues to use foams with fluorochemicals because no commercially available fluorine-free products have met military performance specifications. The U.S. Navy is funding research, development, and testing of fluorine-free foams.