TC, your nomex underwear is fire resistant, not fluid resistant, your vents and panels will allow hot and burning fluids in and while your underwear might not burn up your skin surly will. I also worked in a job that required Nomex clothing, will last longer in fire than jeans and a T-shirt... it will not keep you from being burned but if you want to prove something to yourself, pour a little gas on your crotch stretch panel while wearing your nomex underwear and then set it on fire. Video it and let us all know when you have that posted on utube.
Yes I have ridden on the salt, yes I wore nomex uw under my all cow leathers.