flash point vs criticality

flash point and criticality both are nouns.

Word	Noun	Adjective	Verb	Adverb
flash point	Yes	No	No	No
criticality	Yes	No	No	No

As nouns, criticality is a hypernym of flash point; that is, criticality is a word with a broader meaning than flash point:

flash point: point at which something is ready to blow up
criticality: a critical state; especially the point at which a nuclear reaction is self-sustaining

flash point (noun)	criticality (noun)
the lowest temperature at which the vapor of a combustible liquid can be ignited in air	a state of critical urgency
point at which something is ready to blow up	a critical state; especially the point at which a nuclear reaction is self-sustaining