2-Naphthalenecarboxylic acid, 4-((3-chloro-2-ethyl-5-sulfophenyl)azo)-3-hydroxy-, calcium salt (1:1) 67892-49-3 Calcium 4-((3-chloro-2-ethyl-5-sulphonatophenyl)azo)-3-hydroxy-2-naphthoate EINECS 267-582-8