Synonyms: 2,7-Naphthalenedisulfonic acid, 6-amino-4-hydroxy-3-7-sulfo-4-(4-sulfophenyl)azo-1-naphthalenylazo-, compd. with 2,2,2-nitrilotrisethanol (1:4);2,7-Naphthalenedisulfonic acid, 6-amino-4-hydroxy-3-[[7-sulfo- 4-[(sulfophenyl)azo]-1-naphthalenyl]azo]-, compd. with 2,2’,2’’-nitrolotris[ethanol] (1:4)