The EU’s Single Use Plastics Directive prohibits the placing on the market of single-use plastic products made from oxodegradable plastic, and the coalition is calling on the UK to maintain this regulation as it leaves the EU. The letter cites evidence from Defra and the EU refuting the claim that oxodegradable additives can transform polyolefin plastics into biodegradable plastics, as they merely accelerate the fragmentation of plastics into microplastics.