Aldi milk bottles are being fitted with tags to allow experts to track empties. The retailer is piloting a scheme to track the journey of empty bottles from homes to recycling centres, in a bid to better measure how many arrive for recycling.

As part of an eight-week project with dairy cooperative Arla and tech firm Polytag, selected Aldi bottles will have invisible, fluorescent tags printed on their labels. Once any empties reach recyclers, the tags will be scanned and their arrival recorded.

Aldi and Arla plan to use the data gathered to better understand where the bottles go after they are thrown away. The scheme should also help them gain a more accurate measure of recycling rates.

Customers don’t need to do anything differently and are encouraged to continue recycling as usual.

Luke Emery, Aldi’s plastics and packaging director, said: “This next phase with Polytag represents an exciting step forward in how we use data to drive our sustainability strategy.

“By integrating this advanced traceability technology into our packaging, we can gain deeper insights into the lifecycle of our materials.”

This latest pilot comes after Aldi, Arla and Polytag teamed up for a previous scheme, which used pressure-sensitive labelling.

Polytag’s chief executive, Alice Rackley, said the latest phase showed that UV tagging technology could be used on a larger scale.

She said it offered brands a cost-effective way to obtain more comprehensive information about recycling.

Sun Chemical developed the fluorescent ink used on the labels. Stefaan D’Hoore, its director of business development for speciality inks and coatings, said it was the first commercial use of its fluorescent ink with Polytag’s tech.

The trial will run for eight weeks, after which the companies are expected to assess the recycling data gathered by the tags.