self-rising flour vs self-raising flour

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

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

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

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

self-rising flour (noun)	self-raising 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