Baby Diaper Waste: a growing problem with no simple solutions

In 2021 the United Nations reported that disposable diapers are one of the biggest contributors to plastic waste globally. Every minute around the world over 300,000 disposable nappies/diapers enter landfills, incineration or pollute the environment including our oceans. In the EU alone, it is estimated that 33 billion single-use nappies/diapers are consumed every year, resulting in around 6.7 million tonnes of waste annually. And globally the numbers are only expected to grow due to improving economies, urbanisation, increased availability and marketing, and a growing global population.  

There is mounting evidence of the negative effects of plastic waste on human health, the environment and economies globally, with some island nations and low-income urban centres disproportionally affected. The island nation of Vanuatu for example is considering the ban of disposable diaper waste after it was revealed that nappies/diapers account for nearly a third of the nation's solid waste. 

There are no simple solutions to dealing with disposable diaper waste. They typically contain a mix of wood pulp and plastics including amazing materials such as superabsorbent polymers (SAPs). These SAPs absorb 300% their weight in urine, puffing up as they do, and stopping it from leaking out or making a child’s skin wet. They are one of the reasons why disposable diaper technology has improved so much over the last few decades. Once used, these different materials together with human pathogens are wrapped up in more plastic and swiftly binned. At processing waste plants this mixed plastic waste is difficult and expensive to separate. So most of it ends up in landfills or incinerated contributing to greenhouse gas emissions and climate change. Untreated plastic waste also ends up in our soil, water and oceans and is linked to destruction of eco systems and marine life. 

“Dirty nappies (diapers) could be considered the most harmful item of marine litter” Jo Royle Director of Common Seas & Advisory 
 

Our research team at UCL is analysing four way to address this problem - reduce, reuse, recycling and composting, to understand how best we can begin to address the issues. Whilst challenges exist with all models, one of our early findings when looking at the growing use numbers was that in many high income countries the average toilet training age of children increased from 28 months in the 1950s to 37 months by the 2000s. This means that the number of disposable diapers per child has increased high income, though the root causes of this increase are not clear. But it noteworthy that in lower and middle income countries toilet training ages are typically lower, some achieving continence at 12 months. Thus, the Big Toilet Project is the first global attempt to understand people’s practices for toilet training children, to understand the root causes and inform future strategies that work for parents, children and the environment.

For more information about diaper waste refer to Life Cycle Initiative hosted by the United Nations Environment Programme here and the Ellen Macarthur Foundation here. 

We are also actively researching ways to more effectively reuse, recycle and compost diapers, please contact us for more information about this work.