Development and evaluation of an intervention to increase the collection of compostable packaging from households for industrial composting

Certified compostable packaging has the potential to be a more sustainable alternative to some conventional plastics, but only if disposed of appropriately. This study developed and evaluated the effects of a behaviour change intervention on the disposal of compostable packaging in the co-mingled food and garden waste bin for industrial composting in households in the United Kingdom. The intervention targeted barriers to the appropriate disposal of compostable packaging as identified via focus groups, previous research and the capability, opportunity, motivation-behaviour model. Intervention components included front- and back-of-pack labels, tips on positioning of household bins, visual reminders to check packaging labels and which bin to use, and a bag of compost with an infographic highlighting what happens during the composting process. The intervention was delivered over 6 weeks to 120 households who were provided with compostable and non-compostable items. The results from online surveys completed at three time points (pre-intervention, post-intervention and follow-up) and weekly waste audits that assessed the weight of compostable packaging in the food and garden waste bin showed significant increases in perceived capability, opportunity and motivation to correctly dispose of compostable packaging via the food and garden waste bin over the course of the intervention and increased amounts of compostable packaging disposed of. The implications are that standardised, clear labels on industrially compostable packaging are needed to help residents to identify and appropriately dispose of this packaging. Strategies that automatically prompt which bin to use and increase residents' awareness and motivation to appropriately dispose of compostable packaging are also recommended.