[4] Tennant's process is essentially still used today,[4][3] and became of military importance during World War I, because calcium hypochlorite was the active ingredient in trench disinfectant.

[4] Calcium hypochlorite is commonly used to sanitize public swimming pools and disinfect drinking water.

[8] Calcium hypochlorite can be used to oxidize thiol and sulfide byproducts in organic synthesis and thereby reduce their odour and make them safe to dispose of.

[11][12] Calcium hypochlorite reacts rapidly with acids producing calcium chloride, chlorine gas, and water:[citation needed] It is a strong oxidizing agent, as it contains a hypochlorite ion at the valence +1 (redox state: Cl+1).

[citation needed] Calcium hypochlorite should not be stored wet and hot, or near any acid, organic materials, or metals.