HOUSTON (AP) -- Federal and state officials investigating last week's deadly blast at a Central Texas fertilizer company are trying to determine whether a fire at the plant could have ignited a supply of ammonium nitrate. But how much of the highly explosive fertilizer was stored at the site is unclear because of a gap in federal regulations.
The gap indicates that measures taken after the 1995 Oklahoma City bombing and the Sept. 11, 2001, attack to monitor potentially dangerous substances have been less effective than anticipated. The investigation of the blast at the West Fertilizer Co., which killed at least 14 people, has focused new attention on the regulation of chemicals that pose safety or terrorism concerns.
"We don't know what chemicals were there, we don't know what chemicals are there, and at this point, we do not know the quantities that were on hand at the time of the incident," Kelly Kistner, Texas assistant state fire marshal, told reporters.
After the 2001 attacks, the Department of Homeland Security began requiring all companies with more than 400 pounds of ammonium nitrate to register with the agency. The fertilizer was used in the bomb that destroyed the Oklahoma City federal building in 1995, killing 168 people.
Officials say the owners of West Fertilizer did not register. But they also said they don't know whether the company needed to do so. According to state records, it had the capacity to store 270 tons of the chemical.
If a facility failed to meet the requirement, it could be shut down, the DHS said. But the agency doesn't investigate facilities that haven't filed reports.
"We know what we know," DHS spokesman Peter Boogaard said, noting the system is self-regulating.
In 2007, Congress authorized DHS to make more stringent rules for transactions involving ammonium nitrate. A year ago, a regulation was posted for public comment in accordance with the federal rulemaking process.
And there it stalled, for reasons that remain unclear.
"Industry was firmly behind it. We knew we needed to raise the bar on ammonium nitrate or we were going to have an incident," said Daren Coppock, president of the Agricultural Retailers Association, a Washington, D.C.-based nonprofit trade group.
The rule would require anyone who buys or sells ammonium nitrate to register with the department. "So the question of whether West had ammonium nitrate on its property would have been answered," he said.
Many states, including Texas, have agencies that track ammonium nitrate. But there is no formal system or requirement for providing the information to the federal agency, and the Texas agency was not focused on safety.
The owners of the plant in West, the Adair Grain Co., have released a statement saying they are cooperating with the investigation, but have not responded to requests for further comment.