Laptops in checked baggage also pose risks, U.S. government says

WASHINGTON — The U.S. government is urging the world airline community to ban large, personal electronic devices like laptops from checked luggage because of the potential for a catastrophic fire.

The Federal Aviation Administration said in a paper filed recently with a UN agency that its tests show that when a laptop’s rechargeable lithium-ion battery overheats in close proximity to an aerosol spray can, it can cause an explosion capable of disabling an airliner’s fire suppression system. The fire could then rage unchecked, leading to “the loss of the aircraft,” the paper said.

The UN agency, the International Civil Aviation Organization, sets global aviation safety standards, although member countries must still ratify them. The proposed ban is on the agenda of a meeting of ICAO’s panel on dangerous goods being held this week and next week in Montreal.

The FAA has conducted 10 tests involving a fully-charged laptop packed in a suitcase. A heater was placed against the laptop’s battery to force it into “thermal runaway,” a condition in which the battery’s temperature continually rises.

In one test, an 8-ounce aerosol can of dry shampoo —which is permitted in checked baggage — was strapped to the laptop. There was a fire almost immediately and it grew rapidly. The aerosol can exploded within 40 seconds.

The test showed that because of the rapid progression of the fire, Halon gas fire suppressant systems used in airline cargo compartments would be unable to put out the fire before there was an explosion, the FAA said. The explosion might not be strong enough to structurally damage the plane, but it could damage the cargo compartment and allow the Halon to escape, the agency said. Then there would be nothing to prevent the fire from spreading.

Other tests of laptop batteries packed with potentially dangerous consumer goods that are permitted in checked baggage like nail polish remover, hand sanitizer and rubbing alcohol also resulted in large fires, although no explosions.

Rechargeable lithium batteries are used in consumer products ranging from cellphones and laptops to electric cars. Manufacturers like them because they pack more energy into smaller packages, but the batteries can self-ignite if they have a manufacturing flaw, are damaged, exposed to excessive heat, overcharged or packed too closely together. The fires can burn up to 1,100 degrees F, close to the melting point of the aluminum used in aircraft construction.