A randomised controlled pilot study to compare filtration factor of a novel non-fit-tested high-efficiency particulate air (HEPA) filtering facemask with a fit-tested N95 mask.

Use of a fit-tested N95 or FFP2 mask is recommended to protect against transmission of airborne pathogens. This poses considerable logistic problems when preparing for, or dealing with, an epidemic. Some of these problems might be overcome by use of a compact reusable high-efficiency particulate air filtering mask that can be cut to size. We carried out a randomised controlled cross-over study to compare the efficacy of such a mask (Totobobo, Dream Lab One Pte Ltd, Singapore) with fit-tested N95 masks (1860 or 1860s or 1862; 3M, St Paul, MN, USA) in 22 healthy volunteers. The median (interquartile range) reduction in airborne particle counts was significantly higher [193-fold (145-200)] for N95 masks than for Totobobo masks [135-fold (83-184)] (P<0.05). There was no statistically significant difference between the proportion of subjects achieving a reduction of > or =100-fold between N95 (19/22) and Totobobo (16/22) masks. We conclude that use of the Totobobo mask without fit testing cannot be recommended, but its performance is sufficiently promising to warrant further investigation.

Protecting staff against airborne viral particles: in vivo efficiency of laser masks.

Laser masks are used to prevent inhalation of viral particles during laser surgery. A crossover trial was performed in eight volunteers to compare the ability of a surgical mask and a laser mask with that of an FFP2 respirator to filter airborne dust particles. The surgical and laser masks were tested when worn normally and when they were taped to the face. The mean reductions in particle counts were 3.0 fold [95% confidence interval (95% CI) 1.8-4.2] for the untaped surgical mask, 3.8 fold (95% CI 2.9-4.6) for the untaped laser mask, 7.5 fold (95% CI 6.5-8.5) for the taped surgical mask, 15.6 fold (95% CI 13.5-17.8) for the taped laser mask, and 102.6 fold (95% CI 41.2-164.1) for the FFP2 half-face respirator. The laser mask provided significantly less protection than the FFP2 respirator (P=0.02), and only marginally more protection than the surgical mask. The continued use of laser masks for respiratory protection is questionable. Taping masks to the face only provided a small improvement in protection.