Synonyms of incombustible
fireproofSomething that is fireproof cannot be damaged by fire.
• soldiers wearing fireproof clothing
flameproofFlameproof cooking dishes can withstand direct heat, so they can be used, for example, on top of a cooker or stove, or under a grill.
• Heat the oil in a flameproof casserole.
Thesaurus for incombustible from the Collins English Thesaurus