Oxo degradable vs oxo biodegradable plastic

 By: MICHAEL STEPHEN

 Published on April 25^th 2022 in Bioplastics News                 

 

At last people are beginning to realise that there is a difference between oxo degradable vs biodegradable plastic!

The Consumer Goods Forum have published their nine “Golden Design Rules” for optimal plastic design, production and recycling.

Rule 2 is headed “Remove Problematic Elements from Packaging” and they include oxo-degradable plastic in their problematic elements.

However, they make it clear that “This rule does not apply to oxo-biodegradable plastics”.

To quote the CGF’s Plastic Waste Coalition of Action:

“This ele­ment of Golden Design Rule 2 applies to all oxo-degradable plastics as defined by CEN, the European Standards autho­rity, unless use is required by law.”

“Oxo-degradation” is defined by CEN in TR15351 as “degradation identified as resulting from oxidative cleavage of macromolecules.” This describes ordinary plastics, which abiotically degrade by oxidation in the open environment and create microplastics, but do not become biodegradable except over a very long period of time. They can be recycled, but cannot be composted.

By contrast, “oxo-biodegradation is defined by CEN as ‘degradation resulting from oxidative and cell-mediated phenomena, either simultaneously or successively’.” This means that the plastic degrades by oxidation until its molecular weight is low enough to be accessible to bacteria and fungi, who then recycle it back into nature. These plastics are tested for degradation, biodegradation, and ecotoxicity according to ASTM D6954.

The Consumer Goods Forum are right to exclude oxo-biodegradable plastics from their list of problematic plastics. The European Chemicals Agency has studied them and found no evidence that they create microplastics; they have been proved by the three-year Oxomar study to biodegrade even in the marine environment; and they can be recycled at scale with no need for separation. They are not designed for composting.