5-Chloro-3-((2-hydroxy-1-naphthalenyl)azo)-4-methylbenzenesulfonic acid, calcium salt (2:1) 68189-24-2 Benzenesulfonic acid, 3-chloro-5-((2-hydroxy-1-naphthalenyl)azo)-4-methyl-, calcium salt (2:1) Calcium bis(2-chloro-6-((2-hydroxy-1-naphthyl)azo)toluene-4-sulphonate) EINECS 269-182-9