toxic waste vs waste matter

toxic waste and waste matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
toxic waste	Yes	No	No	No
waste matter	Yes	No	No	No

As nouns, waste matter is a hypernym of toxic waste; that is, waste matter is a word with a broader meaning than toxic waste:

toxic waste: poisonous waste materials; can cause injury (especially by chemical means)
waste matter: any materials unused and rejected as worthless or unwanted

Other hypernyms of toxic waste include waste, waste material, waste product.

toxic waste (noun)	waste matter (noun)
poisonous waste materials; can cause injury (especially by chemical means)	any materials unused and rejected as worthless or unwanted