The petrol is not dangerous. The fumes are quite a different matter however.
If you throw a lit match at some petrol, you will see that the petrol ignites before the match gets to it. The liquid would probably extinguish the match.
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I recently watched a show called Brainiac, which tested the 'flame and petrol fumes' with an experiment involving an old caravan, lots of petrol and fumes. The interesting part of the experiment is that the live flame didn't set the fumes and therefore the caravan alight - however the spark generated by the rubbing of nylon trousers brushing against each other.... BOOM! :)
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If the wind in wrong direction.fumes will blow up.usualy if in direction you have the naked flame/spark.If wind in direction away from live flame.fumes wont ignite.wind direction/draught may have changed..Liquid petrol is not flammable.Vapours are.
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Steve
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I am not normally in favour of sending people to jail unless they are a danger to the public or are persistant offenders, but in the case of these ganstas' and the contempt in their attitude I would quite happily throw the key away. I have seen a fire at a petrol station and it ain't funny.
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A garage near me shares the forecourt with a car sales operation .The cars are lined up within about 5 meters of the pumps and I have frequently seen people smoking as they looked around
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I saw one of my neighbours pouring petrol in to his car from a can and smoking.
He didn't even have a filler tube, he was just using a magazine folded to make a V-shaped channel!
I didn't risk going outside to warn him.
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Doctors have been telling us for years that smoking's dangerous.
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I was changing the clutch assembly on my Cresta once, very simple and quick job, but I had to do it twice because my neighbours little boy helped me by oiling it before I had put back the bell housing. My neighbour advised burning off the oil by soaking the plate in petrol and then setting fire to it. I had a 5 gall oil tin cut in half lengthwise, with a pint or less of 2 star petrol, under the eaves of the house to keep it out of the sun. I carried the plate about 10 metres away put it on a brick and lit it carefully. Then, I observed the flame travel back to the can, which promptly ignited. The flames were travelling through the air between the fumes from the drops of petrol which had fallen as I carried the plate. The liquid petrol did not burn, but the fumes above the can did, not big fire. I dropped a blanket over the can to smother the flames, and the blanket caught too. It took me minutes of hard shovelling of dirt to put it out.
If anyone sees smokers on the forecourt get out of the way QUICKLY. Perhaps they laugh at you because 'nobody ever caused a forecourt fire by smoking'. You might be the first to observe it, and it's better from a distance.
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And yet......
Back in the days when nice people actually served you with petrol (I was one of them, briefly), it was not at all unknown for the pump attendant to be carrying a lit fag while he served you.
We just had the decency to carry it in our free hand, behind our back.
Makes me shudder just thinking about it now.
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Many years ago I saw something that is one of those 'permanent' memories.
I was in a back street garage (reason for long forgotten). There was a chap there heating something in a vice using oxy/ acetelene gear. When the item was hot enough he did whatever he was doing and then dipped it into a nearby zinc bathtub half filled with what looked like water, to cool it down. BIG clouds of white smoke and he said that the 'thing' must have been hotter than he thought it was. Someone shouted "thats blinking petrol in there". Apparently someone had drained a fuel tank into the bathtub, and not mentioned it to anybody. No fire though !
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Many a story about lucky escapes from being severely burnt/death.from stupid mistakes/ie smoking/wearing clothing that is liable to make a spark when rubbed.AS in scratching yourself while filling up.Mobile phone use another one which could cause an explosion.It has been mentioned elsewhere.That its unlikely to happen.It seems a spark can be generated from the battery to terminal.I dont doubt this..But I dont think enough care is taken by some motorists.To prevent it happening.Attitude seems to be.Hasnt happened to me yet.I`ll worry when its too late type of attitude
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Steve
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In aviation circles, static electricity is taken seriously. Refuelling an aircraft, the aircraft is always earthed to an earthing point on the ground with a wire lead. When the fuel tanker arrives, it is also earthed to the point. Then the fuel tanker is earthed to the aircraft itself. After this the fuel hoses are run out and connected. This procedure is taken even when refuelling with jet fuel which is basically paraffin/kerosene, which is much less flammable than petrol. Even so, fires during refuelling have happened, usually when people have become lazy and have not followed the correct procedure.
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Steve I saw that Discovery Channel Mythbusters prog which debunks urban myths and they concluded this was one of them. Try as they might they couldn't ignite any petrol with various phones.
As for scratching yourself, well I try not to do that in public anyway! ;+D
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Growler: IIRC, the method of "testing" was at fault. The amount of vapour in the caravan was probably above the "upper explosive limit", i.e. not enough oxygen within the vapour cloud, at the point of ignition, as it was a confoned space. Towards the edges of a vapour cloud, i.e. in the open air after a spill of fuel onto the ground, the concentration will run from above the UEL, through the range of ignitibility and potential conflagration, down to and beyond the Lower Explosive Limit, where ignition can't occur. Concentrations below 1.4%, too lean to ignite, and above 7.6% too rich. Concentrations between these two, petrol vapour and air will burn.... Sorry to be boring, but not many grasp the essentials.
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"petrol vapour and air will burn." - given that there is also an ignition source, of course, as has been pointed out.
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"Personally i find dipping the end of a ciggy in the petrol makes them so much easier to light ;-)" I tried it once and the petrol put the fag out!
Are you sure you aren't getting confused with paraffin? Paraffin needs a "wick" to get it burning, unfortunately for some petrol doesn't. Contrary to some of the posts I've read both petrol fume and liquid petrol are highly flammable, not just the vapour. Vapour is heavier than air and can collect in ducts, drains etc. It can cause a track once ignited back to the original source and when it does at that point its the liquid that's burning, and boy does it burn. It's burning mechanism is so violent it can be called an explosion!
Not a substance to be under estimated in my book
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Right. Stupid question time.
I'll set the scene first. My mate has a Polo and in the bad floods ast year, drove through a puddle at 50. Unsurprisingly, the car stalled so Dad and I went to help him. Whilst Dad did....something and got it working, I noticed that when my mate turned it over, you could see a very definite spart near the back of the engine. I'm not mechanically minded but I'm pretty sure it wasn't the HT leads. In any event, you could see the spark.
So.....
Lets say I'm in the said Polo, park up at the petrol station, put petrol in and then start it. How come, given the concentration of fumes, the car doesn't blow up. (It doesn't otherwise my mate would be dead ;-))
I'm using that as an example but how come we don't all blow up when we start the engine?
Yours Stupidly,
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Adam
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Adam,
Fuel, oxygen and source of ignition all need to be together. If matey's car had been leaking fuel in the engine bay conflagration quite likely. When filling vapour at flammable concentration is concentrated around the filler area, which is why smoking is so stupid, but it's too far from the spark. If the car has an electrical fault causing arcing under the bonnet there is still a risk, might be one in ten or ten thousand, of explosion - do you feel that lucky?
Same with the mobiles. Assessment highlights potential risk with serious consequences but only a slight chance of occurence. Since nobody needs to use a mobile on the forecourt and the measure of making them safe is so difficult as to be impossible a ban is the only viable control measure.
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Thank you Bromptonaut.
Expert explanation - much appreciated. I won't be ringing anyone from the forecourt...nor will I be in my mate's car whilst he's getting petrol!
;-)
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Adam
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There is an HSE document, issued February 2005, to licencing authorities, at this link:www.hse.gov.uk/lau/lacs/65-59a.htm which goes into detail on mobile phones. Para 10 on phones etc is lengthy. Maybe HJ or the mods could decide how much to place on the board, if indeed they want to!
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I think this topic has been blown up out of all proportion...:-)
Seriously, it has never ceased to amaze me (as I disappear as fast as possible into the distance) why some people smoke whilst filling their vehicles at a petrol station.
Seems to me that they must use a goodly amount of life's luck as well as potentially putting other people's lives at serious risk.
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Since nobody needs to use a mobile on the forecourt and the measure of making them safe is so difficult as to be impossible a ban is the only viable control measure.
Point taken on the danger, but what do you suggest in this situation:
I was on a long journey as a passenger in someone else's car. Driver is my opposite number in a different organisation. I needed to make a call to a colleague without him overhearing, so I stayed in my seat made the call when he was filling the car with petrol.
Now I take the point about any use of the mobile being inadvisable ... but what was the best course of action?
Call from inside the car as I did?
Get out of car and call?
Go off to the derelict zone behind the back of the filling station?
Hop into the drivers seat, start the engine, quickly run over my driver, then zoom off to somewhere clear of the petrol fumes so that I can phone in safety?
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Get out of the car, walk away, and make your phone call.
But then you knew that, and no I wouldn't bother either.
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I'll be perfectly honest, I don't see how a phone (if used in the car) is any more dangerous than the radio, lights, central locking or whatever as I understand the danger is with the battery contacts and no so much the signal.
I presume the danger is mulitplied many times if used outside the car.
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Adam
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the danger is with the battery contacts and no so much the signal. I presume the danger is mulitplied many times if used outside the car.
Yes totally. The risk of causing a spark by using a mobile phone on a garage forecourt will only occur by dropping the thing on the ground. If you stay in the car and use it, you're not able to then drop it onto the tarmac/concrete surface of the forecourt - unless of course you lob the phone out of the window.
It was mentioned in one of the above links that the transmitting signal of a mobile is so small, that is it virtually insignificant, unlikea cb radio whcih has a more powerful transmitter.
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It was mentioned in one of the above links that the transmitting signal of a mobile is so small, that is it virtually insignificant, unlikea cb radio whcih has a more powerful transmitter.
In addition, the aerial of the CB is very often of the bare metal type, creating the potential for accidental grounding/spark, whereas the mobile phone version is totally enclosed in insulator.
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>>Call from inside the car as I did?>>
As far as I am aware, being inside a vehicle is perfectly acceptable.
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PeteM is quite right about the care taken in aviation. Also worht mentioning is that all radios must be turned off.
Radio transmissions are electromagnetic energy; they consist of a varying electrical field and a varying magnetic field. That electrical field is capable of creating a spark. That requires there to be a sufficient field, and a pair of suitable surfaces in a suitable orientation, and is therefore VERY unlikely. But, consider how many cars are fuelled each day. Multiply a very small number by a very large number and there is cause for concern.
Basically, I don't want it to be me. Stuartli - were you being poetic when you talked about the issue being blown up out of proportion? ;-)
NoWheels - I am surprised. How can you justify taking this risk, even if small, when you have chided me for suggesting that 31 is not really any riskier than 30? The latter is a small increment to an existing risk, whereas you created a risk with a huge downside where none was needed.
Anyway, the fresh air will do you good.
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>>Stuartli - were you being poetic when you talked about the issue being blown up out of proportion? ;-)>>
Just a play on words....
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NoWheels - I am surprised. How can you justify taking this risk, even if small, when you have chided me for suggesting that 31 is not really any riskier than 30?
Indeed, Patently, you are quite right. That's why I sought advice as soon as the hazard was brought to my attention.
The latter is a small increment to an existing risk, whereas you created a risk with a huge downside where none was needed.
Except that the advice is that a mobile poses next-to-no risk unless dropped, and that this tiny risk is reduced to nowt iunside the car. (Pity, I rather fancied the final Thelma-and-Louise option ... )
Anyway, the fresh air will do you good.
Probably, but my ciggie might get blown out as I walk clear of the fumes ;-)
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liquid that's burning
Nope
Petrol liquid can not burn. Ever. Its the vapour that burns. Yes the vapour is heavier than air and sits on top of the liquid, and when burning gives the impression that the liquid is on fire.
the explosion comes when petrol gets hot and vapourises even more, starts to boil and the whole lot becomes a pool of vapour or droplets.
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NoWheels,
The serious answer is to get away from the immediate vicinity of the forecourt. This is designated as a Zone 1 or Zone 2 area, depending where you are. The derelict area may be next to tank vent pipes so perhaps not a good idea.
A lot of people work towards ensuring electrical equipment is safe for use in a hazardous/gas vapour. Including me.
No mobiles are certified safe as far as I know.
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I wasna fu but just had plenty.
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Cue to an anonymous office somewhere in Whitehall.
Undersecretary Smithers knocks on the door titles ?Health & safety Executive?
Ah Smithers ? come in.
Sir, we have been running a risk assessment on Filling stations.
Yes?
Well sir, they contain thousands of litres of petroleum spirit swilling around, some have containers of propane and butane lying around, fire lighters, charcoal, and even gallons of alcohol.
Good god Smithers, if we called it HMS Filling Station the Spanish would ban it from their shipping ports!
Quite so Sir, anyway, we have made a study of the risks involved.
Mobile phones: small risk, low power, may ignite fumes.
Ban them in filling stations
Yes sir, but we have a higher risk. Cars. Using systems that generate tens of thousands of volts causing large sparks, Systems that use hundreds of amps to start, running at very high temperatures, indeed a car engine is a series of hardened cylinders containing hundreds of explosions. They are a considerable risk Sir.
What are you waiting for Smithers, Ban them in filling stations.
Yes Sir.
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Yes sir, but we have a higher risk. Cars. Using systems that generate tens of thousands of volts causing large sparks, Systems that use hundreds of amps to start, running at very high temperatures, indeed a car engine is a series of hardened cylinders containing hundreds of explosions. They are a considerable risk Sir. What are you waiting for Smithers, Ban them in filling stations.
Smithers hands in his draft order, which is checked out by lawyers, and handed over to the minister for aproval.
Except it doesn't get that far. Her private office refuse to put in the red box unless the briefing note covers one more area: incidence.
So, Smithers, how many of the car things do we have, and how many filling stations? What proportion of cars starting their engines in a filling station cause an explosion?
Smithers? Smithers!
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Cue to Daily Slander 15/03/05 - Front Page spread
Bold headlines scream
MINISTER BURNS BABIES
Undercover Daily Slander reporters have discovered that 90% of all fires in petrol stations are caused by cars. It is understood there are in excess of 25 million cars in use, and all of them visit petrol stations. Shockingly it has been learned that Minister Nowheels has been sitting on this report, and has left the appropriate banning order mouldering in her ministerial red box.
When contacted the ministers secratary said the minister could not be reached, she is waiting in a bus queue and refusing to use her mobile as its near a filling station.
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Haha. This is great fun!
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Adam
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Daily Slander 28/03/05 - Front Page box
CORRECTION
"We regret that the Daily Slander's front-page article entitled 'Minister Burns Babies' may have been unintentionally misleading.
We accept that Ms NoWheels is not a government minister, does not have a red box, and that country wil be overrun with flying pigs long before she ever gets such a job.
We also accept that no babies have been burnt at petrol stations, and no proposal exists within government to ban cars from petrol stations.
The Daily Slander has been pleased to make a substantial contribution to the Plain English Campaign, and to make a substantial cut in our reporters expense allowances for lunch."
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>>No mobiles are certified safe as far as I know.>>
The link provided earlier states:
"Mobile telephones should not be used by customers or forecourt staff whilst actually dispensing petrol into fuel tanks or containers;
"During petrol deliveries mobile telephones should not be used on those parts of the site that have been designated as hazardous areas by the site operator or the driver;
"Mobile telephones should not be used during other petrol handling operations or during the maintenance of petrol equipment unless a specific assessment shows the risks are negligible;
"There is no need to restrict the use of mobile telephones, with respect to the safe keeping of petrol, at other times or in other areas of the forecourt. This includes in the shop, in motor vehicles parked on the forecourt or in other non-hazardous areas."
The last paragraph would seem to clear up your worries.
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This is the HSE's advice, leading up to the list of points Stuartli has posted:
"Generally mobile telephones are not designed and certified for use in explosive atmospheres. Their use can also create a serious distraction for people carrying out dispensing activities. Radio transmissions from individual mobile telephones are generally too low to induce dangerous electric currents in nearby equipment and the risk of incendive sparking from the battery is low, however, they should not be used in the hazardous areas that exist when actually dispensing petrol. Neither should they be used in the hazardous areas around the fill and vent pipes during petrol deliveries. Rather than applying a total prohibition on the use of mobile telephones on petrol forecourts which has resulted in some anomalies and frequent abuse to staff, the following controls are recommended:"
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Don't know if this helps- but had to call the Police from motorway services last week (someone walking up the hard shoulder). Was told could use mobile so long as not stood under the apron.
As for matey- no sign of broken down car, and although he was 1/2 mile from a junction was going in opposite direction with back to traffic.
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About Adski's question on sparks around the engine, problems in this area are not unknown. On my Jaguar XJ12 there is a known hazard for this. As the rubber fuel injection hoses age and get a good cooking from the heat of the engine they get brittle. Taken to the extreme of neglect, they can leak. There are twelve spark plugs and thirteen high tension leads in a small space shared with the fuel injection piping. A serious number of XJ12s and XJ-S V12s have had engine fires. This is more likely in the USA, where there are also four very hot catalytic converters just under the engine to cook the engine bay very nicely. The solution is to examine the fuel injection hoses regularly, and replace them at the first sign of deterioration, and at the very longest, every five years. Ditto for the HT leads. The same can apply to a number of other cars with packed engine bays.
I remember that when unleaded fuel was first introduced in New Zealand around 1997, the change in its composition, aided by an error in the initial formulation, caused various fuel system components to dissolve on a number of cars. Compensation was paid by the fuel companies, and it must have been a pretty penny too. I filled the Jag up on leaded fuel and avoided the first batch of unleaded, as I had a premonition about the new fuel, which was, in the event, justified.
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>>I noticed that when my mate turned it over, you could see a very definite spart near the back of the engine.
Get your mate to check the flexible earth bond between the engine and the body. The vibration hardens the copper braid and sometimes it breaks, but the ends still touch. When the starter motor is turning the current has to return via the braid, several hundred amps, it will spark merrily.
Petrol fumes will not ignite if the conditions for burning are not correct, i.e., within the higher and lower explosive limits. That is why it so rarely happens. But, somewhere in the vicinity the conditions ARE correct, and you might be unfortunate enough to find the spot. People play Russian roulette over and over until they get the bullet in the right place. It's then pointless to say to them "I told you!!"
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