The Senate Homeland Security and Governmental Affairs Commitee approved a measure that seeks to tighten security at chemical plants around the country. The bill, which the committee cleared 10-0 on June 15, would require federal performance standards for chemical facilities, with the requirements to vary by plants’ risk levels. It lets states set still-tougher standards if they don’t conflict with the new federal mandates. The panel approved an amendment to require purchasers of ammonium nitrate to register with the Dept. of Homeland Security.

The American Chemistry Council sees the bill as a positive step, but council President and CEO Jack N. Gerard says his group is “concerned the bill allows a potential patchwork of discordant and confusing state-level regulations which will weaken security.”