respirator vs gasmask

respirator and gasmask both are nouns.

Word	Noun	Adjective	Verb	Adverb
respirator	Yes	No	No	No
gasmask	Yes	No	No	No

As nouns, respirator and gasmask are synonyms defined as:

respirator and gasmask: a protective mask with a filter; protects the face and lungs against poisonous gases

Other synonyms of respirator include gas helmet.

respirator (noun)	gasmask (noun)
a breathing device for administering long-term artificial respiration	a protective mask with a filter; protects the face and lungs against poisonous gases
a protective mask with a filter; protects the face and lungs against poisonous gases