Annually, 3 billion nappies are discarded in the UK, highly polluting with 78% incinerated (releasing CO2) and 22% landfilled (releasing methane over 500 years), and leaking microplastics into oceans and soil. Their environmental impact amounts to 361,000 metric tonnes of CO2eq yearly, equivalent to burning nearly 1 million oil-barrels. Particularly in the UK, consumers are demanding biobased and biodegradable nappies to address this crisis(6). This is a growing trend in the UK, US and EU, as consumers are becoming more cognizant of their waste and the worsening impact of climate change and plastic pollution(6). Through market research conversations with nappy brands and nappy manufacturers, they communicated that they are facing pressure from consumers and regulators, but there are no commercially available biobased and biodegradable parts, an unmet need in the massive £39.8 billion global nappy industry, with £844 million in the UK alone. A nappy is made of 14 parts, with the most important being the superabsorbent polymer (SAP), which absorbs and holds liquids even under pressure. Planet Smart has developed a novel biobased SAP, PlanetSorb and identified biobased commercial sources of the remaining nappy parts. To address the need for biobased and biodegradable nappy parts, particularly the SAP, for which there is currently no commercially available solution, we propose to show the feasibility of incorporating an additive to biodegrade in home composting conditions PlanetSorb as well as the combination of the additional 13 materials required to produce fully biodegradable nappies. Although sustainable nappy brands have had a 15.4% sales increase YoY '20-'21, the current technologies on the market are not sufficient. Some brands in the UK use biobased parts, but are only 78-80% biodegradable and leak microplastics as they still include fossil-based SAP and elastics. For the superabsorbent polymer, innovators in Israel and the US, despite collectively raising $48.4m since 2014, face challenges, the tradeoffs between being completely biobased, biodegradable, and economically scalable are too high for the market. The output of this project would prove that PlanetSorb is 100% biobased and biodegradable with commercially available feedstock, distinguishing it in the market. Planet Smart is prepared to address the unmet needs of the market, by delivering 100% biobased and biodegradable parts for the nappy industry.