Something in the air

   How dangerous is a spray can of compressed air? It’s just air, right?
   Wrong. These pressurized cans actually contain hazardous gases, which differ from product to product, and must be handled with the utmost care when prepared for air transport, explained Hank Baird, general manager of ATP Training, a subsidiary of AllTransPack.
   “The conditions in air transport are different than with other modes,” Baird said. “There are pressurization issues due to altitude and temperature differentials. Also, there is the concern of vibration due to takeoff, landing and severe turbulence.”
   In its final report on the ValuJet crash in the Florida Everglades in 1996, the National Transportation Safety Board stated the jostling caused by the plane’s taxiing and takeoff most likely caused undeclared oxygen generators inside the baggage hold to ignite.
   “When the regulators put together the requirements for offering any hazardous material for air transport, [flight] conditions, as well as the uniqueness of the air mode as a whole, are taken into consideration,” Baird said.
   He noted that in the case of the air-blast sprays, which are used to clean dust out of keyboards and off electronic circuit boards, if the gas used is 1,1-Difluoroethane, co-mingling it with anything alkali-based can result in a chemical reaction. “Additionally, as with any flammable hazardous material offered as undeclared, the risk of loading and storing the material next to or near a source of heat is a constant,” he added.
   Despite the hazards related to compressed air cans, they can be shipped by air transport if the product has received a Special Permit (SP) from the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA), which is essentially a “permission slip to break the rules,” Baird said. (For air-blast cans used to clean computer keyboards and circuit boards, the Special Permit number is SP-11516, which is printed on each of these canisters.)
   “Once granted, the SP, just like the regulations overall, must be adhered to in all respects,” he said. “In the case of SP-11516, the product is restricted to cargo aircraft only. But if a shipper is not fully aware, it is easy to misidentify and prepare it so it can be moved on passenger flights.”
   AllTransPack, which is based in Sterling, Va., processes many hazardous materials shipments, including air-blast cans, for various U.S. government agencies that order products online from suppliers like Grainger. These hazardous materials are shipped by all transport modes, including air, to embassies and military installations throughout the world.
   To offer these cans for air transport in a compliant manner, Baird said an individual must first be properly trained on 49 CFR subpart H to part 172 and also be trained and tested on the requirements for the PHMSA Special Permit (SP) [172.702(a) of 49 CFR and paragraph 11 of DOT SP-11516]. In addition, the International Civil Aviation Organization (ICAO) Technical Instructions for the Transport of Dangerous Goods by Air, as communicated via the International Air Transport Association’s Dangerous Goods Regulations, must also be followed.
   The Federal Aviation Administration (FAA) and PHMSA, both within the U.S. Department of Transportation, are the “overseers” of the requirements—FAA for the air standards and both FAA and PHMSA for the SP—Baird said. DOT authorizes the use of the ICAO technical instructions for hazardous materials air shipments, provided the shipper meets all the applicable additional requirements of the FAA.
   “One common mistake by somewhat knowledgeable shippers when offering air-blast spray cans for air cargo is their offering it under the proper shipping name, ‘aerosols, flammable,’ which is permitted to be carried on passenger aircraft, while the SP states specifically that the product is restricted to cargo aircraft only (CAO),” Baird said.
   “The product is CAO either because it is a safety precaution by PHMSA as the gases are not in containers that meet the normal specifications of part 178 of 49 CFR, or because the gas being used is so flammable that it is not permitted to be transported on a passenger-carrying flight even when it is in the normally required specification container,” he said.