sodium 4-hydroxy-5-[(2-methoxy-4-nitrophenyl)azo]-6-(phenylamino)naphthalene-2-sulphonate;Acid Black 31;4-Hydroxy-5-[(2-methoxy-4-nitrophenyl)azo]-6-(phenylamino)-2-naphthalenesulfonic acid sodium salt;C.I.17580;C.I.Acid Black 31;sodium,5-[2-(2-methoxy-4-nitrophenyl)hydrazinyl]-4-oxo-6-phenyliminonaphthalene-2-sulfonate;sodium 4-hydroxy-5-[(2-methoxy-4-nitrophenyl)azo]-6-(phenylamino)naphthalene-2-sulphonate ISO 9001:2015 REACH;C.I.Acid Black 31:C.I.17580