Highly Time-Resolved and Nontargeted Characterization of Volatile Organic Compound Emissions from Face Masks

Face covering by masks has become a lifeline for humans to prevent the airborne transmission of highly infectious SARS-CoV-2. One of the side effects, however, is the release of volatile organic compounds (VOCs), which can hardly be fully understood based on traditional offline measurements. Here, for the first time, we performed highly time-resolved and nontargeted measurements of VOCs emitted from face masks using an ultrasensitive proton transfer-reaction quadrupole-interface time-of-flight mass spectrometer. We found diverse VOC species, some of which are toxic. The chemical structures of the major VOC species were identified to be from the chemicals and processes involved in mask production. High concentrations of VOCs emitted from surgical masks (predominant mask type) were all concentrated in the initial 1 h and then dropped rapidly to an acceptable level after a process of naturally airing out. Higher emissions from a surgical mask for children are likely due to their colorful cartoon patterns. Despite the lowest emissions, the N95 respirator with an active carbon layer required 6 h to remove the toxic methanol. We support mask wearing to curtail the COVID-19 pandemic, but our results highlight the importance of naturally airing out masks to reduce zero-distance inhalation of mask-emitted VOCs.