sensitiser vs sensitizer

sensitiser and sensitizer both are nouns.

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

As nouns, sensitiser and sensitizer are synonyms defined as:

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

sensitiser (noun)	sensitizer (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