Recycling operators are calling for a standardised labelling system to make it easier to identify recyclable plastics.
They say the move would result in less plastic ending up in landfills, because the public is confused about the variety of symbols currently in use.
Recycling operators say about 20,000 tonnes of plastic are recycled each year, but about three times as much ends up in landfills.
They also say plastic has the potential to be burned cleanly to create energy.
