In 2022, Wales mixed fibres from 4.3 tonnes of used nappies into a highway; the waste replaced asphalt material imported from Europe

In 2022, Wales found an unusual use for something most people never think twice about after throwing it away: used nappies. Around 4.3 tonnes of fibres recovered from more than 100,000 nappies were processed and used in resurfacing part of the A487 between Cardigan and Aberystwyth. The material replaced some of the conventional road-making material that would otherwise have been imported from Europe.

The idea was not simply about putting waste into a road. The nappies were cleaned and separated, allowing useful fibres to be recovered instead of sending them straight to landfill.

Wales paved a road with recycled nappies

Nappies are considered single-use plastic products and can remain in landfill for hundreds of years. Wales produces an estimated 143 million discarded nappies each year, making them a significant waste stream even as recycling and collection systems expand.


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The challenge is not simply separating plastic from rubbish. A modern disposable nappy contains an absorbent inner layer designed to hold liquid, alongside plastic and other components. While the plastic lining can be recycled relatively easily, the fibres in the absorbent section have historically been much harder to recover and reuse at scale.

That is where Ammanford-based NappiCycle comes into the project. With support from the Welsh Government's SMART innovation programme, the company has developed a process to clean used nappies and separate their plastic and cellulose fibres. Those recovered materials can then be considered for new applications rather than being treated as waste.

For the A487 trial, fibres recovered from 4.3 tonnes of used nappies have been incorporated into the road surface. The approach gives an otherwise difficult waste material a second role, while allowing engineers to examine how the material behaves inside asphalt.

The other major ingredient, aggregate, was sourced within about 45 miles of the project. Aggregate is the stone and other granular material that provides much of the physical structure of asphalt, so sourcing it close to the road reduced the distance materials needed to travel and helped keep spending within the local economy.

That shorter supply chain is an important part of the experiment. The environmental case for recycling depends not only on keeping waste out of landfill, but also on how much energy and transport are required to collect, process and reuse it. Local sourcing can strengthen the benefits by reducing unnecessary movement of heavy materials.

Wales has a much larger nappy problem to solve

The A487 project comes as Wales expands the collection of absorbent hygiene products. Nappies and similar products are currently collected, or planned for collection, by 15 of Wales's 22 local authorities.

Yet millions of nappies still enter the waste stream each year. The estimated 143 million discarded in Wales illustrates the scale of the opportunity if materials currently treated as rubbish can be recovered and turned into useful products.

The project also reflects a broader change in how waste is being viewed. In a traditional linear system, products are manufactured, used and discarded. A circular economy attempts to keep materials in circulation for as long as possible, finding another use for them instead of continually extracting new resources.

Road construction offers an unusual testing ground for that principle because it consumes large quantities of raw materials. If waste-derived fibres can safely perform a useful function in asphalt, roads could become one potential destination for materials that have previously had few practical recycling options.

There is still an important question to answer before the approach can be considered a proven solution. The A487 scheme is a trial, and the road will undergo rigorous environmental assessments to examine how the recycled material breaks down and behaves over time.

That testing matters because putting a waste material into infrastructure is only useful if it remains safe and performs as intended. The environmental benefits also need to be considered across the material's full life cycle, from collection and cleaning through processing, transport and eventual road maintenance.

From Landfill Nuisance to Global Infrastructure

The Welsh experiment with recycled diapers is far from an isolated marvel; it reflects a growing international effort to turn stubborn domestic waste into lasting infrastructure. In the Netherlands, advanced facilities use high-pressure steam sterilization to separate hygiene products into raw cellulose and plastics, blending them directly into bitumen for road paving. Across Japan, municipal governments employ ozone treatment to deodorize and reclaim diaper fibers, converting them into building filler and industrial components.

In regions where materials are expensive and waste is abundant, engineers are pushing the concept even further. Indonesian researchers recently demonstrated that sanitized diaper fibers could replace up to forty percent of the sand required in concrete walls for low-cost housing. Meanwhile, India has laid over one hundred thousand kilometers of highway using post-consumer plastics mixed with bitumen, proving that flexible waste streams can reliably strengthen major transportation networks.

From one road to a wider circular economy

The Welsh Government sees the scheme as part of a wider effort to develop a circular economy, rather than as an isolated road project. Its broader objective is to find ways of keeping materials in use, reducing waste and creating new economic opportunities around recycling and innovation.

Climate Change Minister Julie James described the approach as part of Wales's push toward a zero-waste economy. She also linked the project to the country's wider recycling ambitions, including the goal of eliminating rubbish sent to landfill after 2025 and ending disposal through energy incineration after 2050.

Economy Minister Vaughan Gething said the project demonstrated how research and development could help Welsh businesses develop solutions to environmental problems while supporting the economy. The involvement of a local company also gives the experiment an economic dimension beyond the road itself.

If the trial passes its environmental assessments and proves technically successful, the concept could eventually be expanded. That could create additional demand for recovered nappy fibres, encourage further investment in processing technology and potentially support green jobs connected with collection, recycling and manufacturing.

Wales already has a strong record in household waste recycling. It ranks first in the UK, second in Europe and third globally, according to the figures supplied by the Welsh Government. Its approach is also shaped by the Well-being of Future Generations Act, which requires public decision-making to consider the effects of today's choices on people who will live with their consequences tomorrow.

The recycled-nappy road therefore represents something larger than an unusual ingredient in asphalt. Its real significance will depend on whether the material can withstand long-term testing and whether the economics make sense at a larger scale. But the trial demonstrates a practical idea at the heart of the circular economy: waste does not necessarily have to remain waste when technology can separate, clean and return its useful parts to the economy.

For Wales, the A487 provides a real-world place to test that principle. A material once designed to be used once and discarded is being given another job, while locally sourced road materials help shorten the supply chain. If the experiment succeeds, the lesson could extend beyond nappies and roads: some of the hardest waste problems may become opportunities when materials are treated as resources rather than something to simply throw away.