TLDR:

As the number of problems that require mask wearing (including air pollution and COVID-19) grows, masks are increasingly important. Now that masks are all but required, the harmful chemicals that can be released from them must be evaluated. In this study, VOCs generated from various types of masks, including commonly used KF94 disposable masks, were assessed. The types and concentrations of VOCs that humans are likely to be exposed to from these masks under various conditions (i.e., emission time, temperature, and mask types) were calculated and compared. This study demonstrated that disposable masks (KF94) released higher concentrations of TVOCs in comparison to cotton masks, with values of 3730 ± 1331 µg m–3 for KF94 and 268 ± 51.6 µg m–3 for cotton masks. The concentrations of TVOCs in KF94 masks are high enough to pose a concern based on indoor air quality guidelines established by the German Federal Environment Agency. However, when KF94 masks were opened and left undisturbed for 30 min at room temperature, TVOC concentrations significantly decreased to 724 ± 5.86 µg m–3 (a 78.2 ± 9.45% reduction from levels measured immediately upon opening). It is clear that particular attention must be paid to the VOCs associated with the use of KF94 masks their effects on human health. Based on our findings, we suggest that prior to wearing a KF94 mask, each product should be opened and not worn for at least 30 min, thereby reducing TVOC concentrations to levels that will not impair human health.