Healthy soil underpins a range of ecosystem services including food production, biodiversity, carbon storage and flood risk mitigation. Addressing contaminants in soil, including microplastic pollution, is vital for protecting and improving soil health. We are working to build an understanding of the impact of microplastics to soil and to develop mitigation capabilities.

The plastic problem is one of management not eradication, to reduce, reuse, and recycle the material we have and not let it escape into, and damage, our environment. We have focused our efforts in tackling the most commonly used and littered plastic items, but we are aware of concerns with the use of agri-plastics too, particularly with single-use types such as mulch films.

We are concerned about the potential for oxo-degradable plastic to release microplastics. In 2021, we published our response to a call for evidence which also covered oxo-degradable plastics. Most respondents objected to their use and supported introducing a ban. A review by the Hazardous Substances Advisory Committee (HSAC) showed there is no environmental benefit to oxo-degradable plastic, and they are likely to be harmful when released into the environment. This year, Defra has commissioned a second HSAC review and are minded to introduce a ban on this material pending evidence from the review.

The UK Government continues to take a cautious approach to biodegradable plastics. The UK standard for biodegradable plastics (EN13432) allows for contaminants in the final output: “no more than 10% contaminants to pass through a 2mm sieve”. This means that microplastics less than 2mm could be produced by a biodegradable plastic mulch film that meets the standard and be spread to land. Additionally, while we are not aware of any biodegradable plastic that can reach levels of 100% biodegradation, evidence used to inform the European Union’s legislation around biodegradable plastics in agricultural applications may not apply to the UK. The UK has differing conditions, such as temperatures and humidity levels, which affect biodegradability.

We will continue to review the evidence around both types of plastic to take a systematic approach to reducing the use of unnecessary and harmful single-use plastics.