Peterborough city council has apologised for offending residents after thousands of stickers reading “waster” were put on bins as part of a recycling campaign.

Dozens of households said they were insulted by the stickers depicting a red sad-face emoji on their black wheelie bins.

The company behind the scheme also apologised after it emerged the labels were not recyclable.

Bins in the Orton Malborne and Sugar Way areas are part of a trial of 7,000 homes where waste recycling levels will be monitored over six months, with the stickers intended “to help communities think twice about what they could recycle”.

Positive green stickers, which feature a smiling emoji and the word “recycler”, are due to be sent out next week as part of a campaign by the Waste and Resources Action Programme (Wrap), which is supported by the local council.

One person wrote on Twitter: “@WRAP_UK @PeterboroughCC when will you be arranging for the removal of the wasteful and hugely offensive ‘waster’ stickers from bins?”

Another said: “@WRAP_UK thanks for my ‘waster’ sticker plonked on my bin this morning! The whole street has one. Is the sticker recyclable? As an avid recycler I’m miffed!”

More conventional images of a recycling heart and rubbish truck will also be tested in the Castor, Ailsworth and Hampton areas of Peterborough.

In a statement on Facebook, Peterborough city council said: “We apologise to residents for any offence the emoji bin sticker may have caused – and we appreciate we should have communicated better with residents and local councillors.”

A spokesman for Wrap, which manages the Recycle Now campaign in England, added: “Most people in Peterborough recycle; however, there are still improvements that can be made to ensure that all recyclable items are collected. The trial is testing methods which will help residents to remember to put the right things in the right bins.

“It was intended that a green ‘recycle’ sticker with a happy face emoji would be stuck on recycling bins, and the following week a red unhappy ‘waster’ emoji would be stuck on residual waste bins as a reminder to recycle.

“Recycle Now has learnt that there was an operational issue which meant that the stickers went out in the wrong order, and that residents were delivered the red ‘waster’ sticker in the first instance. We understand how this may cause confusion and offence for residents and apologise for this.”