CSB: Unspent Aircraft Chemical Oxygen Generators Pose 'Imminent Hazard'
The U.S. Chemical Safety Board issued a safety advisory concerning the dangers of transporting and handling unspent aircraft chemical oxygen generators. The action follows a CSB investigative finding that the devices most likely contributed to the rapid spread of a fire at a hazardous waste facility in Apex, North Carolina, on the night of October 5, 2006. The fire resulted in the evacuation of thousands of residents of Apex, located about 16 miles southwest of Raleigh, and destroyed the facility's hazardous waste building.
Chemical oxygen generators are used in commercial aircraft to supply supplemental oxygen to passengers in drop-down masks should the cabin depressurize. They are similar to the ones that started a fire in the cargo compartment aboard an airplane that crashed in 1996 in Florida. The National Transportation Safety Board investigation report of that accident stated that expired but fully functioning chemical oxygen generators should be expended before being transported.
The devices that contributed to the North Carolina fire were past their projected service life but remained fully charged and hazardous. They originated at an aircraft maintenance facility in Alabama that did not expend the contents prior to transport. In addition, shipping documents did not identify them as unspent chemical oxygen generators as required by DOT regulations.
At a news conference held in Raleigh, CSB Board Member William B. Wark said, "We issued this advisory to alert aircraft maintenance and hazardous waste facility personnel to the hazards associated with transporting and storing expired but unspent aircraft oxygen generators. These can be very dangerous and if mishandled can cause fires, property damage, and personal injury."
Lead Investigator Robert Hall, P.E., said, "Our investigation found that the unspent oxygen generators were stored in the area where the fire is believed to have originated. The generators can be activated by heat, which results in the release of oxygen, further accelerating and intensifying the fire. When firefighters first arrived, the fire was small. But it quickly spread to an adjacent bay."
Chemical oxygen generators in passenger aircraft have a limited useful life and must be periodically replaced. Even after their expiration dates, they remain potentially hazardous materials. In this case, the CSB found, an aircraft maintenance facility in Alabama sent the chemical oxygen generators to a hazardous waste facility in Birmingham without activating and expending the contents as recommended by the NTSB. The receiving hazardous waste facility misidentified the oxygen generators as general oxidizer waste on shipping documents they prepared for the aircraft maintenance facility.
The CSB issued an Urgent Recommendation--the third in the agency's history--to the maintenance facility. Urgent recommendations are issued when in the view of the CSB Board Members there is an "imminent hazard." This recommendation urged the aircraft maintenance company to revise or develop procedures to ensure the generators are expended before shipping, revise as necessary procedures for assuring hazardous waste is correctly described on shipping manifests, and communicate to all of its waste brokers and waste facilities that the incorrect shipping name and code was or might have been used for unspent oxygen generators shipped from its facility. The CSB investigation continues with a final report planned to be released by the end of the year.