Applying behavioural science to reduce plastic waste from diapers: a mixed-methods study

Disposable absorbent hygiene products, particularly diapers, are a major contributor to global plastic waste. Focusing on high-priority strategies within the EU's waste hierarchy, waste prevention and reuse, we examine two behaviours that reduce reliance on single-use diapers: earlier toilet training and reusable diaper use. We identified behavioural patterning, influencing factors and support for interventions using a mixed-methods study of UK parents (surveys: n = 624; interviews: n = 35), underpinned by behavioural science frameworks (COM-B model, Behaviour Change Wheel). Reusable diapering remains a minority practice, with few users using them exclusively (10% of reusable users) and most combining with disposable diapers. Reusable diaper use was associated with earlier toilet training (χ2(1, N = 322) = 4.05, p = .044). While parents intend to begin toilet training by 30 months, our findings show that completion often occurs significantly later, highlighting a gap between intended and actual timelines (χ2(18, N = 624) = 72.80, p < .001). Barriers and enablers to both behaviours were identified across Capability (e.g., laundry demands, identifying readiness), Opportunity (e.g., product access, childcare support), and Motivation (e.g., environmental values, competing priorities). Recommended interventions include expert-led training, public awareness campaigns, reusable diaper provision and laundering schemes, and flexible work policies. Regulatory measures (e.g., diaper taxes, nursery admission policies) were less favoured. Creating supportive, resource-rich settings at key parenting stages, such as ante- and postnatal periods and early toddlerhood, can empower parents to adopt reusable diapers and earlier toilet training, aligning caregiving with broader sustainability goals of reducing plastic waste.