ABSTRACT
Plastics litter is a by-product of the agricultural industry and plastics with time controlled degradability are widely used in automated agriculture where there is a positive cost benefit. To make plastics inherently biodegradable, then, as in the case of the biopolymer Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is to make them less useful as packaging materials. Consequently in parallel with the approach considerable attention has been paid to the use of additives and in particular, non-toxic transition metal compounds to accelerate photo-oxidation. Household waste is a mixture of all kinds of metallic, ceramic, biological and plastics waste and only the most intensive separation and cleansing procedures can produce mixed plastics of sufficient quality to recycle. How then do degradable plastics fit into the systems approach to waste disposal. This problem of terminology is one which clouds the whole issue of environmental degradation of plastics. The end of the induction period must be accurately controllable by some trigger of the environment.
