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Can Cell Phones Ignite Gasoline Vapors?
Iphtashu Fitz writes "Matthew Erhorn was filling his car with gasoline outside of New Paltz, NY when when he flipped open his cell phone to answer a call. The next thing he knew he was engulfed by a ball of fire. Luckily for Erhorn a quick thinking employee hit the emergency fire suppression system and he ended up with only minor burns. Firefighters investigating the accident concluded that the cell phone triggered the fire. Experts at The Petroluum Equipment Institute disagree however, attributing the fire to static electricity. Since 1992 the PEI has documented 158 cases of gas pump fires believed to have been started by static electricity. Apparently cell phone signals are too weak to ignite gasoline vapors, but the human body can generate enough static electiricy (60,000 volts) from simply sliding out of your car seat to do just that. Do you pay attention to all those signs at the gas pump telling you to to make sure your car, cell phone, PDA, pacemaker, etc. are all turned off before you start pumping?"
The stats also show that women are "the cause" of more fires at the gas pump. Hey, don't blame me... it's just the stats, ma'am!
The Mythbusters took care of this MYTH in episode #2:
Episode 2: Cell Phone Destruction, Silicone Breasts, CD-ROM Shattering
In this episode, Jamie and Adam test several explosive theories. Can chatting on a cell phone while pumping gas cause the pump to blow up? Our mythbusters put themselves at risk so you don't have to. They also put silicone breast implants to the test at high altitude. Will they burst under pressure? Finally, we'll learn once and for all if high-speed CD-ROM players can really shatter a compact disc.
"I'm not ashamed I can't function in society like I'm supposed to." - Paul Westerberg
You are not telling the story in hope that people follow the link.
Here it goes, short version: they tried, they tried hard, to make a cell phone ignite gasoline vapours... and they failed miserably. They put the stuff in a closed environment, tested many concentrations of gas vapour, nothing worked.
The only way this happens is static electicity near the fuel entrance
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
In the UK they cell phone transmitters on petrol stations.*
> Can cellphones really disrupt your average PC in as much as they might ignite petrol fumes...
No, but they can put everybody else within earshot off their work, and into a slow state of boiling rage...
Listening to three other people's incessant mindless babbling over their mobiles for a few hours is a good way to get nothing done, and really angry about it...
I'm guessing their reasoning for banning your mobile is just common courtesy...
Turn off you PACEMAKER? What?
They did manage to get a very nice explosion by leading a wire to the cravan and getting soomeone wearing nylon clothes and standing on a bucket to touch the other end, though.
PS. They really liked blowing up caravans...
if your cellphone is only inches from your farts i would suggest you are holding it wrong
They're flammable and they originate mere inches from our cell phones.
There you go talking out of your ass again.
No! Incorrect assumptions like that are exactly why these fires and explosions keep occurring worldwide. The battery could obviously cause a fire, all but the very smallest batteries can, but the primary hazard is sparks caused by the RF voltage induced in the pump nozzle. Under certain conditions of dimensions and position there are resonances at some of the cellular frequencies, which will magnify the actual voltage to the level where a spark will occur.
You are suggesting it's RF resonance causing the explosion as opposed to a spark from the phone igniting the vapours or any static discharge? Please point us to a single piece of evidence.
It amazes me how in the UK, where warning notices are to be seen quite often in filling stations, that imbeciles continue their pathetic and unnecessary conversations while filling. If I see one near me, I move, and quickly...... It is a criminal offence under the petroleum spirit regulations, it is time that it was enforced properly.
I personally don't believe there is a risk, I'm with the static theory.
BTW most HF/VHF/UHF communications equipment is potentially lethal in these circumstances. I know that cellular base stations are sometimes sited on the premises, they are carefully positioned, and the inverse square law ensures that the signal level at the pumps is well below the safety limit.
We all know about the inverse square law, and it's enough to take a mobile phone power down to a level not to affect the brain a few millimeters away let alone a whacking great conductor (with no pointy bits) a few feet away. I refer you to my answer to paragraph one.
It is sad that the general public are so ignorant and ill-informed as to constantly put other people's lifes at risk by this stupid behaviour. In the UK the law requires you to switch off before entering the filling station, off means off, not standby, because if the mobile needs to access the network or respond to an incoming call, its first and unpredictable transmission will be at full power!
That's not what I've read on the GSM protocol. I've read it latches on to the lower power signal to conserve battery.
Don't get me started on where else they are lethal such as on aircraft, at least one businessman is, very properly, in jail in the UK as a result of his wilful ignorance on that score. If I were the judge, I would have made it a life sentence, because he put so many lives at risk, even when told not to. If stiff sentences were handed out for using mobiles in filling stations, the practice would diminish substantially. It would not stop entirely, there is always some idiot who knows better than the safety legislators.
What an irrelevant arguement. This law is about potentially disrupting computer systems on a craft, not about making them explode. And in fact the maximum risk is when the craft is on the ground and not in the air.
Phillip.
Property for sale in Nice, France
is the voltage on the antenna really enormous?
Absolutely.
An antenna is a transmission line terminated with an open circuit. (This IS a striaght-line - or bent in various ways - transformer.) The voltage at the end is quite high. If it's excited at its resonance, it is limited only by the losses from radiation, resistance, and surrounding materials.
Consider the "firefly" decorations once popular on CB antennas. 4.5 watts into 52 ohms produces 15 1/4 volts. A neon lamp requires about 90 volts to ionize and I think it's about 45 to sustain. Yet put one on the end of the antenna and it lights up merrily when you key the transmitter. No big illegal power amplifier required.
Repeat after me: 3 volts do not arc.
Sure it does, under a number of conditions.
You're thinking of STARTING an arc in air. For three volts the gap would have to be microscopic.
But when breaking a circuit with current flowing through it you end up with exactly that microscopic gap initially. Once the air is ionized the arc can be sustained by a very low voltage. And with any inductance in the circuit at all (even the stray inductance from the wiring) the voltage will climb to maintain the arc until the current through the inductor is finally brought to a halt by the reverse voltage. So the arc can be "pulled out" to significant lengths.
This is EXACTLY the mechanism that produces the voltage spike in the primary (and thus also in the secondary) of the transformer in a contact-point type auto ignition.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way