Earlier toilet training could curb growing diaper waste crisis Lisa Lock Scientific Editor Robert Egan Senior Editor Earlier toilet training and new recycling technologies are among expert-backed solutions to reduce the environmental impact of disposable diapers and other hygiene products, according to a new study led by UCL researchers. The paper, published in Nature Sustainability, sets out a roadmap for changing how absorbent hygiene products (AHPs), which include diapers, incontinence products and period products, are designed, used and disposed of. AHPs account for an estimated 160–200 million metric tons (176–220 million tons) of waste each year globally, with the vast majority sent to landfills or incineration.

In regions without adequate waste collection, used diapers are often dumped or burned, contributing to plastic pollution, contaminated water and the spread of disease. The research team identified three system interventions that they expect will radically reduce the environmental impact of AHPs. They say behavior change around toilet training and greater use of reusable products can reduce product use; new and scalable recycling technologies will promote a more circular system; and developing completely compostable products can divert products from landfills and incineration to produce compost or biogas.

Dr. Elze Porte, senior research fellow at UCL Mechanical Engineering and lead author of the study, said, "More than 300,000 diapers are thrown away globally every minute. In the U.K.

alone, around 14 million people experience incontinence, many of whom use disposable incontinence products. This makes absorbent hygiene products a major, yet largely unrecognized, contributor to the plastic waste crisis. "These products are essential for health, dignity and caregiving, but their environmental impact has largely gone under the radar.

What our research shows is that this is not a problem with a single solution. It requires coordinated changes across behavior, technology, materials and policy." Reducing use at the source The first intervention recommended by the authors is reducing and reusing, encouraging earlier toilet training and greater uptake of reusable diapers. They note that earlier toilet training may also benefit children's bladder and bowel health.

The study recognizes that changes to diaper use carry challenges because of a lack of guidance, time pressures on caregivers and the perceived convenience of disposable products. It calls for better support for families, including clearer guidance from health care providers and changes to workplace and child care systems that make lower-waste practices more feasible. Recycling around contamination challenges Second, greater emphasis on technologies for recycling AHPs is needed because of disposable diapers' complex mix of plastics, fibers and superabsorbent materials, combined with contamination from human waste and medicines.

While a small number of recycling technologies exist, most recover only part of the materials. The researchers recommend developing recycling methods that can recover all diaper materials on a large scale, as well as better decontamination technologies to remove pathogens and medicine residues from used products.