Oh right, I found it interesting because you see I have to use a blow torch connected to a gas cylinder for my Jewellery work, everything there is either rubber or metal, doesn't seem to be much plastic at all except perhaps the little cog you use on the blowtorch itself to release the gas, I'm paranoid about this sort of thing so It's nice having information pop up without me having to search for it.

Another tip by the way I noticed triplep hasn't mentioned, if you want to find out whether there's any small leaks anywhere get some washing up liquid and smear it over various places you think gas may be coming out. So if you've got a connection and you don't know whether it's been tightened up correctly put the washing up liquid on the connection, if there's even a tiny bit of gas leaking, the gas will create bubbles and you'll know things are not tightened up enough to prevent gas leaks.