[saket77]

This fire by mobile phone is surely an urban legend. If the mobile switch activation spark can burn down fuel pumps, then there are uncountable parts in your car which produce sparks. Like the ignition switch, starter motor brushes, alternator brushes and may be even the turning the radio on/off!

[Kumar R]

Good observation. Now that I think of it, both pumps where I refuel have two credit card machines barely 1-2 feet away from the fuel dispenser. One is a wireless swipe machine which is sometimes brought within inches of the fuel nozzle. In addition both have ATMs located 12 feet from the nozzles (when motorist is outside vehicle and punching in PIN for validation). One has a small department store where people use phone without restriction. Not to mention this is a residential neighbourhood and it is certain that residents about 20 feet on either side of the fuel dispensers would be using mobiles, wifi, satellite TV, etc.

Whoever has thought out the ban has obviously not kept pace with these developments.

It would be helpful if some technically qualified member would shed some light on this risk and whether the card reader / mobile analogy makes sense.

[Jeroen]

Originally Posted by Kumar R

Good observation. Now that I think of it, both pumps where I refuel have two credit card machines barely 1-2 feet away from the fuel dispenser. One is a wireless swipe machine which is sometimes brought within inches of the fuel nozzle. In addition both have ATMs located 12 feet from the nozzles (when motorist is outside vehicle and punching in PIN for validation). One has a small department store where people use phone without restriction. Not to mention this is a residential neighbourhood and it is certain that residents about 20 feet on either side of the fuel dispensers would be using mobiles, wifi, satellite TV, etc.

Whoever has thought out the ban has obviously not kept pace with these developments.

It would be helpful if some technically qualified member would shed some light on this risk and whether the card reader / mobile analogy makes sense.

Fire and explosion hazard has absolutely nothing to do with devices that transmit or receive radio signals as such. Whether its a WiFi, mobile network, satellite, GPS whatever signal. Radio signals do not cause a fire to start. See my earlier post, you need something that can reach a certain temperature and or spark with sufficient power to start a fire in a petrol gas filled environment. I would say in the environment of your typical Indian petrol station the biggest reason for concern would be people smoking (and I see that regularly) and loose electrical wires hanging down from various buildings and fixture. If they are carrying 220VAC and start sparking and there are some petrol fumes in the air, you will see an explosion.

You could cram 500 people around one petrol pump and have them all make a mobile call while you are putting petrol in a car and nothing will happen.

Jeroen

[iamendangered]

As rightly pointed out, static electricity is the real culprit here.

Please watch the link below, its a video that Mythbusters did to find out about this exact topic, and explains it better than I can with words

https://www.youtube.com/watch?v=uw6-PhvcS3M

[Jeroen]

Nice video. I'm a big fan of the Myth Busters. Read somewhere that next season they are going back to basic and it will be back to just the two of them.

Just to add a bit more on static electricity and the inherent dangers when discharging. I started my career in the navy and offshore and as part of our training we also received extensive fire fighting training. Part of fire fighting is to understand what causes fires and explosions in the first place.

The oil industry, both on- as well as off-shore had seen many explosions without any evidence of sparking or high temperature. So in the late 60s, early 70s a lot of research was poured into building a better understanding on what blew up all those storage tanks.

What they found is that it was static discharge. Simply put, anywhere where you have friction between two different surfaces, there is a likelihood of static electricity building up. If the friction continues long enough, ultimately there will be a discharge and a seemingly spontaneous explosion. How much static electricity builts up is of course dependent on many factors, the material involved being an important one. But on refineries, train loading stations and on oil rigs, fuels are typically pumped through essentially rubber hoses. The fuel has a certain friction inside the hose and thus electric charge builts up and at some point in time a discharge happens and blows up the tank.

I remember very vividly one of the films they showed about an experiment. They were just pumping fuel from one tank to the other through a rubber hose. At some point in time the tank blew up, apparently spontaneously, but it was the static discharge. They measured the charge and you could see it increasing as they pumped longer and it would increase faster if they pumped more volume as well.

This very same phenomena is present around dry bulk pumping as well. E.g. grain, cement and such. You might have heard about grain silo explosions? Exactly the same thing, static electricity building up and discharging.

So this is the reason that airplanes always get grounded before they start fueling them. Fueling a plane take quite a bit of time, rubber hoses involved!

When I worked on supply and anchor handling vessels we also carried fuel, cement and other dry bulk good for the oil rigs. We would maneuver under the oil rig, a huge hose was put down, we would connect to our discharge station and we would pump the fuel and or dry bulk up onto the rig. I've never heard of accidents out on sea, but there have been several accidents in harbors during the loading of the bulk tanks of Supply Vessels.

Especially when you have an inland water way with fresh water, there is poor grounding for the ship. One of my colleagues touched a hose, through which we were taking on dry bulk goods. We'd been at it for well over an hour or so.

The hose was highly charged and he nearly got electrocuted. Left him with some permanent disabilities. So even supply vessels these days get grounded before commencing pumping\loading operations.

On your car you don't need to worry about the above scenario. Filling up your tank is done quickly, small volumes and there is not enough time to built sufficient charge to matter. But your car does built up charge as you drive along. Its the friction of the air molecules agains the chassis. And it can and will give you a nasty shock as I explained in earlier post.

Jeroen

[bullrun87]

Originally Posted by tsk1979

Mobile phones have no hazard. Its an urban legend. Often, laws are made by people with zilch scientific knowledge(eg calls for WIFI ban)

The problem is static electricity.

.

Yes I agree static electricity is the main issue and just about anything (a rock, your sweater) could cause a fire with sufficient charge buildup. Most of the videos floating around on youtube claiming the fire was caused by a cellphone cant be substantiated. But the oil and gas industry still considers cellphone use in hazardous/vapor rich areas to be unsafe. These cellphones we use are not certified to be used in hydrocarbon rich atmospheres that may temporarily exist around say a refuelling nozzle . There are intrinsically safe phones available in which batteries/internals are shielded from the atmosphere. These phones are certified and can be used safely in any conditions.People working in the oil and gas industry are only allowed to use certified "intrinsically safe" equipment. But I would still say cellphones pose a negligible ignition risk and static electricity would be far more likely to cause a hydrocarbon fire at a fuelling station than your cellphone. Talking on phones is not the problem, the problem is that most have removable batteries, removing/ inserting batteries may cause a spark although its highly unikely.

[chaudh2s]

Originally Posted by joybhowmik

Static charge build up is common. Some drivers loop a chain of sufficient length through a hole in the chassis and let it dangle on the ground. Presumably this is for discharging their car of static electricity.

Hey now i understand why all the DTC low floor CNG buses (Tata marcopolo & AL) have this chain hanging at the back, with a triangular plate that touches the ground. I wasn't able to figure it out all these years the purpose of that chain until i saw this post of yours. Thanks!

[stanjohn123]

Our fuels are so adulterated they wouldn't catch fire even with a match stick, let alone cell phones

[calypsoGT]

Originally Posted by Hrishi_111

Following video has been viral on social networks for quite some time. Even though it is not very clear in the video whether the actual cell phone caused the fire, it certainly describes the level of precautions to be taken and consequences if they are ignored:

Why does it seem like some part of the footage is missing right before the petrol catches on fire?

Mod Note: Please quote ONLY the relevant bits of a post. Quoting a full, long post inconveniences our mobile readers.

[anshuman_v]

There are other interesting trends at petrol stations:

- Why are bikers asked to get down from the bike and only then fill the petrol? Would they run away after filling - or just by sitting on the bike, do they create a fire hazard?

- Some petrol pumps allow you to take petrol in a jar/jerrycan; while some dont.

Not all of it is always rational, one would think - some safety, some for tradition.

[gopa99]

Originally Posted by latentpotential

I have always seen every attendant at every petrol pump, be it big or small, curse you when you try to use your phone at their pump.
the world covering this topic.

As an ex refinery guy, i can say this: The whole genesis of curbs on electronic equipment is with regards to the LEL, which is the Lower Explosive Limit, which for gasoline I guess is in the range of 1.3% (wt concentration).

In confined spaces or in cases of heavy filling rates (tanker loading /discharge at refineries), the vapor concentration looms very close to the LEL. in such cases we have norms on intrinsically safe devices and machinery and flame proof fittings for electrical units.
But in gas dispensing stations, the space is well ventilated and this risk of reaching any fad near LEL is avoided.

On the card machines using wifi, I guess the oil industry is always a fad behind in moving with new technology. I am sure new rules could come into effect for them too once they recognize this as a risk element as was identified for the cell phone a decade back.

[latentpotential]

Originally Posted by gopa99

As an ex refinery guy, i can say this: The whole genesis of curbs on electronic equipment is with regards to the LEL, which is the Lower Explosive Limit, which for gasoline I guess is in the range of 1.3% (wt concentration).

In confined spaces or in cases of heavy filling rates (tanker loading /discharge at refineries), the vapor concentration looms very close to the LEL. in such cases we have norms on intrinsically safe devices and machinery and flame proof fittings for electrical units.
But in gas dispensing stations, the space is well ventilated and this risk of reaching any fad near LEL is avoided.

On the card machines using wifi, I guess the oil industry is always a fad behind in moving with new technology. I am sure new rules could come into effect for them too once they recognize this as a risk element as was identified for the cell phone a decade back.

I am talking to my clients in Oil & Gas industry, they are yet to come back to me with a definitive answer. My understanding is they will have to do some testing (probably some industry experts) and figure out the risk profile of such devices.

[Samurai]

In my initial years in New Jersey, I used to dread winters for one specific reason, static electricity. I used to get static electricity shock from water taps, house door handle and car door handle. It was so regular, my hand always used to stop an inch away from the tap/door, and gingerly touch to discharge it before using. Sometimes when I stop my finger an inch away, I would see a spark fly between my finger and the tap/door handle. It was freaky. Fortunately I rarely had to fill gas on my own since customers are not allowed to pump gas at NJ gas stations. I wonder what would have happened if I had struck a spark there.

After two years of that, I returned to Bangalore. It took me another year to get over my one-inch stopping habit before touching a tap or door handle.

[atul.sxna]

interesting...very interesting.

I have seen these same petrol station guys speaking on their mobiles to their GARLFRANDS often at noon when the rush is relatively low and they have nothing else to do.