Like many safety professionals, I learned there is a HUGE difference in flammable liquids the HARD WAY. Having a strong background in fire/HAZMAT, even as an IFSTA instructor 20 years ago; I thought flammable liquids were all about flash points and LEL. To an emergency responder, that may work, but as a safety engineer responsible for a PSM/RMP-covered process containing non-conductive flammable liquids, there is much more.