Responding to congressional and public criticism, federal regulators said Friday they would not weaken rules requiring certain disclosures about trains transporting crude oil and other hazardous materials.

The Inquirer reported this week that new oil-train rules issued May 7 - to go into effect in October - by the U.S. Department of Transportation would end a 2014 requirement for railroads to share information about large volumes of crude oil with state emergency-response commissions.

Instead, railroads were to share information directly with some emergency responders, but the information would be exempt from the Freedom of Information Act and state public records laws.

"Under this approach," the proposed rule said, "the transportation of crude oil by rail ... can avoid the negative security and business implications of widespread public disclosure of routing and volume data. ..."

But the federal Pipeline and Hazardous Materials Safety Administration, an arm of the Transportation Department, said Friday it would not make the change.

The existing rule "will remain in full force and effect until further notice while the agency considers options for codifying the May 2014 disclosure requirement on a permanent basis," the agency said.

Saying that "transparency is a critical piece of the federal government's comprehensive approach to safety," the agency said it supported "the public disclosure of this information to the extent allowed by applicable state, local, and tribal laws."

U.S. Sen. Robert P. Casey (D., Pa.) was one of nine senators who asked the agency to keep the existing rule in place. Casey said he was pleased by the agency's decision.

"First responders who risk their lives when trains derail deserve to know what chemicals they could be dealing with when they get to the scene," Casey said in a statement.

The disclosure rules about train routes and general numbers of trains apply to all trains carrying one million gallons or more of crude oil from the Baaken oil deposit in North Dakota.