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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
They did a thing about this on Mythbusters on Discovery, and were unable to start a fire this way. They pretty much concluded that the static you build up from getting in or our of the car during a fill-up can cause a spark if you touch the car. And doing that near the fueling point can cause a fire. Of course, the worst thing you can do then, which most people do, is pull the hose out of the tank and proceed to spill a LOT of gas into an already burning fire. Not good, especially when you are the one removing the hose. Leave the handle and hose right where it is and get the hell out of there.
And here is a little more data on this urban myth.
WWJD?
JWRTFM!
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
A rather trashy science program in the UK on Sky, called Braniac: Science Abuse performed an experiment where they covered a trailer in gasoline and left a mobile phone in it. They then phoned it. Nothing happened. Then they added more gas and mobile phones, and phoned them all at the same time. Still nothing happened.
Not sure it proved anything, so they blew it up with something anyway. Bit of detail here.
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In the UK they cell phone transmitters on petrol stations.*
Naw... this was Mythbusters episode #1... the exploding toilet.
"I'm not ashamed I can't function in society like I'm supposed to." - Paul Westerberg
Further coverage of this myth here.
Sono koro, bokura wa, sore ga sekai no shinjitsu da to shinjite ita.
With process plants if we got any level of escaped gas etc.. you initate a level 1 shutdown which kills power to everything.
Even the UPS sytem that fed an automated tranmitter, the idea being that the transmitted radio waves could induce current and possibly lead to a spark in any nearby metal.
Petrol isn't quite as flammable, but the same principle applies. If you had you phone near a suitable surface an incoming call may well have the same effect.
Personally i'm more concerned about the mobile phone masts they have installed in petrol station signs.
There are things we know we don't know and things we don't know we don't know. - Donald Rumsfeld
If the oil supply is as low as some sources claim (C 30 years) get used to the idea of catalysed diesel engines and vegetable oil fuel. Safe and Green!
I have yet to see a good energy analysis of biodiesel done that accounts for all the inputs used, e.g. fertilizer, fuel used by harvesting equipment, and energy for processing and transport. It would suprise me if there was a net energy gain, actually it would probably shock me.
Thermodynamics is dismal stuff. Oil works because there are billions of watts just sitting there needing to be scooped up, more or less. Other green technolgies require a lot more processing and it becomes harder to get an energy benefit.
Biodiesel can be used to make other processes more efficient by burning waste, but it in itself does not provide a net energy gain.
..don't panic
This question was also asked by the Myth Busters on the Discovery channel, in episode 2 And their discoveries came to the same conclusions as the PEI, that cell phones do not causes explosions, but that static electricity, especially that built up by entering and exiting the vehical while pumping up, was the cause of many gas station fires.
-- Never monkey with another Monkey's monkey
The real issue is that people get in and out of the car and dont grab ahold of the car, or some other object to ground themselves before grabbing the nozzle. This is when the static electricity gets released and becoems dangerous.
This is also why women are the leading cause to the fires, as they get in and out to do something. None of the fires, according to MythBusters, are started by older people, as older people will grab the car to get out, or stand there the whole time holding the handle to the pump causing them to stay grounded.
between fire and explosion with Gasoline... that might help delineate what we're talking about here.
For a cell-phone held in the hand, we're probably most worried about igniting gasoline vapors, leading to a subsequent fire (unless you're bathing your cell phone in liquid gasoline while talking on it. Nobody's doing that, are they? Please tell me no...)
Gasoline has a flash point about 40-50 degrees below zero, so unless you're in the arctic circle somewhere, gasoline will almost always be producing some vapors. Those vapors can be ignitable and explosive... but only within a certain range of concentration. The range is between the LEL (Lower Explosive Limit) and the UEL (Upper Explosive Limit)... This naturally varies by compound... but for standard gasoline is roughly 1.5% and 7.5%, respectively.
I've never studied it personally, but I'd think the odds of getting just the right concentration around your cell phone (multiple feet from the nozzle) such that it leads to an explosion and fire are extremely small.
Static electricity? Now that's a much more likely culprit... there have been multiple cases where that's happened.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Sorry, you've got it wrong. The gas grill ignitor uses a spring and energy input from the user the smack a peizoelectric crystal, generating enough electricity to create a spark. A peizoelectric speaker is essentially the same thing, only in reverse. Put electricity in, and the crystal vibrates, creating sound. So, I don't beleive that the cell phone buzzer will ignite gasoline vapors. Well, maybe if you removed it from your phone, adjusted it's lead to create a suitable spark gap, and then hit the peizo with a hammer...
It would take some motor to give you ignition there; the motor in a phone vibrator is very small, fully enclosed, and the surfaces are much closer together than the "quench distance" for a gasoline flame. In order to get a flame out, the flame has to find combustible mixture faster than it loses heat via conduction or radiation. All you need to stop a flame is a metal screen, which is how the Davies lamp stops ignition of methane gas.
Time is Nature's way of keeping everything from happening at once... the bitch.
You NEVER get back in a car when fueling. This lady suffered because of it. You are safe when fueling as long as you never open/close the car doors and more so if you don;t get in and out. It's tha static that causes this. Same thing goes when filling a can of gas for your lawn mower. Putting it in your car when filling not only puts you at risk for the gas overflowing, but also for the static to buiild up.
:) According to Nokia anyway.
Cell Phones, PDAS and everything else do not even come close to causing a gas station fire...unless your using a non manufacturer batter with explosion problems!
Gorkman
Much later on, in the 1960s IIRC, a manager at Ford in the UK had some petrol (gasoline to all you US /.ers) poured into pools in the concrete-surfaced yard, then a tractor dragged assorted pieces of scrap iron through it for several hours, no ignition! It was concluded that most car fires following accidents are as a result of sparks from damaged wiring, not friction. However, some believe that repeating the Ford experiment with modern unleaded fuel might give entirely different results, as apparently it does ignite more easily, so is more at risk from friction sparks, or RF sparks from mobiles.
I have actually seen someone smoking while filling a lawn mower from a can. I wonder how many times he got away with it before disaster struck. Never seen it at a filling station though.
Of course, it's up to you whether you choose to accept this study.
All aircraft refueling pumps require, by law, a grounding wire to be connected to the aircraft to reduce the opportunity for static electric discharge before even putting the pump nozzle into the tank opening. Aircraft refueling involves a *much* higher rate of flow than auto refueling too (I can fill the twin 25 gallon tanks in my airplane in a mere fraction of the time it takes to put 20 gallons into my car). The high rate of flow of a non-polar fluid from the nozzle into the tank forms a sort of Van DeGraff generator. Auto refueling pumps are supposed to have a conductor built into the hose to ground the vehivle to the nozzle as you put it into the vehicle, but maybe there should also be a separate ground wire to connect to the vehicle *before* putting the nozzle in.
I can't believe the parent is a +5 ... perhaps the moderators just saw a long post and figured it must be worth +5, without even reading the content first.
.. .there wouldn't be any current... voltage by itself is pretty worthless without current to make something happen. BUT... if you happened to induce a small voltage on the pump handle (1 milliwatt - I'm being generous) with your little cell phone, wheres the current going to flow? That's right, nowhere ... there's no complete circuit. In fact, you're likely to get more RF energy out of your car when the engine is running than when you're on your cell phone.
... which will magnify the actual voltage to the level where a spark will occur.
... 9/10 times when I go to shut the door, I expect to get a static shock. Happens so often that I'm now very careful at the pump. Discharge on your car, before you accidentally/unknowingly discharge into the pump.
First of all, there would be little (if any) voltage induced on the pump handle. BUT
"Under certain conditions of dimensions and position there are resonances at some of the cellular frequencies..."
No.
No. Resonance does not "magnify" voltage. Here's a quick definition of resonance for you... "Condition in a circuit when, for an applied alternating voltage of a given frequency, the inductive and capacitive reactances are equal."
Ok, so you might be thinking, "well, antennas resonate and that's how we receive radio waves". Well bucko, an antenna resonates because it's part of a circuit containing inductors and capictors which make it resonate at the desired frequency. The current created through the inductors still needs to be amplified many times before it's strong enough to drive a speaker! AND, even then, it's probably still not enough current to create a spark!
A gas pump handle has few qualities of inductance. Obviously, it's not going to resonate without some type of inductor... and last time I checked, there's nothing remotely close to an inductor in a gas pump handle.
Discovery channel has already done a great job of killing this myth. Fires at the pump are caused by static discharge. Period. When a driver gets out of the car, they create a shit load (pun) of static potential when their ass slides across the car seat. This is less likely to happen with old people because they almost always need to grab the car to assist their exit, thus grounding the static charge.
But, for us "young" people, it's common to get out of the car without ever grounding. Happens to me all the time
Static discharge will create an open spark!! What more do you need for ignition?? Fuel, spark, oxygen. Fire. Resonance? Sorry bucko, doesn't work.
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People keep saying that women cause most of these fires because they are more prone to getting back into the vehicle. That little factoid comes from a well-known urban legend; no statistics exist to back it up. Check out the urban legend site at snopes.com.
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
Here in the U.S. there is a show on The Discovery Channel that is called Myth Busters. A pretty cool show too. In any evemt, they did a show on just this topic - Check Episode 2. They proved it to be a Myth
In the April 2004 IEEE Spectrum, page 6 (no link available, sorry) there's a statement approved by the IEEE Engineering in Medicine and Biology's Committee on Man and Radiation.
Basically it does a great analysis of the physics involved in creating a spark to ignite gasoline vapors and concludes there is nothing to worry about.
They also clarify the difference between (dangerous) static sparks and the potential hazard from cell phones.
The rumored risk from cell phones seems to me a lot like the rumored risk to commercial aircraft avionics from laptops/electronics/etc. Every time there is an unexplained incident, the people in charge (fire chiefs, pilots, whatever) jump to blame whatever nearby technology they don't fully understand. Anecdotal evidence does not constitute proof, however. Too bad the mainstream media doesn't do a little more homework.
The funny part is that it took longer you to write that post full of lies than to actually lookup the truth that biodiesel is energy positive.
Biodiesel : domestic, renewable, clean, and in the fuel tank of my bone stock 2002 New Beetle TDI
They reran it at 7PM last night, and will be playing it again tonight at 2AM, set your Tivo!
MythBusters Show Schedule
Remember Lexington Green!
They tried to reproduce this on Mythbusters and found it was nearly impossible to create a ball of fire this way.
They had to enclose the test area and get the perfect mixture of air and gasolinve vapors, and even go as far as putting an ignitor on the cell phone.
I would have posted this sooner, but I've spent the morning at a large chemical plant (polyester resins and intermediates) doing fire extinguisher maintenance. When I'm out there, my cell phone stays in my car. Why? Because it's not intrinsically safe. No equipment that doesn't bear that designation is allowed anywhere near the process areas. The risk of microscopic internal spark/arc is there with any battery operated device, be it a cell phone, a flashlight, or an iPod. Check out the heavy duty flashlights used in industrial settings; they're rated Intrinsically Safe by MSHA (Mine Safety and Health Association).
So the short answer is, forget all this crap about which thingamjig resonates at 1.21 gigawatts; it's a simple fact that any electrically powered device can ignite flammable vapors unless specially designed not to, which is often by way of inner and outer layers of air tight casing.
Also, there's little doubt that common fabric-induced static is responsible for most gas pump fires. But to assume that proves that cell phones can't also ignite flammable vapors is silly.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Are the real cause of the problem.
Before the use of plastic became prevalent in cars, the gas tanks were made of metal - from the tank all the way up to the fill pipe. Nowadays, the filler pipe is rarely made of metal - it's usually plastic or rubber.
Herein lies the problem: A metal filler pipe will ground the vehicle when the pump is placed in the opening; plastic won't. Normally, any static electicity buildup created by entering/exiting the vehicle would have been prevented by the pump grounding the vehicle. But with plastic filler pipes, the pump no longer grounds the vehicle, and hence, a static charge can build up on the vehicle as it is fueled.
Incidentally, ever time I leave my vehicle in cold, dry weather, I experience a rather substantial shock as I close the door - the friction with the seat builds up static electricity. I've often wondered what would happen if I left the door open (thus remaining staticly charged) and attempted to pump gas....
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I think it is definitely NOT a Doppler effect issue. I have been traveling a lot on French High-Speed Trains ( TGV ) and using my cell phone on it. TGVs run as fast as 330 km/h i.e. about 183 mph, and cell phones work fine BUT you frequently lose contact, as
1) there are so many tunnels
2) you move from cell to cell so quickly.
Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
However, as regards the battery theory, if you directly short a charged mobile battery, some types will catch fire or explode after a short while, within themselves, and yes you can produce sparks sufficient to ignite petrol from a small battery, again by means of an intermittent connection, DC is just as effective as RF.
my gas is cheaper, i never have to leave the car
And without paying for the make-work jobs, the gas would be cheaper still. Basic economics, but I'm always surprised at how many NJ residents are convinced it's a wonderful system.
How to solve most of our problems: 1.Lots of nuclear plants. 2.Cure aging.