fire-retardant vs fire-resisting

fire-retardant and fire-resisting both are adjectives.

Word	Noun	Adjective	Verb	Adverb
fire-retardant	No	Yes	No	No
fire-resisting	No	Yes	No	No

As adjectives, fire-retardant and fire-resisting are synonyms defined as:

Other synonyms of fire-retardant include fire-resistant, fire-resistive.

fire-retardant (adjective)	fire-resisting (adjective)
difficult to burn	difficult to burn