Abstract: There is disclosed the preparation of a degradable polymeric material consisting essentially of an organic polymeric base containing a degradation-promoting amount of a partially degraded organic polymer. The organic polymeric base and the degradation-promoting additive may be derived from the same or different polymers. The invention is especially useful in controlling the environmental deterioration of plastics. The rate of deterioration is a function of the environmental conditions such as light, oxygen, and temperature; the concentration of the additive; and the chemical structure(s) of both the base and the additive.