Today’s disposable diapers have become an indispensable choice among hygiene products, reflecting in their massive global consumption and waste generation. Most of the diaper waste is neither segregated nor treated and ends up in landfills or incinerators.
Diaper waste valorization has been explored on laboratory- and commercial-scale for years with varying degrees of success. Leading diaper manufacturers such as Procter & Gamble, Kimberley-Clark and Unicharm are making progress to establish a closed-loop recycling of used diapers: recycling of the diaper waste and converting it into new diapers. However, insufficient attention has been paid to the very wide window of possible new products that could be made from the diaper waste. This contribution focuses on the enormous promise of diaper waste, from a perspective of emerging open-loop recycling pathways. The diaper waste was originated from standard disposable diapers which have a fluffy-pulp/superabsorbent polymer weight ratio between 60/40 to 40/60.
In open-loop recycling, the recyclable diaper parts were harnessed and converted into non-diaper products, such as energy pellets, anode material for lithium-ion batteries, concrete admixture, catalysts, soil amendment, mushroom cultivation substrate, etc. Subsequently, several examples of active commercial diaper recycling are discussed to provide a comprehensive blueprint to move the open-loop recycling in a positive direction. The open-loop recycling is a practical strategy to manage diaper waste, rectify the environmental damage brought by the waste and contribute toward circular supply chains.

In this contribution, we summarize the environmental review of standard disposable diapers under three key objectives. Firstly, the segmentation of disposable diapers is presented. Secondly, the environmental impacts in terms of life cycle assessment of standard disposable diapers are discussed. Finally, recent advances on diaper waste extractions are highlighted to enlighten pros and cons of closed-loop and open-loop recycling.