Carbon footprint assessment of surgical masks and KN95 respirator masks

Abstract This study aims to investigate the carbon footprint and greenhouse gas emission sources of five typical mask products, including surgical masks and four KN95-grade masks differing in design, from the stage of raw material acquisition to the storage of the mask products. The results show that, for the production of 1000 masks, the carbon footprint of KN95 masks is more than three times larger than that of surgical masks. The carbon footprint of mask raw material production is much larger than that of mask production, with the ear loops being the main contributor to the carbon footprint. The use of each exhalation valve increases the carbon footprint of the mask by approximately 28.14%. In the mask production stage, the carbon footprint of the mask body production process is relatively high. Factors such as equipment mechanism drive, ultrasonic welding, and mask thickness affect the carbon footprint of mask production. Generally, equipment mechanism drive is the largest influencing factor in the carbon footprint of mask production.