1,5-Naphthalenedisulfonic acid, 3,3'-(carbonylbis(imino(2-methyl-4,1-phenylene)azo))bis-, tetrasodium salt 29684-47-7 3214-47-9 C.I. DIRECT YELLOW 50 C.I. Direct Yellow 50 (VAN) C.I. Direct Yellow 50, tetrasodium salt C.I. Direct Yellow 50, tetrasodium salt (8CI) Direct Fast Yellow R Direct Lightfast Yellow K Direct Yellow 50 EINECS 221-728-7 NSC 47763 Sirius Light Yellow R Sirius Light Yellow R Extra Tetrasodium 3,3'-(carbonylbis(imino(2-methyl-4,1-phenylene)azo))bisnaphthalene-1,5-disulphonate