Sustainable and safe design of footwear integrating ecological footprint and risk criteria

Highlights: → The ecological footprint (EF) is a suitable screening indicator to assist the assessment of the sustainability of an ecodesign proposal. → The EF does not consider the risk derived from hazardous substances in its evaluation. → Environmental risk assessment (ERA) successfully complemented the evaluation of the EF providing safety criteria. → Options that exceeded the safety limits for Hazard Quotient and Cancer Risk where discarded, thus guaranteeing the protection of children. → Trade-offs among criteria could be established by the application of fuzzy logic techniques to derive an ecodesign index. - Abstract: The ecodesign of a product implies that different potential environmental impacts of diverse nature must be taken into account considering its whole life cycle, apart from the general design criteria (i.e. technical, functional, ergonomic, aesthetic or economic). In this sense, a sustainability assessment methodology, ecological footprint (EF), and environmental risk assessment (ERA), were combined for the first time to derive complementary criteria for the ecodesign of footwear. Four models of children's shoes were analyzed and compared. The synthetic shoes obtained a smaller EF (6.5 gm2) when compared to the leather shoes (11.1 gm2). However, high concentrations of hazardous substances were detected in the former, even making the Hazard Quotient (HQ) and the Cancer Risk (CR) exceed the recommended safety limits for one of the synthetic models analyzed. Risk criteria were prioritized in this case and, consequently, the design proposal was discarded. For the other cases, the perspective provided by the indicators of different nature was balanced to accomplish a fairest evaluation. The selection of fibers produced under sustainable criteria and the reduction of the materials consumption was recommended, since the area requirements would be minimized and the absence of hazardous compounds would ensure safety conditions during the use stage.