Mis-Cat - I think you're right, cos according to the reference in my last comment Mythbusters tried to cause an ignitinion with a mobile but were unable to;

"According to some experts there is a danger that using a mobile phone near gas pumps could touch off an explosion, but not only have we found no real-life instances of such an explosion occurring, we don't know anyone who has demonstrated experimentally that it's even possible (including the folks at The Discovery Channel's Mythbusters program)."

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