A comparative life cycle assessment of conventional hand dryer and roll paper towel as hand drying methods

A comparative life cycle assessment, under a cradle to gate scope, was carried out between two hand drying methods namely conventional hand dryer use and dispenser issued roll paper towel use. The inventory analysis for this study was aided by the deconstruction of a hand dryer and dispenser unit besides additional data provided by the Physical Resources department, from the product system manufacturers and information from literature. The LCA software SimaPro, supported by the ecoinvent and US-EI databases, was used towards establishing the environmental impacts associated with the lifecycle stages of both the compared product systems. The Impact 2002+ method was used for classification and characterization of these environmental impacts. An uncertainty analysis addressing key input data and assumptions made, a sensitivity analysis covering the use intensity of the product systems and a scenario analysis looking at a US based use phase for the hand dryer were also conducted. Per functional unit, which is to achieve a pair of dried hands, the dispenser product system has a greater life cycle impact than the dryer product system across three of four endpoint impact categories. The use group of lifecycle stages for the dispenser product system, which represents the cradle to gate lifecycle stages associated with the paper towels, constitutes the major portion of this impact. For the dryer product system, the use group of lifecycle stages, which essentially covers the electricity consumption during dryer operation, constitutes the major stake in the impact categories. It is evident from the results of this study that per dry, for a use phase supplied by Ontario's grid (2010 grid mix scenario) and a United States based manufacturing scenario, the use of a conventional hand dryer (rated at 1800 W and under a 30 s use intensity) has a lesser environmental impact than with using two paper towels (100% recycled content, unbleached and weighing 4 g) issued from a roll dispenser. (C) 2015 Elsevier B.V. All rights reserved.