While plastics do break down in the environment, estimates of the environmental lifetimes of plastic products have only recently been made. These estimates vary widely and range from months to decades or longer. Biotic and abiotic processes act to fragment, degrade, transform, modify, assimilate, and mineralize plastics. The efficiency and selectivity of these processes depend on environmental conditions, the type of plastic, and the functionality and geometry of the product, i.e., on features of product design. Thus, an opportunity exists to consider environmental breakdown in the design of plastic products. Because some plastic products will inevitably enter the environment as pollution, regardless of waste management strategies, it is necessary to confront their persistence.