Originally Posted by
Nickolash27
There is some risk at a service station, for example if a phone was dropped and caused a spark, as petroleum vapours sink to floor level. However it's a very low risk. So not a myth but an extremely cautious approach being taken.
Many other objects such as keys, flint etc. could equally cause such ignition, however they are not banned.
That however, is not the official reason provided by service stations. Upon enquiry, I found the rule is based upon the belief electromagnetic radiation emitted from cellphones can cause sparks and hence ignition to fuel vapours. Mythbusters tested this and found it to be false, as have many scientific studies. The energy emitted by cellphones (~1 watt/cm2) is far too low to cause any spark.