Table E2.

Particle concentrations measured at 6 cm in front of the mask during the isolation phase of the study.^⁎

Mask	Median	Range	Interquartile Range
N95 mask	−0.13	−52.73–161.29	−15.06–20.22
N95 O2 mask, 2 L/min	−0.83	−58.74–131.36	−11.86–14.05
N95 O2 mask, 10 L/min	3.69	−93.22–91.19	−9.91–18.69
NRM mask, 2 L/min	472.64	11.67–7944.91	82.97–1020.59
NRM mask, 10 L/min	80.81	−22.91–3509.63	24.87–555.24

^⁎The isolation function of each mask was quantified by measuring the external particle concentrations while infusing particles into the mask and expressing each discrete measurement as a percentage of change from the average background concentrations.