I quote:
G. W. Low
"I work with electrical equipment for use in the Hazardous Area Industry. It is a well know fact that using a mobile phone while filling up at a petrol station could cause an explosion. It’s not the phone signal but the possible static charge that could build up on the person and then discharge to the car via the pump filler. I have a photo of a Shell burnt out station after such a situation. The people that are writing in should state their experience in the Petrol Chemical Industry before commenting."
Matt Morman (a cell phone technician)
"I had a few things to comment on about the "fact or fiction cell phone myth". There is a industry standard that our Government regulates the electronics used in gas pumps, and anything dealing with explosive chemicals. The reasoning for this is the ESD (Electrostatic discharge). Gas pumps have specialized equipment in them to dissipate the static. As a matter of fact, any equipment involved in the manufacturing, shipping, or selling of chemicals, or petroleum's has to b equipped with the protective circuits. All electronic devices emit ESD, regardless of the power output, However, cell phones are not equipped with this feature. That is why the owners manual for every cell phone carrier warns you not to use it at a gas pump, so they are not liable when someone blows themselves up.