@ Havoc, thanks I was just getting ready to google myself b/c after asking my fiance, he said that oxygen lowers the flash point of petroleum (which I should have remembered, but I imagine the amount of petroleum is not enough to matter).
I was thinking that it must be b/c its not "sterile" and if I am breathing that essence in, I could be infecting myself... so the bug thing makes sense now.
Thanks for looking it up.