I found this plastic shopping bag, which was full of other plastic bags, stored in the bottom of a wardrobe (see photo). Though the bag is labelled as "100% degradable", I wonder why it should start to degrade in the absence of light or moisture, and especially why the red parts should degrade first.
• It looks as though the questioner has an oxo-degradable bag. These bags decompose by oxidation, which can proceed in the absence of sunlight or moisture. A metal, usually manganese or iron, is added to the bag to catalyse the natural oxidation process, which simply chops up the polyalkenes that make up the plastic product into shorter-chain molecules.
But when plastic finds its way into the oceans, this process makes the pollution less obtrusive but still results in a plastic soup of microfragments, typically a couple of millimetres in diameter. Toxins and persistent organic pollutants stick ...
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