• Question: how are new plastic bags biodegradable

    Asked by maddmatty to Betul, Bridget, Ceri-Wyn, Laurel, Maria on 17 Jun 2010 in Categories: .
    • Photo: Maria Pawlowska

      Maria Pawlowska answered on 16 Jun 2010:

      I love the idea of biodegradable things!! Our planet is a beautiful place and we’re leaving way too much rubbish all over the place. The way the new plastic bags work is that they’re made out of compounds which bacteria can eat so not just plain plastic. And since bacteria are all over the place they’re sure to ear or biodegrade) the bags!

    • Photo: Ceri-Wyn Thomas

      Ceri-Wyn Thomas answered on 16 Jun 2010:

      The structure of the plastic itself is designed to allow microbes to break down and metabolise the polymers over certain temperatures and certain moisture levels. Non-biodegradable plastic can not be broken down in this way. Microbes digest the biodegradable material and produce a form of inert soil-like mulch which is considered less harmful to the environment. However a MUCH better alternative is to use a reusable bag that you don’t throw away or put all your food waste on your compost heap!

      Plastic bags- even biodegradable ones- can wreak havoc to some animals. Plastic bags thrown out to sea as waste (this happens a lot sadly) can be swallowed by turtles and seals who mistake them for jellyfish- they become so full of indigestible plastic they die 🙁 Biodegradable bags wouldn’t help much in these cases since they wouldn’t degrade quickly enough and I don’t think they degrade very quickly in landfill either. It’s better to find alternatives to throwaway plastic bags.

    • Photo: Laurel Fogarty

      Laurel Fogarty answered on 17 Jun 2010:

      They add something to the plastic that allows bacteria to break it down in the right conditions (in landfills for example). They can also make bio-plastic which is made from renewable biomass, not petroleum so that is more biodegradable too.

    • Photo: Bridget Waller

      Bridget Waller answered on 17 Jun 2010:

      Most of them are made of plastic that degrades quicker in the presence of oxygen… so even though they don’t create lots of waste they can still release harmful subtsances into the environment. So there are always pros and cons to environmentally friendly alternatives!

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