Yale University and ozone solutions that disinfect N95 medical masks
Document on ozone disinfection of medical masks N95 - Preliminary results [PROJECT] Situation: there is a shortage of personal protective equipment (PPE) for health workers. Background: CDC recognized the need to extend and reuse PPE to protect healthcare workers and establish these standards for N95 disinfection methods - the method must be effective in killing dangerous organisms, not damaging the function of PPE, and not being dangerous to healthcare workers who will reuse PPE. Action: -Evaluation of death efficacy: the effectiveness of ozone disinfection of three different N95 masks commonly used in hospitals during this pandemic (3M 1860, 3M 1870 and 3M 8000 masks) was measured. The masks were contaminated with the Pseudomonas aeruginosa bacteria. Tests done at Yale University (New Haven, CT). - Effect of ozone on mask function: the masks were exposed to 10 cycles of ozone treatment. The effect of ozone on mask function was tested with standard filtration efficiency tests used in NIOSH N95, 42 CFR Part 84 (Respiratory Protection Devices) in an 8130A "Automated Filter Tester" (TSI, Inc.). Exposure to ozone was made in Iowa, USA. Filtration efficiency and pressure drop tests were performed by 4C Air (California, USA).
- Elimination efficiency tests: ozone eliminated 99.9% or more of bacteria from N95 masks. Conditions: 400 ppm for 2 hours at 80% humidity
- Effect of ozone on the function of the mask: there is no significant decrease in the filtration efficiency of the N95 mask after 10 cycles of ozone treatment.
Conditions: 450 ppm (50 ppm more than death test) for 2 hours at 80% humidity
-Safety: the ozone was delivered in an airtight chamber to prevent leaks in the surroundings. Ozone levels were measured with a built-in analyzer.
At the end of the treatment, the ozone was destroyed using a catalyst.
Bottom Line: Ozone is an effective standalone technology for killing bacteria in contaminated N95 masks and presents a low risk to healthcare workers when used in professionally constructed sealed chamber devices with ozone monitoring equipment.
Tests are underway to assess the full extent of ozone's effectiveness in killing bacteria and viruses. It is estimated that ozone in the above conditions can kill 99.9999% of bacteria and viruses in N95 masks. More details are being compiled and will be released soon.
Edward P. Manning, M.D.-Ph.D;. Lokesh Sharma, Ph.D .; Sylvie Dufresne, Ph.D .; Sannel Patel; Kevin M. York; Jimmy Moler; Chirnomas Munroe; Bruce Silver, DDS; Zach Gerbarg, M.D., Pat Gerbarg, M.D. Matthew D. Stephens, Ph.D.