Introduction: The poor fit of respiratory face masks was a contributing factor to infec-tion during the COVID-19 pandemic. As there is no sizing system for FFP2 face masks according to the relevant European standard, product sizes can vary unpre-dictably. This circumstance has made it difficult to select tight-fitting face masks, par-ticularly for people with smaller, narrower faces. Objective: To investigate the actual size range of low-cost vertical flat-fold face masks that dominated the market during the COVID-19 pandemic and beyond. Methods: Fifty-two one size products and 19 products with generic sizes (XS-XL) from 58 manufacturers were scanned in two dimensions and digitally measured. Results: The one size products showed a rather narrow size distribution, since they only covered the upper third of the total size range found, thereby corresponding to size L (large). Although the average dimensions of products in generic sizes showed a systematic increase from size XS to XL, the variations observed within each size cat-egory call into question any kind of common database. Conclusion: Given the results presented, it seems unlikely that low-cost one size face masks can effectively cover a wider range of facial dimensions. To improve the selec-tion of tight-fitting FFP2 face masks, either specific sizes should be defined by the relevant standardization bodies or manufacturers should describe the facial dimen-sions of the target group for which their products are intended. At the very least, siz-ing metrics should be provided so that consumers can identify appropriate face masks through repeated testing. Premium products with complex designs and additional seals usually provide the required tight fit over a wide range of facial dimensions, but recent experience has shown that these products are difficult to obtain in times of market shortages.
Abdellaoui et al. (Wed,) studied this question.