User experiences with food storage in a meatsafe (mesh-covered food storage cabinet) in an informal settlement in Dhaka, Bangladesh

Background Food hygiene is a critical but underemphasized link in fecal–oral disease transmission in dense informal settlements. A mesh-walled meatsafe, designed to exclude insects, animals, and young children while allowing ventilation, was distributed in a randomized controlled trial in Korail, Dhaka. Despite near-universal use (87.7–99.2% of intervention households storing cooked food across five spot-check rounds), the trial detected no reductions in food contamination or child diarrhoea. This qualitative substudy investigated what technological, psychosocial, and contextual factors limited the meatsafe’s protective potential despite high observed use. Methods Guided by the Integrated Behavioral Model for Water, Sanitation, and Hygiene (IBM-WASH), we conducted 16 in-depth interviews with primary caregivers, purposively sampled to capture variation in meatsafe condition, maintenance, and food contamination profiles, and triangulated findings against spot-check records. Transcripts were thematically coded across IBM-WASH domains. Results Barriers preventing correct device use (fidelity barriers) included a steam-spoilage belief leading caregivers to cool food uncovered before meatsafe placement, rexine liner warping reinforcing cooling delays, and cumulative hardware friction from frame instability, latch weakness, and size constraints. Barriers that operated outside the scope of the intervention (beyond-fidelity barriers) included energy scarcity enforcing batch cooking with extended storage, monsoon flooding contaminating cooking spaces, seasonal displacement disrupting routines, and contested childcare authority limiting maternal protective behavior. The uncovered cooling period was invisible to spot-check monitoring yet represented the highest-risk contamination window. Conclusions Near-universal meatsafe use without contamination reductions is explained by a behavioral gap invisible to spot-check monitoring: households stored food only after an uncovered cooling period. The meatsafe addressed only one F-diagram pathway; other fecal–oral routes remained uncontrolled. Sustainable reduction of foodborne enteric disease requires co-designed hardware addressing the full causal pathway, behavior change communication directly confronting the steam-spoilage belief, and concurrent structural investment in energy access, drainage, and pest control.