WASHINGTON, Aug. 3 (UPI) -- A 3-year-old law mandating stricter controls on a fertilizer used by terrorists in explosives has yet to be implemented, officials say.
Under the law, dealers and purchasers of the ammonium nitrate fertilizer, which terrorists mix with fuel to create explosives, would be required to register with the government and be checked against a U.S. terrorist database, USA Today reports.
The law also requires dealers of the fertilizer, the main ingredient in the 1995 Oklahoma City truck bomb, to report its loss or theft.
The Department of Homeland Security, which is to enforce the law, said it is devising rules for more than 100,000 users, including agriculture, construction and mining.
The agency published proposed rules Tuesday, and industry representatives and the public will have four months to comment before the rules become final. No date has been set for making the rules permanent.
"In today's ever-evolving threat environment, we must continually reinforce the security of substances, such as ammonium nitrate, which can be used for legitimate purposes or exploited by terrorists," Homeland Security Secretary Janet Napolitano said.
Some lawmakers expressed disappointment the law hasn't taken effect sooner, the newspaper said.
"I am disappointed that more progress has not been made to put reasonable protections in place … since we acted to fix this in 2007," said Mississippi Rep. Bennie Thompson.
Last month, a 32-year-old man allegedly bombed an Oslo government office building, using an ammonium nitrate explosive, and the bombing, along with shooting, caused 77 deaths.