Polypropylene is a plastic polymer, of the chemical designation C3H6. It is used in many different settings, both in industry and in consumer goods. It can be used both as a structural plastic and as a fiber. Like many plastics, polypropylene has virtually endless uses, and its development has not slowed since its discovery. Whether used for industrial molds, rugged currency, car parts, or Tupperware, polypropylene is one of a handful of materials the world is literally built around.
Polypropylene is a byproduct of oil refining. Produced during the process is propylene gas, which, when put into a reactor, becomes propylene powder. After stabilisers are mixed with the powder, it is placed in an extruder, which produces propylene pellets, which can then be turned into a range of things including car bumper bars and food containers. If the pellets are melted, they can be made into a fibre which can then be made into bags.
Buyers are being conned. Your environmentally friendly green bags are made of plastic - polypropylene is a fossil fuel-based plastic. The bags are also imported from China. So, plastic, non-renewable, doing nothing for our balance of payments and guess what? You're paying for the privilege. Supermarkets are laughing all the way to the bank.
A reader wrote to us: "I've just retired after 30 years in the packaging industry and, frankly, I'm amazed at the constant rave about the 'environmental' green bags ... Doesn't anyone realize these bags are made of the same 'almost indestructible' materials used in car bumpers and wheelie bins? ... what happens when these 'cool' bags reach the end of their life cycle? There will be millions of them in circulation, just like plastic bags!