I found these Q & A's at the Petroleum Equiptment Institute website.
Q: Cell Phones
Are cell phones unsafe?
A: PEI has not been able to document any cases of cellular phones causing a fire at a gas station. However, we do not recommend using any device that might cause distractions while refueling.
Our refueling fire report has nothing to do with cell phones whatsoever, but we have posted links to information regarding this urban legend under Related Info.
PEI has not documented a single refueling fire caused by a cell phone or pager.
Q: Engine Running
Why is it dangerous to leave your car running?
A: Many people believe this safety warning only applies to older cars. That is not true. A running car presents a number of "ignition sources" for fuel vapor. The exhaust components of a modern car can literally glow red hot during normal operation. The typical ignition system creates voltages above 40,000 volts.
But turning off your engine while refueling isn't just to prevent your car from starting a fire. There is also a safety issue in the event of fire, regardless of the source. In case a fire does occur in a gas station a running car is a danger. Imagine that fire burns through one of the rubber fuel hoses under your running car. Most fuel pumps deliver gasoline at about 15 to 40 pounds per square inch (PSI). Your fuel pump is now spraying a tremendous amount of gasoline at an open flame.
Q: Footwear
Are rubber-soled shoes safer?
A: No. Rubber soles insulate the wearer which makes it more difficult to discharge static buildup to the ground.
Q: Fuels and Static
Does this only apply to gasoline?
A: Not necessarily. The only incidents we have documented involve gasoline. Compressed natural gas refueling does not normally involve any concentrated vapors so that would also be an unlikely event. The higher flash point of diesel makes such an occurrence unlikely but not impossible, especially in hot weather.
Q: Gas Cans
Are plastic gas cans safe?
A: Yes, but they should always be placed on the ground when filling. Never fill any portable container (regardless of material) while it is inside your car or pickup bed.
Q: In Case of Fire
What should I do if there is a fire?
A: If a fire does occur, don't panic. Do not remove the nozzle from the gas tank. Back away from the car and immediately tell the station attendant so they can operate the emergency shut-off and a fire extinguisher.
Q: Just Cars?
Can this happen to motorcycles, ATVs, snowmobiles, etc.?
A: Probably not. We have not documented any incidents involving motorcycles and static-related ignition. However, it is wise to keep the nozzle in contact with the fuel filler neck during the refueling process. Especially on recreational vehicles equipped with plastic fuel tanks.
Q: Nozzle Latches
Why not remove the hold-open latches?
A: Some states and countries do not allow the automatic nozzle latch that clicks off when your tank is full. This is intended to eliminate unattended refueling.
Unfortunately, accidents occur when consumers attempt to fabricate their own makeshift latches. Placing an object, such as a gas cap, under the nozzle lever can make the cure more dangerous than the symptom. The most severe case was the victim who jammed the nozzle open with his disposable lighter.
Q: Passengers
Is it safe for passengers to stay in the car?
A: That's probably the safest place for passengers to be. The person refuleing should not get back in the car because they might build up a dangerous static electrical charge.
In the event passengers do get out of the car to operate the pump we recommend they touch a metal portion of your car or the dispenser before touching the nozzle.
Q: Pump Grounding
Why not just ground the pump/hose/nozzle?
A: They already are. Or, at least, they should be. Standards call for continuity between the dispenser and refueling nozzle.
The issue here is the electrical difference of potential between the person and their vehicle. They have created a static charge between their body and their car, which may not be discharged by touching another grounded object.
Q: Reentering Vehicle
Why can't I get back in my car?
A: Don't get back in while you're gassing up. This can create a static buildup that will cause a spark when you touch the gas pump. Most of the incidents we have investigated involved the driver starting the pump, getting back into their car, and when the driver gets back out of the car to remove the nozzle, static is generated when they slide across the seat and a spark may occur when they reach for the nozzle.
This does not apply to full-service or passengers in your vehicle so long as they are not near the refueling nozzle.
Q: Rubber Boots
Are dispensers equipped with vapor recovery systems also affected?
A: Some metropolitan areas mandate the use of evaporative vapor recovery equipment. This is most commonly identified by a large rubber boot attached to the gas pump nozzle.
Our findings indicate that vapor recovery systems with such a device greatly reduce the risk of static-related ignition.
Q: Static Buildup
Why does my car shock me?
A: Most static buildup is due to movement between yourself and the car seat. Your car also builds up static electricity as it moves through the air. There is also evidence the materials used in high mileage tires contribute to the problem.
Q: Static Materials
Am I safe because I am wearing gloves or have leather upholstery?
A: No. Certain materials can reduce the the buildup and/or disperse the discharge of static electricity. But they do not eliminate it entirely.
Q: Static Discharge Wires
Why not install static wires on gas pumps like airplanes use?
A: Aircraft use static grounding wires before fueling because of the immense amount of static generated during flight. Most of the automotive refueling accidents we have investigated occurred after the refueling process.
Dispenser nozzles and hose are made so they ground through the dispenser. In other words, they have the grounding wire built in. In most cases a properly operating nozzle inserted into a metal fuel filler neck serves the same purpose of electrically connecting the vehicle to ground through the dispenser. Just as the grounding wire on aircraft does.
Q: Warning Labels
Why aren't there any warning labels on the pump?
A: Regulations and labeling requirements are usually the jurisdiction of local fire authorities. To learn more about these regulations you should contact your local fire marshall.