Technical

Are there not still plastic residues after the wrap breaks down?
Once the plastic begins to fragment and accumulate oxygen, the molecular weight decreases (due to the continuous break down of carbon chains in the polymeric structure) and the surface of plastic becomes hydrophilic from its original hydrophobic state, micro-organisms will start using the fragments as food and the only end products remaining are carbon dioxide,
water and biomass, beneficial for soil. Themicrobiologica process continues and in the and the whole original plastic will be consumed by micro-organisms leaving no other toxic residues.

With what level of certainty can the timing of degradation be controlled?
The speed of degradability can largely be controlled by the additive package used for any particular application. The actual speed of degradation, however is affected by the levels of uncontrollable variables, particularly heat, light and stress, to which the plastic is exposed. Higher than planned levels of these will speed up the process and lower levels will slow it down (but no  stop it).

Will biowrap* degradable plastics create methane in a landfill?
No, methane occurs in anaerobic coditions when carbon can only combine with hydrogen. The biowrap* degradation   process is an oxidising process – if no oxygen is present the carbon and hydrogen remains locked in the remnants of the plastic and methane will not be emitted.

* patent applied for