Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Smoking at the fillin' station

  1. Mar 15, 2010 #1
    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?
     
  2. jcsd
  3. Mar 15, 2010 #2

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    I say, "Stand at a safe distance and watch Darwin In Action!"
     
  4. Mar 15, 2010 #3

    berkeman

    User Avatar

    Staff: Mentor

    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.
     
  5. Mar 15, 2010 #4

    Borek

    User Avatar

    Staff: Mentor

    Thats a broad meaning of "being put out".
     
  6. Mar 15, 2010 #5

    BobG

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
  7. Mar 15, 2010 #6

    Dembadon

    User Avatar
    Gold Member

    :rofl:
     
  8. Mar 15, 2010 #7
    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...
     
  9. Mar 15, 2010 #8

    Evo

    User Avatar

    Staff: Mentor

    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.
     
  10. Mar 15, 2010 #9

    Pythagorean

    User Avatar
    Gold Member

    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.
     
  11. Mar 15, 2010 #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.
     
  12. Mar 15, 2010 #11

    BobG

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
  13. Mar 15, 2010 #12
    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.

    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:
     
  14. Mar 15, 2010 #13

    cronxeh

    User Avatar
    Gold Member

    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
     
  15. Mar 15, 2010 #14

    turbo

    User Avatar
    Gold Member

    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.
     
  16. Mar 15, 2010 #15
    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.
     
  17. Mar 15, 2010 #16

    BobG

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
  18. Mar 15, 2010 #17

    turbo

    User Avatar
    Gold Member

    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.
     
  19. Mar 15, 2010 #18
    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?
     
  20. Mar 15, 2010 #19

    turbo

    User Avatar
    Gold Member

    Since 1999, I believe. Google it.
     
  21. Mar 15, 2010 #20
    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 [Broken]

    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.
     
    Last edited by a moderator: May 4, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Smoking at the fillin' station
  1. Who smokes ? (Replies: 133)

  2. Smoking Chimp (Replies: 16)

  3. Smoked potatoes (Replies: 11)

  4. About smoking (Replies: 21)

  5. Smoke alarm (Replies: 30)

Loading...