Compostable Plastics

Compostable Plastics

In 2018 the UK Plastics Pact set a target to make all plastic packaging 100% recyclable, reusable, or compostable, and to eliminate all unnecessary single-use packaging by 2025. This declaration has resulted in a significant growth of the compostable plastics packaging sector. New companies are offering a vast range of products that are intended to replace single-use plastic packaging in products that are not suited to recycling due to contamination such as nappies, wipes, and take-away food packaging and ready-meal trays. Our own citizen science research showed a strong consumer demand too: 84% of UK households taking part reported that they are more likely to choose products that are marked as "biodegradable" or "compostable". Plastics Europe estimate the global market for biodegradable plastics, which was 1.2 million tonnes in 2018, is set to grow by 60% by 2023. However, compostable plastics need to be disposed of properly if they are to deliver on their environmental promise and in the UK there is currently no system for collection, sorting or processing of compostable plastics. Through a series of industry meetings and site visits with our industrial partners we undertook a systems analysis of compostable packaging. 

Led by Professor Mark Miodownik, with Professor Helen Hailes (UCL Chemistry) Professor John Ward (UCL Biochemical Engineering) and Jenny Bird (Public Policy Manager for UCL STEaPP), and funded by UK Research and Innovation (UKRI) and Natural Environment Research Council (NERC), this 3-year project follows on from Designing-Out Plastic Waste and continues the work of the Plastic Waste Innovation Hub. We aim to unlock the barriers to a sustainable system for the use of compostable plastics in the UK and worldwide. 

Our project objectives: 

  1. Measure the environmental impact and feasibility of processing large volumes of compostable plastics using industrial composting, anaerobic digestion facilities, and home compost facilities. 
  2. Improve the effectiveness of industrial composting of biodegradable plastics by identifying key microbes present and developing suitable innocula to enhance breakdown capabilities. 
  3. Test the effectiveness and feasibility of automatic detection and sorting technologies for compostables within the existing waste collection facilities. 
  4. Investigate the effect of packaging design and labelling on customer behaviour and make an evidence-based recommendation for a UK code of practice. 
  5. Review the current products on the market to understand where compostable packaging could make a positive contribution to the UK and global sustainability targets. 
  6. Assess current European and International standards and make evidence-based policy recommendations for the UK system design and regulation of a circular economy of compostable plastics. 

This research is funded by:

Compostable Plastics Compostable Plastics