The Co-operative Group has become the first supermarket to complete the roll-out of tinted tops across its milk bottles, helping to produce an extra 4,500 tonnes of recyclable plastic every year.

Currently one of the main barriers to use of recycled plastic for milk bottles is discolouration being caused by the caps being mixed in with clear plastic bottles during the recycling process. Tinted caps help to reduce discolouration because they contain a different type of pigment and use less of it than conventional caps.

The new tinted tops will be used across the 202 million bottles of milk The Co-op sells each year.

Protecting the environment remained a key part of The Co-op’s Ethical Plan, said the society’s environmental manager, Iain Ferguson.

“We are proud to be leading the way with this initiative and that The Co-operative is the first retailer to complete this move on all of its own-brand milk bottles,” he said.

Using tinted tops was a “quick win” that could achieve higher recycled content in milk bottles, according to Wrap’s Marcus Gover.