2-Naphthalenesulfonic acid, 5,5'-(sulfonylbis(3,1-phenyleneazo))bis(6-amino-4-hydroxy-, disodium salt 70210-45-6 Disodium 5,5'-(sulphonylbis(3,1-phenyleneazo))bis(6-amino-4-hydroxynaphthalene-2-sulphonate) EINECS 274-443-5