Due to the fact that no chemical change occurs after a charge-discharge cycle, the pigments theoretically retain their afterglow properties indefinitely. A reduction in light intensity only occurs very slowly, almost imperceptibly. This reduction increases with the degree of coloring of the pigments. Intensely colored types  lose their intensity more quickly than neutral ones. High temperatures of up to several hundred degrees Celsius are not a problem. The only thing that needs to be avoided is prolonged contact with water or high humidity, as this creates a hydroxide layer that negatively affects the light emission intensity.