On December 17, 2015, the U.S. Senate passed S. 697, the Frank R. Lautenberg Chemical Safety for the 21st Century Act, which would amend the Toxic Substances Control Act. This long-awaited Senate action on TSCA reform had been delayed due to efforts by Senator Richard Burr (R-North Carolina) to attach an unrelated amendment. The bill now must be reconciled with the House of Representative’s TSCA reform bill, H.R. 2576, which the House approved in June. The most significant challenge likely will be reconciliation of the bills’ preemption provisions, with Senator Barbara Boxer having voiced significant concerns over state rights to regulate chemicals.