In the following categories, Abiotic Depletion, Acidification and Eutrophication, the potential impact of the plastic tubular digester was between 1.5- and 7-fold that of the Chinese model (Fig. 2aec). This means that the impact of construction materials was much higher for the tubular digester (i.e. plastic and geomembrane) than for the fixed dome digester (i.e. cement and bricks).