2-Naphthalenecarboxylic acid, 3-hydroxy-4-((1-(sulfomethyl)-2-naphthalenyl)azo)-, calcium salt (1:1) 29779-09-7 3-Hydroxy-4-((1-(sulfomethyl)-2-naphthyl)azo)-2-naphthoic acid, calcium salt Calcium 3-hydroxy-4-((1-(sulphonatomethyl)-2-naphthyl)azo)-2-naphthoate EINECS 249-842-2