After writing about agricultural waste on Monday, I picked up a copy of Farmer's Weekly in a bookstore and noticed an article about biodegradable plastics that can be used as sheets for suppressing weeds, maintaining soil moisture, and other applications, or as bags. A company called Self-Destruct Plastics is selling oxo-biodegradable plastics in South Africa beginning this year. The product can be custom-manufactured to degrade at different rates, depending on the intended application.
As noted by British manufacturer Symphony Environmental, plastics made from crops are subject to the same criticisms levelled at biofuels, notably that they compete with food for land and water.
Degradable plastics are a good idea, but Symphony produces oxo-bio bags made from naptha, a waste product of oil refining which would otherwise be wasted, and no crops are involved in its manufacture. Oxo-bio can be recycled and made from recyclate, but if not recycled it will self-destruct in a short time, leaving no fragments, no methane nor harmful residues. As it is made with the same machinery as normal plastic, oxo-bio has little or no extra cost.
[Update on 14 March 2008: Here's some more research into plastics in South Africa from Engineer Simplicity.]
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