Dozens of mislabeled chemical oxygen generators most likely fueled the rapid spread of the explosive fire at the EQ Industrial Services facility in Apex last fall, U.S. Chemical Safety Board investigators said Wednesday.

The discovery in the rubble of the highly volatile devices, which supply emergency oxygen to airplane passengers, was important enough that the Chemical Safety Board issued an alert to aircraft maintenance facilities and hazardous waste handlers.

Oxygen generators feed the face masks that drop if the cabin loses pressure, but they must be replaced at the end of their service life. Even after they've expired, they remain explosive until deactivated. Improperly shipped oxygen generators in the cargo hold were identified as the probable cause of a fire aboard the ValuJet airliner that crashed in the Florida Everglades in 1996.

The fire at the EQ hazardous waste facility in October shrouded Apex in a chemical cloud and forced thousands to flee their homes.

The generators involved in the fire came from ST Mobile Aerospace Engineering, a large aviation maintenance company in Mobile, Ala. Aircraft maintenance workers had removed expired but still-volatile generators from planes. Mobile Aerospace placed the packaged metal canisters, which are about 8 to 9 inches long, inside steel drums and shipped them to PSC Allworth, a hazardous waste facility in Birmingham, Ala.

PSC Allworth misidentified the oxygen generators on shipping manifests, the safety board said. The company repackaged the canisters in a large cardboard box and shipped it to EQ, investigators said.

Robert Hall, lead investigator for the Chemical Safety Board, said PSC should not have accepted the oxygen generators as hazardous waste, because they had not been deactivated. Even after their expiration dates, they remain hazardous because of an explosive mechanism that triggers the release of oxygen.

"They really did not recognize the hazard that these things posed," Robert Hall said.

Officials at PSC Allworth did not respond to requests for comment.

Joe Delcambre, a spokesman for the Pipeline and Hazardous Materials Safety Administration, a federal agency that regulates hazardous waste shipments, said the agency was continuing its inquiry to determine whether to levy civil penalties against Mobile Aerospace or PSC Allworth.

At EQ hazardous waste transfer depot, the oxygen generators were stored four months and eventually placed in the same location as solid chlorine-based pool chemicals awaiting final disposal, the chemical safety board said.

Hall said investigators are still looking into what triggered the fire. He said the oxygen generators were stored in the area where the fire is believed to have started. The generators can be activated by heat, causing the release of oxygen.

EQ Industrial Services issued a statement noting the safety board's findings. "In light of this information and the subsequent safety advisory from the CSB, we are confident that the public and industry will benefit from the resulting increased safety precautions," said Robert Doyle, EQ's spokesman.

Hall said investigators are still trying to understand why the canisters remained at the EQ facility for months and why they were shipped from one waste transfer facility to another, rather than to a disposal site. Hall said some EQ staff told investigators that they were aware there was a box of oxygen generators on site, but did not know whether they had been deactivated.

No fire suppression

Chemical Safety Board investigators also have noted that the EQ facility did not have a fire suppression system or fire walls to prevent the spread of fire from one storage bay to another.

"We believe that even with the oxygen generators fueling the blaze, had the facility had an automatic fire suppression system and fire walls, this accident may have been avoided," said William Wark, a member of the Chemical Safety Board.

As a result of the massive fire, state lawmakers adopted tighter regulation of hazardous waste disposal facilities, including a requirement that they have 24-hour security, more frequent permit reviews and better communication with neighbors on proposed changes to the operating permits.

The Chemical Safety Board is an independent federal agency charged with investigating chemical accidents. It doesn't issue fines or penalties.

But the board issued a rare urgent recommendation to Mobile Aerospace, calling on the company to revise its procedures to ensure that oxygen generators are deactivated before shipping. It also urged the company to ensure that hazardous waste is correctly described on shipping manifests.

Alan Hall, risk manager for Mobile Aerospace, said the company was still investigating why the oxygen generators had not been expended before shipment.

"I don't have an answer for that right now," Hall said. "That is an internal investigation. We're expending them now and have been for several months since being notified by the Chemical Safety Board."

"We want this not to occur any place else," Hall said.

EQ, headquartered in Michigan, is fighting North Carolina environmental regulators' efforts to terminate its hazardous waste storage permit. It has been told by the Apex Town Council that it cannot rebuild its warehouse in town.

"While it is very troubling to learn that such dangerous materials were stored at this location, CSB is to be commended for issuing this safety advisory, as the volatility of these materials is truly frightening," said Apex Mayor Keith Weatherly. "We can but hope that other communities can learn from our local incident and join us in the efforts to ensure the appropriate siting of such facilities away from residential populations."

Get $150+ in coupons in every Sunday N&O. Click here for convenient home delivery.