Two decades after methyl bromide: Progress, challenges, and innovations for fumigation of stored-product pests

More than two decades after the phase-out of the fumigant methyl bromide as an ozone-depleting gas under the Montreal Protocol, fumigation remains essential for postharvest agriculture and stored-product pest management. No single alternative has entirely replicated the combination of broad-spectrum efficacy, rapid action, penetration, and operational flexibility historically provided by methyl bromide. The loss of methyl bromide continues to shape pest management in grain storage, processing facilities, quarantine systems, and similar structures holding durable postharvest products. This review synthesizes progress and persistent challenges since the phase-out, evaluating registered fumigants, alternative chemistries, and emerging physical and hybrid technologies. Although research output has expanded substantially, translation to field-scale adoption remains slow, constrained by safety and exposure concerns, infrastructure requirements, regulatory fragmentation, and limited incentives for product registrants. We highlight the growing disconnect between laboratory innovation and commercial implementation, identify systems-based approaches as areas of potential promise, and conclude with strategic recommendations for research, regulatory harmonization, public-private collaboration, and workforce development to support the next generation of fumigation technologies and expertise.