How sustainable and safe is drinking from refill-and-reuse bottles? An analysis based on life-cycle assessment (LCA)...

In response to the pressing issue of plastic waste, individuals are increasingly choosing environmentally sustainable packaging alternatives to cope with plastic waste, a trend that is significantly impacting the drinking water industry. Using life cycle assessment (LCA), this study calculated the environmental impact of the production and 1-year use of 1000-mL refillable bottles of different materials (aluminium, glass, high-density polyethylene (HDPE), and stainless steel) compared with 500-mL polyethylene terephthalate (PET) bottle for drinking water. Moreover, the microbiological quality of water has been measured over a period of 5 days. Assuming a water consumption out-of-home of 1.0 L/day, it corresponds to 730 single-use PET bottles and 1 refilled-and-reused bottle in 1 year. Additionally, different bottles washing scenarios (no washing, hand washing, low-energy efficient dishwashing, high-energy efficient dishwashing) were included in the life cycle inventory (LCI). The main results indicate that, when considering production alone, 1 PET bottle is the least impactful (GWP = 0.0925 ± 0.0002 kg CO₂ eq.) compared to 1 bottle of all other materials (GWP from 0.2831 kg CO2 eq. of HDPE bottle to 13.1035 kg CO₂ eq. of aluminium bottle). However, when switching over the functional unit of "1-year-of-use", the impact of refillable bottles production becomes negligible independently on the material, whereas single-use PET bottles impact dramatically increased to GWP = 67.54 ± 0.14 kg CO₂ eq. Reusable bottles' impact on annual use is mainly determined by the washing method. In particular, we have demonstrated that dishwashing proves to be optimal for ensuring low environmental impact and substantial reduction of microbial charge (about 90 % for all dishwashed bottles) compared with no washing.