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Inhaling Petrol Fumes

Tonight at 6PM the channel 7 news will have a special report about the dangers of inhaling fumes while filling cars with petrol. I’m blogging now because based on past experience I expect almost no technical content in the report and that the advert for the news show contains everything that is useful.

The advert showed that they had used some film technique to show the fumes leaving the petrol tank while fuel is pumped in. It was obvious that the fumes were rising past the face of the man who was filling the tank. Not that this is really news, if you observe closely when fuel is pumped into a car you can see where the vapor escapes as the slight difference in density causes whatever is behind it to shimmer slightly.

For a long time the Prius has had a bladder inside the fuel tank which expands and contracts to match the fuel volume [1]. This greatly reduces the evaporative loss of fuel when the car is parked and the ambient temperature changes and also when fuel is pumped in. So it seems that in regard to the issue of fuel vapor poisoning the driver, the Prius has been better than other cars for about 10 years. Apparently Toyota have developed a new system that they have implemented in the Hybrid Lexus and the new Hybrid Camry which involves “vapor recovery”, this is supposed to give similar benefits in terms of not releasing petrol fumes into the environment but without limiting the capacity of the fuel tank in cold weather (a common complaint about the Prius). I have not been able to find any technical information on how this works (please let me know if you know a good web page about it).

The next issue is that any car which gives good fuel efficiency and has a reasonable size petrol tank will be better in regard to vapor releases. The less frequently you need to refuel your car the less fuel vapor you will inhale. I predict that channel 7 will not suggest that people drive fuel efficient cars, they are probably more likely to go for hand-wringing about the “inevitable” health problems, or make vague claims that the government should do something about it. The fact that the news show in question is immediately followed by “Today Tonight” (one of the tabloid TV shows) is an indication of the likely quality.

A final issue is the puddles of fuel that you commonly see at petrol stations. People regularly spill reasonable quantities of petrol and Diesel fuel and it just accumulates on the concrete. It’s not uncommon that I will have to drive with my car windows open after buying petrol due to the petrol that I stood in evaporating from my shoes. Apart from training people to not be stupid when refueling their vehicles I can’t think of any way of solving this problem. A petrol station employee once told me that it’s not uncommon for people to refuel cars with their young children standing within splash range of the fuel nozzle. If people can’t manage to avoid splashing their children with fuel then it seems that it will be impossible to get them to do anything reasonable or intelligent regarding the refueling process.

9 comments to Inhaling Petrol Fumes

  • Anonymouse

    I wonder to what extent full service stations might address these issues. At least in theory, an employee would have somewhat more experience handling gasoline than a random driver, even if you accept that “gas station attendant” has very low job qualifications. Some US states specifically prohibit self-service stations, for various reasons including safety. (Also somewhat for employment protectionism, but not necessarily as a prime motivation.)

  • John

    What a cock you are, Coker. Nice research – you haven’t even watched the report.

  • As anonymous mentions, New Jersey requires that all fueling stations are “full serve”, meaning you can’t get out and fill you own tank. Surprisingly, the gas there is cheaper than some of the surrounding states.

    My dad worked on some compressed natural gas projects, and he explained that since the gas is compressed, the fueling process is much different than liquid gasoline. The link between the pump and the tank must be sealed so there is little to no fumes emitted.

    I wouldn’t be surprised if at some point fueling stations become fully automatic, where you drive up and a robotic arm automatically plugs into your cars and fills it up.

  • etbe

    Anonymouse: Good point. When I first considered the issue it occurred to me that if I went to a mythical “full service” station (which don’t exist in any of the parts of Australia where I have driven in the last 14 years or so) then an employee of the petrol station would inhale the fumes instead of me. Pushing the consequences of my actions onto someone else in that manner isn’t my style so I didn’t think any more about it. But now that you mention it someone who knows what they are doing could avoid spilling petrol and improve things for everyone.

    John: Allow me to rewrite your comment in a more reasonable manner: “As an employee of the Channel 7 network I’m disappointed in the blog commentary about our shows, please don’t criticise my work based on an advert and also please watch the show and update your post if your expectations prove incorrect”.

    John: Here’s my response to the improved version of your comment:
    Thanks for your interest, I’m flattered that employees of the Channel 7 network read my blog and feel compelled to comment on it. I will certainly watch the show in question and update this post accordingly.

    Albert: A significant portion of the cost of petrol is tax, in most places other than the US the tax comprises the majority of the petrol price. So a minor variation in the petrol tax could overshadow the small increase in labor for a full-service station (which probably up-sells more mechanical work, car-wash services, etc).

    It’s a good point that LPG should have much less leakage when refueling. But I wonder how that compares to the LPG that is lost when a vehicle is parked for a long time. I guess that LPG which seeps out of the tank of a parked car (and petrol which evaporates) doesn’t matter much in terms of the health issues unless you have an enclosed garage that is attached to your house.

    I am willing to bet that the process of refueling with petrol will never become automatic. Petrol prices are steadily increasing and car use is slowly decreasing. New technology tends not to be introduced into a dying industry. There are however already designs for fully automatic recharge stations for electric vehicles.

  • etbe

    Damn, I missed the first ~20 minutes of the news show in question which apparently contained the article on petrol fumes.

    John, do you have any inside knowledge on how to get access to this? Does Channel 7 do what some of the US networks do and publish transcripts of it’s shows? If so where can I find them? The Yahoo7 web site is awfully disorganised (the “news” link tells me about new TV shows now about “the news”).

    Is there anyone at 7 who I should contact with suggestions? Or should I just blog my opinions and rely on you and other “7” employees to spread the word internally?

  • John Hughes

    Russell, I find that smoking a cigarette as I fill the tank helps avoid most of the noxious influence of the fumes.

    Please pass this tip on to people who like to splash it around.

    TTFN.

  • etbe

    http://en.wikipedia.org/wiki/Kindling_point
    http://en.wikipedia.org/wiki/Fire

    There is a rumor that a cigarette is not hot enough to ignite petrol. But petrol has a kindling point of between 246C and 280C and a cigarette always burns at 400C or more.

    I have a vague recollection of a Mythbusters episode where they had trouble igniting a sample of petrol with a cigarette due to the difficulty getting the right mixture with air. It’s not an experiment you would want to repeat at a petrol station though. ;)

  • “The next issue is that any car which gives good fuel efficiency and has a reasonable size petrol tank will be better in regard to vapor releases.”

    If you pump in, say, 20 litres of fuel, you will displace 20 litres of vapour (clever bladder systems excepted, and I’m still not sure about that as all it seems to do is obviate the need for a purge cannister).

    There is an issue about whether you stand down wind of that of how much fuel there is in the vapour (basically, the saturation vapour pressure at the conditions in your tank), but beyond that, not much changes.

    I’ve long thought that the pump should contain a little device that sucks the gas in locally to the nozzle and condenses any fuel there, but that’s just me…

    “A final issue is the puddles of fuel that you commonly see at petrol stations. People regularly spill reasonable quantities of petrol and Diesel fuel and it just accumulates on the concrete.”

    Petrol evaporates fairly quickly in most circumstances. Diesel is different though, and can hang around quite a bit.

    Here in Europe, I don’t see this issue much. I think this is one of the hidden advantages of having expensive petrol/diesel…

  • Fred

    “If people can’t manage to avoid splashing their children with fuel then it seems that it will be impossible to get them to do anything reasonable or intelligent regarding the refueling process.”

    On the bright side, natural selection will fix the issue.