Petrol Station Explosions?

Good point, I never turn mine off either, and I never heard of one exploding either.

wikipedia:

Although urban legends persist that a mobile phone can cause sparks or a build-up of static electricity in the user, this has not been duplicated under any controlled condition. Nevertheless, super-cautious mobile phone manufacturers and gas stations ask users to switch off their phones. One suggested origin of this myth is that the scare was started by gas station companies themselves because with some older model fuel pumps the cell phone signal would interfere with the fuel counter causing it to give a lower reading, and thus users could get some gas for free. A spark from wearing nylon clothing is more likely than from a mobile phone, to say nothing of the sparks that can occur in faulty car wiring or troubled starting and ignition systems. Most fueling is done in the open air, and there is not often an explosive concentration of vapors present.

much more likely is an explosion from static electricity:

wikipedia again:

Automobiles can build up static charges by driving on dry pavements. A driver who does not discharge static by contacting a conductive part of the automobile will carry it to the insulated handle of the nozzle and the static potential will eventually be discharged when this purposely grounded arrangement is put into contact with the metallic filler neck of the vehicle. Ordinarily, vapor concentrations in the area of this filling operation are below the lower explosive limit of the product being dispensed, so the static discharge causes no problem. The Petroleum Equipment Institute has recorded incidents of static-related ignition at refueling sites since early 2000.

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Think the theory is related to why you don't (normally) put metal inside a microwave oven , because that WILL result in sparks.

Following is the best I can do as to why radio waves can sometimes cause sparks...

http://www.madsci.org/posts/archives/dec97/8829095...

But, like it seems everyone else, I've not heard of mobiles causing ACTUAL sparking on metal surfaces. Could be because the radio emissions from a mobile phone are considerably less than that inside a microwave, maybe it's because the frequencies are different.. Older mobiles/car phones were more powerful so maybe they could do it. Not sure about CB radios (Couple of watts output?)

The risk of an explosion is very low, especially with a modern mobile phone. It was higher with the old "talking brick" mobiles and built-in carphones, though.

However, the warnings are still in place, mainly to cover the petrol companies in this litigation-crazed world and probably also to try and stop candidates for the "Darwin Awards" using their mobiles whilst filling up - after all they still insist on using them whilst driving!

relies upon on numerous factors. specifically, the quantity of gas on the station on the time of the ignition. Flames can go a lot farther than that if the realm is dry adequate or has a severe wildfire chance. maximum fires double in length each and every 3 minutes, assuming a reliable gas source.

For those who are interested, I believe Myth Busters did a segment on this for one of their shows. They couldn't get an explosion.