“In this study, VOCs [volatile organic compounds] 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…

It is clear that particular attention must be paid to the VOCs associated with the use of KF94 masks their effects on human health.”