Could my bedding cause a fire?
Sereen asks: The other day I was sleeping and I woke up. I had turned around and rubbed my hands across my sheets when suddenly I had noticed white sparks come out. Could this possibly cause a fire?
Chris Smith put Sereen's question to Imperial College's Stuart Higgins...
Stuart - No, and that’s because the energy that comes out of those sparks is far too small to ignite the material that your bed is made of. But, actually, there are circumstances where it could be a problem and the classic example is at a petrol station.
Chris - How many people sleep in a petrol station, Stuart?
Stuart - That’s true, that is very true. So if you’re in bed you're okay, but the way you have to worry about this is something like… Well, actually, do you know why you have to hold the handle in the UK? So, if you go the U.S or Germany you don’t have to hold the handle while you’re filling the car.
Chris - At the petrol pump?
Stuart - At the petrol pump yes.
Chris:: Because it’s earthed!
Stuart - Yes, exactly. They’ve found that if you have a system where you go and put the petrol pump in, you squeeze the handle and you lock it in place so you can walk away. People tend to go and sit back in their cars and as they get out of their car again their clothes are rubbing against the seat and it’s generating this static electricity. And the first thing you then touch is the petrol pump, with the vapour, and then in that case the energy from the spark, which is about 8 kilovolts, is enough to ignite the petrol fumes. Very low risk, doesn’t happen a lot, very, very few reported cases but it’s one of the reasons why, in the U.K., you have to squeeze the handle while you’re doing it.
Chris - Is it fashion dependent? People who have a persuasion towards a particular latex or nylon underwear or something? Are they more prone to having a fuel tank fire?
Stuart - Potentially. The ability to charge clothes by rubbing them against different surfaces depends on what that material is and certain materials, yes, are easier to charge up than others.
Chris - You can sleep easy on that piece of advice. Your bed sheets are not going to cause an inferno while you’re sleeping.