Venting Propane Tanks Ignite During Slash Burning
BACKGROUND: Burning piled slash in the fall and spring is a standard silvicultural practice in the Northwest. One method of burning involves hand lighting slash piles. On a warm fall day at an Inland West location, a forester had ridden an all-terrain-vehicle to an area inaccessible by pick-up and was igniting slash piles with a hand-held torch.
PERSONAL CHARACTERISTICS: The forester had ten years' experience and had burned piles many times in the past. He was considered fully trained.
NEAR MISS: Earlier that morning he had attached the torch to a two-gallon propane tank that was slightly overfilled. The forester set the propane tank down and was igniting a pile of slash when the torch passed close to the tank. The tank was venting propane that ignited. The forester, fearing an explosion, left the tank on the ground and ran 150 feet to the ATV only to find there was no fire extinguisher. He grabbed his coat from the ATV, ran back to the burning tank and smothered the fire. He could have been burned attempting to put out the fire. Overfilled propane tanks sometimes explode, resulting in severe injuries.
CAUSE OF NEAR MISS: To allow for expansion, propane tanks should not be filled beyond 80 percent capacity. In this case, the fittings had been properly installed and were tight, but the overfilled tank was venting through a bleeder valve. The forester had not tested the fittings for leaks and was unaware of the venting condition (it may not have been venting at the time the fittings were connected).
RECOMMENDATIONS FOR CORRECTION:
Please follow equipment manufacturers’ recommendations for safe operation and maintenance procedures.