From Mr N. B. Vogt

It is correct, as David Lindsay points out, that there is a European Composting Standard EN 13432, but there are at least two types of biodegradable plastic.

The EN 13432 defines that packaging must biodegrade 90 per cent within 180 days (the equivalent US Standard ASTM D6400 requires 60 per cent). This is very suitable for many bioplastics/biopolymers (plastics made from bio-materials) and these are therefore, as pr. the definition in the standard “compostable”.

The other type of biodegradable plastics is conventional plastic to which is added small amounts of oxo-biodegradable additives. These additives make the conventional plastic oxidate so they degrade within months in the environment or in a landfill.

The oxo-degraded plastic is then biodegraded by micro organisms in the same way as bio-material plastics, as has been shown, using standards such as ASTM D5338 (standard test method for determining aerobic biodegradation of plastic materials under controlled composting conditions).

Documentation can be found at the Noibeide website (www.noibeide.com). Unfortunately, there is little knowledge about the pros and cons of the opportunities of the different plastics. This is not only in Malta, but also worldwide.

Having said this to clarify and bring attention to a little thought about opportunity (oxo-biodegradable plastics), I also want to emphasise that composting conventional plastic is probably the least environmental and/or effective way to manage conventional plastic waste.

Conventional plastic has the advantage that it can be reused, recycled, remixed and finally recovered to energy when it is no longer feasible to use it. Conventional plastic is simply energy borrowed in the form of a material. Composting wastes this energy. When it then can be demonstrated that conventional plastic with oxo-biodegradable additives retains all the properties of conventional plastic, including a very much lower price tag compared to most bio-plastics, and can be made to oxo-biodegrade if misplaced, then it may be seen as appropriate that a tax on bags should encourage i) less unnecessary use of plastic and/or ii) a shift to address the challenge of non-biodegradable plastic overall.

Nils B. Vogt

Siamalgamate Co. Ltd

THAILAND