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 . 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.