Why is black plastic packaging so hard to recycle?

You might have already used black plastic this week without thinking about it – but did you know it almost never gets recycled?

Frequently used by the food-packaging industry, black plastic is cheap and the dark background makes food look more appealing to consumers.

But the optical sorting systems used at many recycling plants can’t pick out the black pigment in the plastic. As a result, much of it remains unsorted and ends up in landfill.

The material is so hard to recycle that some of the UK’s biggest supermarkets have pledged to stop using it in their own product ranges by the end of 2019, with others set to follow by the end of 2020.

While the label on the black plastic package might say it can be recycled, and you might put it in the correct bin, after it reaches the recycling centre it's likely to end up in a landfill.

The chart above shows how Near Infrared (NIR) sorting systems can detect other dyes, but not carbon black.

Plastic waste is polluting our ecosystems. About 8 million tonnes of plastic ends up in the world’s oceans every year.

But despite the growing environmental threat from plastic waste, only 14% of plastic packaging worldwide is collected for recycling.

Greenpeace says changing recycling systems to detect black plastic would take “a lot of time and money.” It argues a simpler solution would be for the UK government to ban the use of “problem plastics,” including black plastic, PVC and expanded polystyrene.

“They’re outdated, hazardous and easily replaceable with better alternatives,” the organization says on its website.