Two mannequins were set up, one to simulate realistic coughing and the other realistic breathing. Transmission was tested with a variety of mask fits. Perfect fit did very well, normal fit did worst but was 40% effective.
I’m curious whether “normal” is meant to simulate a proper OSHA-approved fit, or “how normal people wear masks”. My impression was that the OSHA fit test standard for N95 masks was meant to achieve an extremely high-quality seal—they test with volatile substances, and you fail if you can smell them. (https://www.osha.gov/video/respiratory_protection/fittesting_transcript.html) It seems like the “normal” setting here is probably a lower standard than what an OSHA fit is supposed to achieve, whereas “fully sealed” (with tape) is possibly higher.
Effectiveness of facemasks to reduce exposure hazards for airborne infections among general populations
Two mannequins were set up, one to simulate realistic coughing and the other realistic breathing. Transmission was tested with a variety of mask fits. Perfect fit did very well, normal fit did worst but was 40% effective.
Wrong link, should be https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306645/.
I’m curious whether “normal” is meant to simulate a proper OSHA-approved fit, or “how normal people wear masks”. My impression was that the OSHA fit test standard for N95 masks was meant to achieve an extremely high-quality seal—they test with volatile substances, and you fail if you can smell them. (https://www.osha.gov/video/respiratory_protection/fittesting_transcript.html) It seems like the “normal” setting here is probably a lower standard than what an OSHA fit is supposed to achieve, whereas “fully sealed” (with tape) is possibly higher.
Fixed, thank you.