The Senate's bill, passed last month, just before the holidays, is particularly restrictive. The Frank R. Lautenberg Chemical Safety for the 21st Century Act — named, ironically, for the New Jersey senator who supported strong environmental protections — would make it much harder for states to regulate chemicals after the EPA has evaluated them, and would even prohibit states from acting while the federal agency is in the process of investigating certain chemicals.

The Senate's version has some significant differences from the House bill — the TSCA Modernization Act, which passed in June — and the reconciliation process is now underway. If the worst provisions from both bills wind up in the final law, which could reach the president's desk as soon as February, the new legislation will gut laws that have put Oregon, California, Maine, Vermont, Minnesota, and Washington state at the forefront of chemical regulation.