Here in Frederick, MD a fellow was filling a tin gas can at a self-serve place. He was not smoking. He was not using a cel phone (leave me alone, that is what the TV news said). Somehow he caught fire and was killed.
Where was the container when he was filling it – on the ground? On the vehicle? In his other hand?
Just based on the information you provided, I’m going to guess a spark of static electricity. You should always fill the container with it placed on the ground, and the container should be non-conducting.
There is a proper and an improper way to fill a gas can. The nozzle of the filling hose should always stay in contact with the container.
This is something that is not very well publicized or understood. I’ve seen notices like that posted at a few gas stations but very few. It seems obvious to me that every gas pump should have a notice on it with such an instruction.
the container can be plastic or metal and has to be on the ground. your hand not holding the nozzle should be in contact with the container as the nozzle comes near to or away from the container. the nozzle should remain in contact with the container the whole time it is within the opening of the can and while dispensing fuel. safest to keep one hand on the container and one hand on the nozzle with the nozzle well into and tight against the opening of the container during the whole process.
I’ve seen video captures of these fires, while attending OSHA seminars. People with pickup trucks with unlined beds will leave the cans in the beds while they fill them, not grounding them. Or in cold weather they’ll leave the nozzle on auto-fill and get back in their cars, charging themselves with static electriciy on their carpet.
I’ve seen videos of fires igniting at gas pumps when the person pumping the gas leaves the nozzle in the tank, leans into the car to get something, and then goes back to the pump. I read that when the person touched the fabric seat he/she picked up static electricity, which caused a spark when they went back and touched the nozzle. Of course this doesn’t explain the situation you’re talking about, but there may have been static electricity buildup involved somehow.
Some articles said that his Nissan SUV was damaged in the fire, so I’m guessing that the gas can was in it as he was trying to fill it. (If it was on the ground as is recommended, I doubt that the fire would have spread to the vehicle.)