Is Smoking While Pumping Gas a Real Explosion Risk?

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In summary, last night a person witnessed a redneck pumping gasoline with a lit cigarette in his mouth, which is likely against the law. The conversation then turned to the likelihood of a catastrophic explosion and the severity of possible damage from this act. The group discussed the various ignition temperatures of different fluids and the low probability of a cigarette causing an explosion at a gas station. They also mentioned the myth of dropping a cigarette into a gas tank and the real danger of static electricity. Overall, it was concluded that while it is possible for a cigarette to ignite gasoline, it is unlikely and not worth the risk.
  • #1
techmologist
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Last night I was coming out of the convenience store and saw this redneck pumping gasoline with a lit cigarette in his mouth. I'm pretty sure this is against the law here. Is it very likely to cause a catastrophic explosion? Or is it just the severity of the possible damage that makes it a bad idea, even if it is unlikely?
 
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  • #2
I say, "Stand at a safe distance and watch Darwin In Action!"
 
  • #3
I read a description of the burns and other injuries (in my JEMS magazine) sustained by a man who was leaned over filling a gas can at the pump, while smoking. Apparently a hot ash fell into the can, and it exploded. He ended up with burns over most of his body, as well as lung problems from being put out with a fire extinguisher. He died a day or two later.

Yeah, stay well back.
 
  • #4
berkeman said:
problems from being put out with a fire extinguisher. He died a day or two later.

Thats a broad meaning of "being put out".
 
  • #5
It's possible to ignite gasoline with a cigarette, but just barely.

http://mythbustersresults.com/special7

Ignition temperature for various fluids

Gasoline: 800 deg
Propane: 871 deg
Flour: 748 deg
Acetylene gas: 571 deg
60 Octane gas: 536 deg
Paper: 446 deg
#1 Fuel oil: 444 deg
Wood: 392 deg

Cigarette temperature when inhaling: about 550 deg

There's also a small possibility of vapors accumulating and igniting (vapors have a lower ignition temperature). While you could accumulate vapors in a gas can, it's very unlikely that enough vapors would accumulate in an open air gas station while refueling your car - especially if there's any kind of breeze.

It's not particularly easy to drop a lit cigarette into your gas tank nowadays, especially if you've got the nozzle stuck in the refueling tube, so, while it's possible the vapors in your car's gas tank could be ignited, the odds aren't very good.
 
  • #6
Chi Meson said:
I say, "Stand at a safe distance and watch Darwin In Action!"

:smile:
 
  • #7
BobG said:
It's possible to ignite gasoline with a cigarette, but just barely.

http://mythbustersresults.com/special7

Ignition temperature for various fluids

Gasoline: 800 deg
Propane: 871 deg
Flour: 748 deg
Acetylene gas: 571 deg
60 Octane gas: 536 deg
Paper: 446 deg
#1 Fuel oil: 444 deg
Wood: 392 deg

Cigarette temperature when inhaling: about 550 deg

There's also a small possibility of vapors accumulating and igniting (vapors have a lower ignition temperature). While you could accumulate vapors in a gas can, it's very unlikely that enough vapors would accumulate in an open air gas station while refueling your car - especially if there's any kind of breeze.

It's not particularly easy to drop a lit cigarette into your gas tank nowadays, especially if you've got the nozzle stuck in the refueling tube, so, while it's possible the vapors in your car's gas tank could be ignited, the odds aren't very good.

Beat me to it! Bah... That was a good episode. One of the guys literally knelt down on the ground with this cigarette in his mouth puffing on it so it gets hot right over top of a puddle of gasoline and it still wouldn't light.

I was waiting to watch his face catch on fire, but it never happened...
 
  • #8
IIRC, didn't he drop the cigarette into a puddle of gasoline and it extinguished the cigarette?

Of course with my luck, my static cling will blow up the entire station.
 
  • #9
I've put out many cigarettes in gasoline to mess with friends. Never ignited the gas.

I wouldn't do it in a hot arid region though, assuming the fumes are more volatile.
 
  • #10
The only trouble is when a cigarette ejects a 'spark' on that rare occasion as I've seen them do---THAT would ignite fumes.
 
  • #11
If you're driving behind another vehicle, you can usually tell which side their gas filler tube is located. It's almost always on the opposite side of the tailpipe to reduce the chance of pouring gasoline on a hot exhaust system.

Actually, it's on the opposite side of the muffler, so you can get fooled by dual exhaust or by mufflers that run laterally (such as the Dodge Dynasty).

Realistically, your exhaust system should be less than 600 deg that far back along the exhaust, but the exhaust system on a malfunctioning car can get hotter - especially with a catalytic converter.
 
  • #12
BobG said:
It's possible to ignite gasoline with a cigarette, but just barely.

http://mythbustersresults.com/special7

Ignition temperature for various fluids

Gasoline: 800 deg
Propane: 871 deg
Flour: 748 deg
Acetylene gas: 571 deg
60 Octane gas: 536 deg
Paper: 446 deg
#1 Fuel oil: 444 deg
Wood: 392 deg

Cigarette temperature when inhaling: about 550 deg

There's also a small possibility of vapors accumulating and igniting (vapors have a lower ignition temperature). While you could accumulate vapors in a gas can, it's very unlikely that enough vapors would accumulate in an open air gas station while refueling your car - especially if there's any kind of breeze.

It's not particularly easy to drop a lit cigarette into your gas tank nowadays, especially if you've got the nozzle stuck in the refueling tube, so, while it's possible the vapors in your car's gas tank could be ignited, the odds aren't very good.

Thanks for this info. I figured there was a lot of mythologizing about gasoline and cigarettes on account of what you see at the movies, not to mention propaganda from anti-smoking zealots. But still, it seems pretty stupid to smoke at the pump. I don't doubt that some of the horror stories of accidents caused this way are true. Even if it is unlikely.

I wonder what the burning temperature of a wood kitchen match is. I know from experience that it is no trouble at all to light a little cupcake/pie tin full of gasoline with one of those "strike anywhere" matches. But then, maybe I was really igniting the fumes that accumulated over the liquid.

Chi Meson said:
I say, "Stand at a safe distance and watch Darwin In Action!"

Heh. Yeah, that's exactly what popped in my mind. Of course, it doesn't work that way. From a purely evolutionary point of view, that gentleman is doing much better than I am. He probably has a number of children, some of whom will survive to reproducing age. :smile:
 
  • #13
BobG said:
It's possible to ignite gasoline with a cigarette, but just barely.

http://mythbustersresults.com/special7

Ignition temperature for various fluids

Gasoline: 800 deg
Propane: 871 deg
Flour: 748 deg
Acetylene gas: 571 deg
60 Octane gas: 536 deg
Paper: 446 deg
#1 Fuel oil: 444 deg
Wood: 392 deg

Cigarette temperature when inhaling: about 550 deg

There's also a small possibility of vapors accumulating and igniting (vapors have a lower ignition temperature). While you could accumulate vapors in a gas can, it's very unlikely that enough vapors would accumulate in an open air gas station while refueling your car - especially if there's any kind of breeze.

It's not particularly easy to drop a lit cigarette into your gas tank nowadays, especially if you've got the nozzle stuck in the refueling tube, so, while it's possible the vapors in your car's gas tank could be ignited, the odds aren't very good.

Nowadays the gas stations sell gasoline with 10% ethanol in them. I wonder how much lower that brings the flash point down, considering flash point of ETOH is 55 deg F
 
  • #14
There have been a number of documented cases of gasoline fires started by static discharge, so I'd give any smoking gas-pumpers a wide berth.
 
  • #15
turbo-1 said:
There have been a number of documented cases of gasoline fires started by static discharge, so I'd give any smoking gas-pumpers a wide berth.

When you say "a number," what do you mean? Because 1 would be a number. I've heard of this happening 2 or 3 times in the past 15 years or so. It seems pretty hard to accomplish.

I don't know if they still do this, but at one point, gas stations used to have instructions to turn your cell phone off, because the electronics inside could ignite the fumes. I have no idea what they based that on, though.
 
  • #16
It's hard to say a static discharge fire is more likely when smoking at a gas pump is illegal. Every time you put the nozzle in the filler tank, there's a chance of static discharge while it's rare for a person to smoke while filling their gas tank.

Still, having a static discharge right at the area where fuel vapors would be escaping would seem to be a lot more likely to result in a fire than smoking in general. You'd have to put the cigarette near the area where the vapors were.

The cell phone warnings are almost certainly bogus, though.
 
  • #17
Jack21222 said:
When you say "a number," what do you mean? Because 1 would be a number. I've heard of this happening 2 or 3 times in the past 15 years or so. It seems pretty hard to accomplish.

I don't know if they still do this, but at one point, gas stations used to have instructions to turn your cell phone off, because the electronics inside could ignite the fumes. I have no idea what they based that on, though.
In this case "a number" as documented by the petroleum industry is at least 150, backed up by video-recordings at gas stations.

I once had a boss that was a congenital liar. He would lie when the truth would serve him better. He once told me to tell a lady that "a number" of people had informed me of her husband's death when in fact it was one insider who knew of the man's collection of CW swords. I refused to lie to her and he threatened to fire me on the spot. I refused again, and he fumed and stormed off. I made the lying jerk millions of dollars and turned his business around, and he had the temerity to demand that I act as unethically as he did, day-in, and day-out.
 
  • #18
turbo-1 said:
In this case "a number" as documented by the petroleum industry is at least 150, backed up by video-recordings at gas stations.

I once had a boss that was a congenital liar. He would lie when the truth would serve him better. He once told me to tell a lady that "a number" of people had informed me of her husband's death when in fact it was one insider who knew of the man's collection of CW swords. I refused to lie to her and he threatened to fire me on the spot. I refused again, and he fumed and stormed off. I made the lying jerk millions of dollars and turned his business around, and he had the temerity to demand that I act as unethically as he did, day-in, and day-out.

150 over what time period? I don't doubt the number, I'm just trying to figure out exactly how common it is. Is this 150 per year, or 150 over the last 30 years, or something in between?
 
  • #19
Jack21222 said:
150 over what time period? I don't doubt the number, I'm just trying to figure out exactly how common it is. Is this 150 per year, or 150 over the last 30 years, or something in between?
Since 1999, I believe. Google it.
 
  • #20
turbo-1 said:
Since 1999, I believe. Google it.

Trying to google it now. Came up with http://www.snopes.com/autos/hazards/static.asp so far, which references a PEI study that says "to date" there have been 150, but doesn't list a starting time.

The link to the PEI study from snopes is a dead link.

Through a little more googling PEI, I came up with a PDF file: http://www.pei.org/Portals/0/resources/documents/Refueling%20Fire%20Incidents.pdf

This states there have been 173 reported from 1992 to 2008, which is a span of 16 years.

Averaging that out, appears that there are about 17 gasoline fires per year. The PEI estimates that Americans refill their vehicles 11 to 12 billion times a year, so a gas station fire is almost a 1 in a billion shot. Additionally, in almost every case, the fire results in either no injury or a minor injury (singed hair). Only one person was killed within the time frame of this study.

I guess my point is that you could probably hold a road flare at a gas station and not have any problems, unless there's some freak pocket of gasoline vapor in the right place and the right time.

*edit*

Reading the details of each incident, it appears that almost all of them (if not all, didn't read every one, but all of the first 20ish) were caused by a spark directly at the fuel tank. None (that I've read so far) were caused by a spark more than a few inches away from the nozzle. Smoking a cigarette while refueling appears to be mostly safe as long as you don't put the cigarette next to the nozzle or gas cap while pumping.
 
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  • #22
BobG said:
http://www.esdjournal.com/static/Static_Fires.pdf

161 from 2000 to 2004

People fuel their vehicles about 16 billion to 18 billion times a year.

Looks like that study is from around the world, the one I posted was only from the US.
 
  • #23
I won a bet with my last boss over this issue and there may be a thread around here where I talked about it a few years ago:
Evo said:
Of course with my luck, my static cling will blow up the entire station.
That is a typical cause of fire at a gas station and there are a number of videos on youtube of it happening. It's pretty entertaining since it always happens right when you go to grab the nozzle from the tank, shock it, and a flame shoots out and goes up your arm. Very funny stuff.

I also seem to remember someone like the NTSB tracking stats on them and it happens several times a year IIRC. I'll look for the stats...
 
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  • #24
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  • #25
Here's a news report on the issue...not all end with just some humor... http://www.cbsnews.com/video/watch/?id=639389n&tag=related;photovideo

...It says 78% happen to women because more women than men get back in their cars.

Here's an article with some stats:
Renkes said he has studied the issue of fires at gas pumps for 12 years and in that time there have been nearly 200 fires which appear to have been caused by static electricity.
http://abclocal.go.com/wpvi/story?section=news/local&id=7320077

...but deaths are rare because as you see in the video, it isn't actually all that easy to make the fire spread, nor does a little fire tend to lead to an immediate explosion.

[edit] Heh, sorry guys, I didn't see the last few posters already did that research.
 
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  • #26
Some gas stations have fire suppression systems. They can be triggered accidentally. Don't push the big red button if you don't know what it is.

 
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  • #27
You're being a little hard on Evo here, Russ. Now, if she was refueling her chainsaw in the back of her pickup truck equipped with a BedLiner, that would be different...
 
  • #28
edward said:
Don't push the big red button if you don't know what it is.

Now there's some good advice in general. o:)
 
  • #29
berkeman said:
You're being a little hard on Evo here, Russ. Now, if she was refueling her chainsaw in the back of her pickup truck equipped with a BedLiner, that would be different...
Is the chainsaw running?
 
  • #30
While pumping gas, if you can smell gas you are in a flammable atmosphere, step to clean air and watch your gas pump. Please do not leave children strapped into car seats while pumping gas there is just no way you can remove them fast enough. Remember you may not be smoking but what about the guy on the other side of the pump or the young mother on her cell phone. I am surprised there are not more accidents at the pump, but my favorite is the drivers that upon finding their car is on fire will pull into the closest gas station.
 
  • #31
petm1 said:
the young mother on her cell phone

Yep, young mothers, especially when talking with their husbands refusing to help with kids/shopping/laundry, tend to blow up quite often.

But I have never seen one exploding into flames. More like tears, and that puts fire out.
 
  • #32
petm1 said:
the young mother on her cell phone.

What's wrong with cell phones?

Did you know there has never in the history of cell phones been a gas station fire caused by a cell phone? Never. Not one. You're quoting an urban legend.

The Mythbusters did their best to try and make one blow up. They put in in a small box saturated with gasoline fumes, and if I recall correctly, even removed the cover from the phone, but still couldn't make it blow.
 
  • #34
Completely off topic, she wasn't smoking.
 
  • #35
Borek said:
Completely off topic, she wasn't smoking.

She was smoking. Smoking hot.
 

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