2,7-Naphthalenedisulfonic acid, 3-((2,4-diaminophenyl)azo)-5-hydroxy-, disodium salt 2,7-Naphthalenedisulfonic acid, 4-hydroxy-6-((2,4-diaminophenyl)azo)-, disodium salt 67969-79-3 Disodium 3-((2,4-diaminophenyl)azo)-5-hydroxynaphthalene-2,7-disulphonate EINECS 267-981-7