Engineering design process of face masks based on circularity and life cycle assessment in the constraint of the covid-19 pandemic

Face masks are currently considered key equipment to protect people against the COVID-19 pandemic. The demand for such devices is considerable, as is the amount of plastic waste generated after their use (approximately 1.6 million tons/day since the outbreak). Even if the sanitary emergency must have the maximum priority, environmental concerns require investigation to find possible mitigation solutions. The aim of this work is to develop an eco-design actions guide that supports the design of dedicated masks, in a manner to reduce the negative impacts of these devices on the environment during the pandemic period. Toward this aim, an environmental assessment based on life cycle assessment and circularity assessment (material circularity indicator) of different types of masks have been carried out on (i) a 3D-printed mask with changeable filters, (ii) a surgical mask, (iii) an FFP2 mask with valve, (iv) an FFP2 mask without valve, and (v) a washable mask. Results highlight how reusable masks (i.e., 3D-printed masks and washable masks) are the most sustainable from a life cycle perspective, drastically reducing the environmental impacts in all categories. The outcomes of the analysis provide a framework to derive a set of eco-design guidelines which have been used to design a new device that couples protection requirements against the virus and environmental sustainability.