C.I.Direct Red 4, 2-Naphthalenesulfonic acid,4-hydroxy-7-[[[[5-hydroxy-6-(phenylazo)-7-sulfo-2-naphthalenyl]amino]carbonyl ]amino]-3-[(6-sulfo-2-naphthalenyl)azo]-,trisodium salt, DIRECT23, 4-Hydroxy-7-[[[[5-hydroxy-6-(phenylazo)-7-sulfo-2-naphtyl]amino]carbonyl]amino]-3-[(6-sulfo-2-naphtyl)azo]-2-naphthalenesulfonic acid trisodium salt, trisodium 4-hydroxy-7-[[[[5-hydroxy-6-(phenylazo)-7-sulphonato-2-naphthyl]amino]carbonyl]amino]-3-[(6-sulphonato-2-naphthyl)azo]naphthalene-2-sulphonate,