Disposable and reusable nappies: what do LCA studies tell us?
Comparing the environmental performance of disposable and reusable nappies is more complex than distinguishing single-use products from washable ones. The two options involve different materials, manufacturing processes, transport and end-of-life scenarios. For reusable nappies, washing and drying over many use cycles are particularly important.
In 2021, the Life Cycle Initiative published Single-use nappies and their alternatives: Recommendations from Life Cycle Assessments, a meta-analysis of seven LCA studies from different geographical contexts. Its purpose was to help policymakers interpret the available environmental evidence.
Context changes the results
The performance of reusable nappies depends, among other factors, on the number of uses, washing-machine efficiency, load size, temperature, drying practices and the electricity mix. Long use and efficient washing can improve performance; underfilled cycles, high temperatures and energy-intensive drying can increase impacts.
For disposable nappies, product weight, material quantities and composition, and end-of-life treatment influence results. Lighter product designs can reduce impacts associated with raw-material production. Recycling solutions may offer benefits, but depend on technologies, infrastructure and the economic and social conditions needed for implementation.
There is no universal answer
The meta-analysis emphasises that the relative preference between systems varies with geographical, technological and behavioural conditions. A conclusion reached for one country or washing scenario should not automatically be transferred to another context.
A fair comparison requires an equivalent functional unit—for example, the nappy service provided over a defined period—and transparent assumptions about absorbency, leakage, number of uses, washing, energy, water and end of life.
What can an LCA comparison tell us?
LCA is not simply a way to declare one product category the winner. It helps identify the factors that most influence performance and the improvement opportunities in each system. For consumers and policymakers, the key message is to assess actual use and waste-management conditions rather than assume that reusable products are always better or that disposable products perform the same in every context.