ok, propylene oxide (PO) is nasty stuff. it's a skin-absorbable poison that could kill you if enough gets in you. it'll burn your skin, causes cancer, react badly with certain metals like copper...all kinds of bad things. actually, now that i think of it, nitromethane is just as bad lol also it's very hard to store, must be kept cool and in a mtal can. it will pass right through the walls of your plastic fuel jug. stick with nitro my friend.
but, if ya REALLY GOTTA GET SOME.... here ya go
http://www.autoshopracingengines.com/parts.htm (scroll down a little)