FP is Non sequitor (and, I think your meaning “auto-ignition temp” which is much higher)
LEL and vapor build-up is more approrpriate.
No. FP is a test where the fluid in a dish is heated under a flame. When the flame ignites the vapors the temp the dish/fluid was at is called the flash point(open cup).
" LEL and vapor build-up is more approrpriate."
Those considerations are inherently contained in the flash point test.
I like it...