A review of the Life-Cycle Analysis on Common Plastic Bags
In February 2011, The UK Environment Agency published a report, Life Cycle Analysis on Carrier Bags.
An assessment across all types of carrier bags
- Conventional plastic
- Hydro-biodegradable plastic
- Oxo-biodegradable plastic
- The UK Environment Agency study shows how plastic bags* are the most environmentally friendly.
- If these were banned, it would be worse for the environment as the alternatives to plastic bags have a higher Global Warming Potential.
Click here to read this news article >>
Considerable controversy is attached to the subject of oxo-biodegradability. Even describing this oxidative process as bio-degradable can cause an explosive reaction on the part of hydro-biodegradable technology advocates.
For the one or two readers that are not familiar with the oxo-biodegradable technology let me briefly describe the process.
A masterbatch (additive contained in a pellet of polyolefin) is introduced at the processing stage of a petro-chemical derived plastic material. The inclusion rate is small being 1%. Thus, the impact on processing parameters and finished material properties is negligible.
The additive typically consists of a transition metal salt and stabilisers. The salt has a catalytic action that causes a free radical reaction causing chain cleavage, in turn leading to the creation of hydroperoxides which are precursors to complete bio assimilation –these include esters, alcohols, aldehydes and carboxylic acids. The stabilisers retard this action under the elevated temperatures of processing and in the environment –typically geared to match the required time scale of functionality of the finished packaging item.
There are several papers and test results that confirm the biodegradability of these materials. Click here to read the rest of this news article >>