Filtering facepiece (FFP) respirators (FFRs) are widely used to protect against airborne particles. While conventional FFPs provide no protection against gaseous pollutants, some commercial FFP-type masks now also incorporate small amounts of activated carbon and claim to reduce e.g. odours, nuisance gases or low-level organic vapours. However, such gas protection is rarely documented, and there is currently no standardized test method or certification standard for gas protection in FFP-type respirators.

In this study, the gas protection was evaluated against >100 ppm of cyclohexane for a range of commercially available FFP2- and FFP3-classed masks containing activated carbon from brands including 3M, Honeywell, Dräger, Moldex, and Uvex. Gas adsorption performance varied widely between the models, but was generally limited in terms of both initial protection factor and adsorption capacity. In some cases, activated carbon particles appeared to be fully embedded in binder material, rendering them ineffective. Increased flow rates and elevated humidity further reduced gas adsorption performance. Moisture uptake from exhaled air is particularly detrimental for activated carbon in these devices. This type of condensation can be particularly challenging in cold environments and in masks without exhalation valve. [1]

Overall, the results demonstrate that [...]