In just a few months, the face mask has become an indispensable part of our daily lives. However, at the start of the health crisis linked to the COVID-19 pandemic, very few people were using them when taking public transport, working at the office, or walking around in public spaces, hence some bad habits that still persist today.Among the questions regarding wearing a mask that crop up, one of them is central with everyone going back to school or to work: can a disposable mask be used several days in a row?Can a disposable mask be reused?Many people think that a disposable mask is still usable after being washed and dried, but this is totally false. A disposable mask should not be used for more than 3 or 4 hours, after this, it is saturated with moisture, and it then loses its effectiveness and breathability.This limited lifespan is due mainly to the water vapour we exhale when we breathe. FFP2 surgical masks can be used for up to 8 hours, but cannot be reused once you take them off.Cloth masksOnly cloth masks can be washed and reused under specific conditions, as explained by the WHO. According to instructions issued by the organisation, they should be washed in hot water (60°C) with soap or detergent for at least 30 minutes, at least once a day. They can be dried either in the open air or in a tumble dryer.