(a) FFP1 B
(b) FFP2 B
(c) FFP3 B
Figure 4: PF-values against particles in size range of 0.093–1.61 μm for FFP1, FFP2, and FFP3 respirators manufactured by company B. The tests were performed when the FFP respirators were donned on human subjects. Total observations are 30 (30 subjects). The boxplots show the same as in Figure 3. AFF refers to the assigned protection factor for that particular mask.