Synonyms: disodium 3-[(2,4-diaminophenyl)azo]-5-hydroxynaphthalene-2,7-disulphonate;3-[(2,4-Diaminophenyl)azo]-5-hydroxy-2,7-naphthalenedisulfonic acid disodium salt;2,7-Naphthalenedisulfonic acid, 3-((2,4-diaminophenyl)azo)-5-hydroxy-, disodium salt;2,7-Naphthalenedisulfonic acid, 3-(2-(2,4-diaminophenyl)diazenyl)-5-hydroxy-, sodium salt (1:2);2,7-Naphthalenedisulfonic acid, 4-hydroxy-6-((2,4-diaminophenyl)azo)-, disodium salt;Einecs 267-981-7