Abstract: The circular economy model is based on the 4R framework—reduce, reuse, recycle, and recover. While recycling was the primary focus in the past, the shortage of raw materials and the desire to reduce carbon footprints have led to a change in focus: end-of-life materials are now considered resources rather than waste. When discharged, end-of-life materials still possess properties that can
be exploited. For this reason, a comprehensive characterization of reusable materials is mandatory to reduce waste and increase material availability. The reuse of waste materials, such as surgical masks, is of particular interest in giving people in disadvantaged contexts the opportunity to self-produce and self-install panels within their homes, with the dual result of improving indoor comfort and
increasing human capital. This paper focuses on the identification of a possible second application for surgical face masks through experimental characterization. Panels made of masks were tested for water vapor permeability, thermal conductivity, and fire resistance and their use as insulating
material in the building sector was discussed. Based on the results, surgical face masks are suitable as thermal insulating materials, do not pose safety concerns, and can reduce energy consumption and improve thermal comfort when installed indoors.
