Contaminated recycling across Britain is expected to increase by 40% this winter compared to summer, according to new research.

As rain turns cardboard into a ‘wet magnet’ for plastics and other recycling, this ‘sticky cardboard’ problem could see over 5,000 tonnes of plastic find its way into the UK’s paper and card recycling system over the course of the winter.

This comes after record-breaking rainfall already this year, with September being the wettest calendar month since records began nearly two hundred years ago.

The research was commissioned by DS Smith and Jonathan Scott, who works at the sustainable packaging and recycling company’s Kemsley Paper Mill, said: “When materials like paper and cardboard get wet, they ‘stick’ to other items in the recycling mix, like plastics and glass, making it harder to separate materials.

“At the largest paper mill for recycled papers in the UK, we process over a fifth of the paper and cardboard recycled in the UK each year, turning it into new packaging papers that can be used to make boxes and paper bags.

“The mill is a key part of the UK’s circular economy, but it can be affected by the changing seasons. In the worst cases, when contamination is really high, we have to reject paper and card that could have been recycled.”

Even with the rainfall expected this winter, there are actions Brits can take at home to help boost the quality of what they recycle. Scott shares his top five tips for ensuring people are recycling their paper and card as best they can:

Follow your local recycling guidelines

“Due to the various recycling rules in the UK, there isn’t a ‘one size’ fits all approach to keeping your paper and cardboard recycling dry. You should always check the recycling guidelines from your local authority to see how you can do this best.”

Keep your lid on

 “If you have a bin with a lid on it, you should try ensuring that it stays on during the rainy period.  A closed lid goes a long way to help keep your materials clean, dry and enables it to be more easily separated.”

Store your cardboard inside when it rains

“Another key tip is to try keep your paper and cardboard sheltered when it does start to rain. This is particularly helpful if your bin doesn’t have a lid. It won’t be possible for all households, but if you can, consider storing recycling under shelter, such as sheds or garages.”

Leave your recycling to dry if it needs to be washed

“This is only applicable if all your recycling material is collected in one bin, but if you rinse your plastic, glass or tin containers of food or other bits, make sure you leave them to dry before placing them in the recycling bin. By putting them straight in, you could be affecting the quality of the paper and cardboard you’ve already collected.”

Consider using your local recycling centres

“If you’re worried about the paper and cardboard you recycle being exposed to the elements throughout winter, you can take your recycling to the local recycling centre. They will sort the materials themselves meaning it will have a better chance of avoiding contamination.”

Stagnating and sometimes falling recycling rates are an increasingly worrying issue, given that the UK is currently ranked 25th out of 30 European countries for paper and card recycling rates.

While people can take steps to make sure their cardboard recycling stays dry before it is collected, separation of recycling would significantly reduce contamination.

Scott added: "We know that people want to do the right thing when it comes to recycling. However, the UK system doesn’t always make things easy for households. One way that we can solve a lot of these contamination issues is by collecting paper and card separately from other materials, and therefore maximising how much can be recycled effectively and efficiently.