plural vs Epsom salts

plural and Epsom salts both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural	Yes	Yes	No	No
Epsom salts	Yes	No	No	No

plural (noun)	Epsom salts (noun)
the form of a word that is used to denote more than one	(used with a singular noun) hydrated magnesium sulfate used as a laxative
	hydrated magnesium sulfate that is taken orally to treat heartburn and constipation and injected to prevent seizures

plural (adjective)	Epsom salts (adjective)
grammatical number category referring to two or more items or units
composed of more than one member, set, or kind