active oxygen barrier compositions and articles made therefrom based on poly , preferably poly , a polymer derived from lactic acid , also known as 2 - hydroxy propionic acid , and a transition metal . this active barrier composition , which has been found to consume oxygen , can be utilized in monolithic and multilayer packaging articles , such as preforms and containers , for regulating the exposure of oxygen - sensitive products to oxygen and thus maintaining and enhancing the quality and shelf - life of the product . when provided in multilayer structures with adjacent poly layers , the package both consumes oxygen and provides a biodegradable package and / or one that may be included in a recycling stream .