Uncovering Pathways Toward Circular and Low-Carbon Development of PET Plastics for Bottled Water in China by Material Flow and Carbon Footprint Analyses

Polyethylene terephthalate (PET) plastics are widely used in bottled water packaging due to their lightweight and sealing properties, and their additive-free composition significantly facilitates efficient recycling. However, the life-cycle material metabolism and carbon footprint of PET plastics for bottled water in China have not yet been systematically quantified, limiting progress toward sustainable management. In this study, we model the provincial production, consumption, and waste management of PET plastics for bottled water, tracking material flows and carbon footprint from 1997 to 2023. Furthermore, we assess the circulation efficiency of different end-of-life treatment pathways in 2023, along with the associated offsets provided by recycled materials. Our results show that annual production rose from 0.036 to 2.18 million tons (Mt) between 1997 and 2023, which represents a substantial increase in quantity. In 2023, the end-of-life recycling rate reached 97%, with 76% downcycled to chemical fiber and only 5% as the closed-loop “bottle-to-bottle” cycle. In the same year, the life cycle greenhouse gas (GHG) emissions were 6.48 Mt CO2-eq. Under the low-carbon scenario, the life cycle GHG emissions in 2050 remain 59% above the 2024 levels. Therefore, achieving deeper decarbonization will require coupling with additional technologies (adopting biobased plastics and chemical recycling of plastic waste) to meet low-carbon targets. Overall, our findings offer evidence and guidance to advance circular resource use and coordinated carbon footprint reduction in PET plastics for bottled water.