sensitizer vs sensitiser

sensitizer and sensitiser both are nouns.

Word	Noun	Adjective	Verb	Adverb
sensitizer	Yes	No	No	No
sensitiser	Yes	No	No	No

As nouns, sensitizer and sensitiser are synonyms defined as:

sensitizer and sensitiser: (chemistry) a substance other than a catalyst that facilitates the start of a catalytic reaction

sensitizer (noun)	sensitiser (noun)
(chemistry) a substance other than a catalyst that facilitates the start of a catalytic reaction	(chemistry) a substance other than a catalyst that facilitates the start of a catalytic reaction