Updated

After years of policing itself, the nation's chemical industry may face broad federal regulation of security at its plants to safeguard against terror attacks.

Under a draft Senate plan obtained by The Associated Press, chemical plants that fail to create, update and submit security plans for their facilities could be shut down by the Homeland Security Department.

The draft bill addresses some longtime concerns about vulnerabilities at the nation's 15,000 privately operated chemical plants. It would expand federal regulatory authority over chemical plants, but set no specific minimum standards that the industry would have to meet in securing its facilities.

Counterterror experts put the chemical industry at the top of the list of likely terror targets. Currently, the chemical industry regulates itself with voluntary measures to secure plants from terrorism, but congressional investigators have revealed spotty results in how well the industry is prepared to respond if there is an attack.

About one-fifth of the nation's chemical facilities are close to population centers. Homeland Security has identified 297 chemical facilities where a toxic release could affect 50,000 or more people.

Under the draft legislation, which may still be changed, chemical manufacturers would be required to assess potential security gaps and tailor specific solutions on a plant-by-plant basis. Both the assessments and solutions — which could include measures like surveillance cameras or limited access to certain areas — would then be submitted to Homeland Security for approval.

Chemical manufacturers would also be required to create or update existing emergency response plans.

Repeated failures to comply could lead the Homeland Security secretary to "issue an order for the chemical source to cease operation," according to the most recent draft of the legislation.

In turn, Homeland Security would be required to develop certain security standards for plants that would be grouped into tiers, based on the level of risk they pose to surrounding communities.

The Senate is expected to begin considering a final copy of the legislation in coming weeks. But its fate is uncertain in the House, where majority Republicans so far have shelved plans to expand federal authority over chemical plants.

Homeland Security spokesman Russ Knocke said Thursday the department has been working with chemical manufacturers to ensure plants are secure. He declined to comment on the draft, but said the department is "looking forward to working with both the House and the Senate on this issue."

The chemical industry has traditionally resisted governmental regulation. But American Chemistry Council security director Marty Durbin on Thursday said the group welcomed the draft plan, which "will make sure that those facilities that need to be taking actions here are doing so."

"And, at the end of the day, if they don't, you can shut them down," Durbin said. His group represents 2,000 chemical plants nationwide.

Security standards at nuclear power facilities and commercial airports are already federally regulated, but regulation for chemical plants is far spottier. The Coast Guard regulates some security measures at chemical facilities on waterways, while the Transportation Department oversees standards for moving chemicals to and from plants.

The draft was written by Republicans. Democrats, including New Jersey Sen. Jon Corzine, have long called for greater federal oversight at chemical plants. But spokesman Anthony Coley said Corzine, who was elected last month as New Jersey governor, is concerned that the federal oversight might override state regulations already in place.

Additionally, some environmentalists have objected to language in the draft that does not specifically require manufacturing plants to use certain kinds of chemical materials that would be less dangerous to the public in an attack or accidental release. Jen Burita, spokeswoman for Sen. Susan Collins, R-Maine, said the draft does require "chemical facilities to take steps to reduce consequences."

Collins, chairwoman of the Homeland Security and Governmental Affairs Committee, is expected to issue a final copy of the legislation shortly.