Why do swimming pools sometimes smell like chlorine or a chemical compound?

Healthy pools do not smell of chemical compounds. Pool water is often described as smelling like chlorine, but a well-maintained pool shouldn’t smell at all. The smell of pool water does not come from chlorine itself, but rather from chemical compounds called chloramines, which build up in pool water when it is not treated properly.

Chloramines are generated from the combination of two ingredients: (1) the chlorine sanitizers added to sanitize pools, and (2) the perspiration, oils, and urine that enter pools from swimmers’ bodies. Chloramines can be removed using chlorine. “Shock treatment” or “super chlorination” is the practice of adding extra chlorine to swimming pools to destroy ammonia and organic compounds that combine with chlorine to create chloramines.