"Please turn off cellular phone while pumping gas"

I saw this warning at the pump today, at the Sinclair station. What the heck does a cellular phone have to do with pumping gas? I mean, extinguish smoking materials, that’s pretty obvious. But cell phones?? I considered that they just didn’t want “distracted pumping”, but then I can’t figure out any reason for the station to be afraid of distracted pumping, so that doesn’t work.

Earlier threads on this subject:

http://boards.straightdope.com/sdmb/showthread.php?threadid=111667
http://boards.straightdope.com/sdmb/showthread.php?threadid=129845
http://boards.straightdope.com/sdmb/showthread.php?threadid=15933
http://boards.straightdope.com/sdmb/showthread.php?threadid=6367

Snopes calls BS.

I actually answered my cell phone yesterday while I was pumping gas, and I’m still here. I didn’t even think about it until I was already back on the road.

In the UK Shell are actually installing cell-phone base transmitters in some of their filling stations with the anntennas hidden in the " Shell " sign. These base stations are much more powerful than the actual cell phone . So if it is safe enough for the base station then it must be safe enough for the cell phone.

Data point: the PR Fire Department just made it subject to a $500 fine to use the cell phone at the pump or allow it to be used (i.e. both you and the gas station get fined). The best explanation the Fire Chief provided was the reference to the alleged Indonesia/Malaysia/wherever incident and a “just to be safe” attitude.

And they wonder why there’s no respect for public servants.

Snopes link above didn’t work for me. Try this: http://www.snopes.com/autos/hazards/gasvapor.asp

I’ve heard plenty of warnings that skin burns can occur if contact is made with a damaged antenna; if that’s true (and I’m not sure), then could a damaged antenna also create conditions that could ignite flammable vapours (say if it touched something that was earthed)?

I don’t believe this aspect would apply to cell phones. The ones I’ve seen don’t have any exposed metal antennas.

(I remember one that had a “pull-out antenna” that was actually a dummy to give the user a feeling of accomplishing something–the actual atenna was a fixed piece inside the phone, totally separate from the pull-out.)

There is just not enough RF energy from a cell-phone to produce a burn. I think there would be more energy produced from a static spark from the metelwork ofyour car then from a cell-phone. The only other source of energy from the cell-phone is from the battery. there again, not enough energy especially compared to that from your spark plugs from your car when you drive into the filling station.

Gas station monkey here.

We have rules against cell phone usage, but no one enforces them (except for the most anal people). The issue is supposed to be that when cell phones are in use - especially when they suddenly power up and activate, as in when a call comes in - there can be a small electrostatic discharge which could potentially detonate gas fumes.

One of my coworkers was an electrician in the army, though, and he said for practical purposes you’d need to have absolutely no humidity and a freak set of circumstances for anything like that to happen.

I think any alleged static discharge generated by the internal electronics of the phone would damage the phone itself, what will all the ESD sensitive components on it. At worst there might be an EM field generated by a small motor that is used to vibrate the phone, but certainly no exposed arc.

This is crazy!

Here in the north of England, nearly every petrol (gas) station I see has “No mobile (cell) phones” signs up. They sure as hell aren’t happy with you using a phone in the stations.

I trust snopes…but now I’m torn - what is the deal then?

From what I’ve heard, they’re worried about the risks of fire. It’s nothing to do with the electrostatic discharge or anything, but to do with the battery. Think about the last time you dropped your phone, almost certainly, the battery came out since they’re not held in totally securely. When this happens, there’s gonna be a spark and in a petrol station this could mean kaboom.

At least that’s what I’d heard, I dont really think the RF frequency or anything because as Rayne Man said, here in the UK there are enormous transmitters in the petrol stations themselves.

I dont think the RF frequency has anything to do with it

I’m sure that’s what I wrote damnit

I work for a cell phone company and we got a statement about this. It is BS (written more politely of course for our offical statement). Lets see…

Copy and paste doesn’t work here’s the message we have:

*The reported incidents are all urban myths; not one has been verified to be true.

The ability of wireless phones to generate sufficient energy in the form of electromagnetic waves to create a spark is considered extremely remote. For example, a British Standard BS 6656 suggests that the power level would have to be at least 8 watts to be hazardous under the worst case conditions. Hand held wireless phones operate at power levels under 0.6 watts. *

This is our public response to the whole issue.

Read More Here on this Debate
From an engineering aspect, I’d like to point out that any area has a Hazardous Area Classification (NFPA, NEC, etc. ) codes. All electronics/electricals need to conform to this code. All the electrical and electronic stuff you see around a gas station are indeed made to conform to this code - but your cell phone is not.

I don’t know what the Insurance/Legal issue here will be. But if a gas station did went up in flames and the Insurance company could find any evidence of any device (cell phone) that did’nt confirm to the NFPA code being in the vicinity the Gas Station Owner may have to pick up the bill.

So, I guess the Gas Stations are just covering their ass by posting that warning.

Forgot to add CSA does require Intrinsically Safe Wireless system to operate in hazardous locations. Motorola does market these devices for petroleum plants/ etc. They are also sometimes known as explosion proof.

…with a few notable exceptions: the cars pulling up to the pumps.

The real issue would seem to be, what could be so different about cell phone electronics than about the electronics in the average automobile?

Certainly the cell phone is a moderately powerful RF transmitter, but that’s not an obvious source of fire hazard. (Does anyone know if similar restrictions were ever imposed on vehicles with CB radios and other transmitters?)

If I single freak spark could blow up a gas station I would think having a car with old spark plug wires would spell certain death. If you look under the hood of a car at night with old plug wires you can see sparks arcing from the wires to the engine block and exhast manifold. These sparks would be much stronger than anything a cellphone could generate. A typical car ignition system produces 12000-50000 volts.

/Markus