Absorbent hygiene products (AHPs) – such as baby diapers, incontinence, and menstrual products – are used to absorb human fluids (e.g., urine and blood) through different stages of a human’s life and have become an essential part of our lives.
Over the years, manufacturers have significantly improved the environmental profile of these products and continue to do so; for example, diapers decreased in weight by nearly 50 % within the last few decades (EDANA 2015). Most life cycle assessments (LCAs) found that the major environmental impacts arise from the selection and use of raw materials.
AHPs are made from plastics, pulp, and super absorbent polymers (SAP), and typically become waste after they have been used only once. Different studies have shown that AHPs contribute to approximately 4-10% of municipal solid waste, depending on the country. Since AHPs are currently recycled only to a small extent (<1 %), the main part of this waste is disposed of in landfills and burned in incinerators. LCAs have shown that end-of-life scenarios involving incineration and landfilling contribute to the global warming potential.
An alternative to single-use AHPs exists in the form of reusable products, however, most consumers are not yet willing to use these, as can be seen in the current adoption rates. This is why research on recycling single-use AHPs is so relevant. As such, EDANA, engaged the consultancy Ramboll to carry out a study mapping existing technologies for collecting and recycling AHP waste.
This work was based on both literature reviews and expert interviews. The authors identified 42 global studies and initiatives for AHP collection, separation, and recycling across different stages of development. These studies covered different types of recycling, including mechanical, chemical, and pyrolysis, but also out of the box ideas, such as growing mushrooms or algae on AHP waste.
The authors assessed the weaknesses and strengths of the identified initiatives/technologies and found that none of the studies seemed to be a perfect fit for effectively recycling AHP waste in the near future. For example, many of the examined initiatives are not mature enough to scale, not sufficiently developed to be transferred into a pilot, or lacked economic data for a more accurate assessment. Already established AHP recycling facilities are more promising, but interview partners mentioned low recyclate yields and challenges with wastewater treatment.
The report concluded that collecting and recycling AHP waste is very complex, and that no initiative/technology offers a perfect technically and economically successful solution. This result proves that further investigation and research into AHPs and how to recycle them is needed and that industry engagement is crucial. There are various ongoing projects and business models for both collection and recycling which can be further developed.
The full report is available here.