Cellphones Don't Destroy Petrol Stations - Report
Australia's Transport Safety Bureau has published a report that dispels the myths that cellphones can cause explosions at petrol filling stations. There have recently been a number of media reports about the ability of static electricity to ignite fires while motorists have been refuelling at petrol stations. Although the reports have raised awareness among motorists about the hazards of static electricity, they have also led to considerable speculation about the potential for mobile phones to explode. The purpose of this paper was to examine the risks associated with static ignited fires at petrol stations. Specifically, the paper:
- explored the myths and facts about exploding mobile phones and static ignited fires during refuelling;
- examined the findings of studies on static-related fires;
- described the hazards of container fires;
- explored the physical science of static electricity; and
- provided an overview of the chemistry of petrol combustion.
A review of the literature revealed that, between 1993 and 2004, there were 243 reported incidents of fires breaking out at petrol stations around the world. Although the fires were claimed to be caused by exploding mobile phones, experts have subsequently revealed that not one of the incidents was associated with telecommunication equipment. Instead, many of the fires were ignited by the discharge of static electricity from the human body.
Static electricity is a common phenomenon with motor vehicles. The static shock which motorists experience when exiting a car is predominantly caused by friction between the motorist and the seat. The static electricity that has been generated usually discharges when the motorist touches the metal car door on exiting. However, if the first point of contact with metal happens to be the fill point of the fuel dispenser nozzle, the spark can ignite the petrol vapours and cause a brief flash fire. The likelihood of this occurring is higher when the person re-enters their vehicle during refuelling.
In contrast to refuelling a vehicle, the risk of a fire igniting from a static charge is higher when an unearthed container is being filled with fuel. The risk is particularly high when the fuel is spilt or being 'splash filled'. Evidence suggests that refilling containers (either metal or plastic) on the back of a pick-up truck is especially hazardous. This is because the friction between the surfaces of the moving vehicle and the container can build up sufficient energy to cause a spark between the container and the dispenser nozzle, resulting in ignition of the fuel vapours in the air.
You can download the full report from here - http://www.cellular-news.com/white_papers/static_fires.pdf"
Posted to the site on 4th July 2005