Light, heat, organic matter, and the transition metals nickel, copper and manganese accelerate the rate of decomposition of sodium hypochlorite. The presence of these transition metal ions is known to catalyze the decomposition of liquid sodium hypochlorite, contributing to the loss of sodium hypochlorite strength and the formation of oxygen. Loss of sodium hypochlorite strength means more product will be needed when the sodium hypochlorite is used as a disinfectant.
Oxygen build-up can pose problems when storing sodium hypochlorite in storage containers or sodium hypochlorite transport piping due to pressure build-up. By removing suspended solids to nearly undetectable levels from the sodium hypochlorite solution, the rate of decomposition is significantly reduced. In addition, the formation of oxygen is nearly eliminated, resulting in significantly reducing the rate of decomposition and nearly eliminating the formation of oxygen.
All sodium hypochlorite decomposition is dependent on temperature. For any given temperature, the higher the strength, the faster it decomposes and the higher the level of oxygen and chlorate formation. In summary, for every 10° C increase in storage temperature, the sodium hypochlorite will decompose at an increased rate factor of approximately 3.5.