4-Chloro-5-methyl-2-((2-hydroxy-1-naphthyl)azo)-1-benzenesulfonic acid, calcium salt 67801-02-9 Benzenesulfonic acid, 4-chloro-2-((2-hydroxy-1-naphthalenyl)azo)-5-methyl-, calcium salt (2:1) Calcium bis(6-chloro-4-((2-hydroxy-1-naphthyl)azo)toluene-3-sulphonate) EINECS 267-123-1