Comments on biodegradable plastics (besides compostable)

Biodegradation in open environments:

EUBP would like to stress that biodegradation in the open environment is not a waste management option. In order to claim a product’s biodegradability, the ambient conditions must be specified, and a timeframe for biodegradation must be set to make claims measurable and comparable. This is regulated in applicable standards. Biodegradability in the open environment (especially marine) is “desirable” only for very few, highly specific, applications. These could be applications that would be difficult to find and recover, such as firework casings, or applications intended to be used by professionals (e.g., farmers or fishermen/fisherwomen) under specific circumstances.

Therefore, we strongly advise that biodegradation should be regarded as a ‘system property’ only insofar, as it refers to the intended receiving environment. The mere eventuality that a plastic application – or small parts of it – may, in rare cases, end up in a different environment, does not justify overly burdensome biodegradation requirements. Or else, such requirements would have to apply to all other materials, too.

Biodegradation in soil without generating microplastics:

Biodegradable polymers have the advantage that they do not erode into persistent secondary microplastics upon degradation, because  natural environments habit microbes that are able to metabolise these polymers. The residence time is considerably lower for biodegradable polymers compared to conventional plastic materials. Therefore, biodegradable plastics can help in minimizing environmental impacts, while reducing the accumulation of plastic particles in different environmental habitats. I.e., industrially compostable plastics significantly reduce the amount of persistent non-biodegradable microplastics in the compost and thus a subsequent leakage into the environment. Soil-biodegradable mulch films help to stop leakage and accumulation of persistent microplastics in agricultural soils.

EUBP supports efforts to gain a better understanding of the origin and creation of microplastics and their release into and effect on the environment, to minimise environmental impacts. There is no evidence of a greater dispersion of biodegradable or compostable plastic products in the environment than any other materials (glass, paper, metal, etc.). The risk for any (plastic) material to be transferred (by wind or runoff) from one (