self-raising flour vs self-rising flour

self-raising flour and self-rising flour both are nouns.

Word	Noun	Adjective	Verb	Adverb
self-raising flour	Yes	No	No	No
self-rising flour	Yes	No	No	No

As nouns, self-raising flour and self-rising flour are synonyms defined as:

self-raising flour and self-rising flour: a commercially prepared mixture of flour and salt and a leavening agent

self-raising flour (noun)	self-rising flour (noun)
a commercially prepared mixture of flour and salt and a leavening agent	a commercially prepared mixture of flour and salt and a leavening agent