Note: The process of degradation may be specified by a prefix or an adjective preceding the term "degradation". For example, degradation caused by the action of water is termed "hydrodegradation" or hydrolysis; by visible or ultraviolet light is termed "photodegradation"; by the action of oxygen or by the combined action of light and oxygen is termed "oxidative degradation" or "photooxidative degradation", respectively; by the action of heat or by the combined effect of chemical agents and heat is termed "thermal degradation" or "thermochemical degradation", respectively; by the combined action of heat and oxygen is termed "thermooxidative degradation".