LONDON - Most of the plastic food containers that householders wash out after use and put in the recycling bin cannot actually be recycled, it has emerged. The mixture of plastics used in many yoghurt pots, ready meal trays and other containers limits the ability of councils to recycle them. The Local Government Association says that only a third can be recycled. The rest get sent to landfill.

Up to 80% of packaging could be made more recyclable, the industry said.

The British Plastics Federation said companies are working to use more recyclable containers and called for a financial incentive for manufacturers to use more recyclable plastics.

According to the LGA analysis, around 525,000 tonnes of plastic pots, tubs and trays are used by households in the UK every year, but only 169,000 tonnes of this waste is capable of being recycled.

It blames producers for using a mix of polymers, some of them poor quality.

The LGA, which represents councils in England and Wales, says the government should consider a ban on low-grade plastics.

The LGA says simple tweaks could make a massive difference, highlighting the case of microwave meals which are often supplied in black plastic material.

Black is the only colour that can’t be easily scanned by recycling machines, meaning that process becomes unnecessarily complicated.

Changing the colour of these items would significantly increase the amount that could be used again.

“It’s almost criminal to think that some of the plastics being used are difficult to recycle, and black plastic is almost impossible to recycle,” Cllr Peter Fleming from the LGA told BBC News.

“The only reason we have black plastic being used by manufacturers is that it makes the food look good.”

When it comes to punnets of fruit and vegetables many are made from up to three different types of plastic, including polystyrene, which can’t be recycled.