Calcium Hypochlorit (CAPO) is an inorganic compound with formula Ca(ClO)₂. It is a white solid. It strongly smells of chlorine, owing to its slow decomposition in moist air. This compound is relatively stable as a solid and solution and has greater available chlorine than sodium hypochlorite."Pure" samples have 99.2% active chlorine. Given common industrial purity, an active chlorine content of 65-70% is typical.It is the main active ingredient of products called bleaching powder, used for water treatment and as a bleaching agent.