15958-19-7 67990-35-6 Benzenesulfonic acid, 5-chloro-2-((2-hydroxy-1-naphthalenyl)azo)-4-methyl, calcium salt (2:1) Benzenesulfonic acid, 5-chloro-2-((2-hydroxy-1-naphthalenyl)azo)-4-methyl-, calcium salt (2:1) Calcium bis(2-chloro-5-((2-hydroxy-1-naphthyl)azo)toluene-4-sulphonate) EINECS 268-057-6