Quantitative Protection Testing

We performed tests on our DIY Surgical Sterilization Wrap respirators for (1) Particulate Filtration and (2) Face Fit using the PortaCount Plus Model 8020 respirator fit tester. This machine test filters by launching an aerosol at the test filter and measures the number of particulates that get through the filtration substrate.

The particle count is performed using a continuous-flow Condensation Nucleus Counter - a process that grows submicron particles into particles large enough for measurement. This is done by mixing the aerosol with an alcohol vapor so that the alcohol molecules condense into droplets around the molecules of aerosol that have passed through the filtration substrate. The alcohol droplets are then collected on a screen and measured by scattering a laser on the particles and using a photodetector to measure pulses in the incident light - counting pulses counts the number of particles passing through the screen in a given time.

Combining this with a flowrate allows for the calculation of the number of particles per volume. The PortaCount machine is sensitive to particle diameters of 0.02 microns, but cannot distinguish between shapes and structures.

Summaries

Material	Percentage of particles filtered from the air
True HEPA (control)	100.00%
Medline Sterilization Wrap	96.85%
Halyard Surgical Wrap	99.98%

• Excellent filtration seen in Halyard and Medline surgical and sterilization wraps - link
• In a small sample size, the Triton Mask fit individuals better than some N95 masks - link
• Brief testing indicated that some of our DIY masks were performing better or close to N95 masks - link