EINECS 269-301-4, 1,3'-Bipyridinium,1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-5'-(phenylazo)-,malate, 1,3'-Bipyridinium,1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-5'-(phenylazo)-,salt with hydroxybutanedioic acid (1:1), 1',2'-Dihydro-6'-hydroxy-4'-methyl-2'-oxo-5'-(phenylazo)-1,3'-bipyridinium malate, 1,3'-Bipyridinium,1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-5'-(2-phenyldiazenyl)-,2-hydroxybutanedioate (1:1),