The sites - which range from major chemical plants to universities, food processing centers and hospitals - will need to complete a vulnerability assessment so the government can decide how to regulate their security measures in the future.
U.S. intelligence officials say terrorist organizations, including al Qaeda, favor chemical attack methods because of the severe consequences they can inflict.
"I'm trying to complicate these guys' lives," said Bob Stephan, assistant secretary of infrastructure protection at the Homeland Security Department.
Imposing varying security measures at sites across the country not only secures the materials inside the sites, but it creates a more difficult operation for the terrorists, he indicated.
"This is never going to be an impregnable target set, but I want to introduce enough complexity into the mix that al Qaeda's going to go somewhere else," Stephan told reporters Friday.
Earlier this year, 32,000 businesses with large amounts of chemicals had to complete an online survey that the Homeland Security Department used to determine which facilities' security measures should be regulated. The list was pared down to 7,000. These businesses will go through another vulnerability assessment, and the department will place them into four categories, based on the risk they face.
Homeland security inspectors will eventually visit the highest risk facilities each year to make sure they are complying with enhanced security measures. If these sites do not comply, they could face hefty fines and could ultimately be shut down until they meet federal security standards. As the department considers these 7,000 sites, it also will look at physical security; cyber security; insider threat potential; how hazardous a chemical release could be to the nearby communities; how dangerous the chemicals are if they are mixed with water; and whether the chemicals could be easily stolen from the sites and used to kill.
The list of the 7,000 sites will not be publicly released because of security reasons, the department said.
Congress gave the department the authority to regulate certain chemicals after the Sept. 11, 2001 terrorist attacks.