Molecular formula: Ca(ClO)2, CaCl2·Ca(OCl)2·2H2O (often containing impurities such as Ca(OH)2, CaCl2, Ca(ClO2)2 and Cl2). Molecular weight: 142.99 Health hazard: dust may irritate conjunctiva and respiratory tract and cause tooth damage. Skin contact may cause moderate to severe skin damage and irritation.