Fit testing of KN95 masks


  • Janice Campos Caoili Makati Medical Center
  • Arvee Vega Makati Medical Center
  • Sigrid Santos
  • Jomar Bigalbal Makati Medical Center
  • Rosemarie Cabujat Makati Medical Center



COVID-19, personal protective equipment, respiratory protective devices, Philippines


Twenty-six healthcare workers (HCWs) underwent qualitative fit testing for donated KN95 masks. For each fit test episode, the result was either passed or failed. Results for a total of 42 fit test episodes were observed. A result of failed was recorded for 39 of 42 fit test episodes. Various adjustments such as tightening the ear loops to produce a better fit, placing a surgical mask either under or over the KN95 mask, and wearing the K95 mask with a coverall, were done but the result of testing was failed. As fit testing all HCWs in the hospital would be excessively time-consuming, the findings of this fit-testing study served as the basis for a hospital memorandum stating that KN95 masks are not generally recommended for use by HCWs while performing aerosol-generating procedures in the COVID-19 units. HCWs who might use KN95 masks while performing aerosol-generating procedures should first undergo fit-testing to ensure that a good seal is achieved for protection against infectious aerosols.


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Author Biographies

Arvee Vega, Makati Medical Center

Infection Control Officer

Sigrid Santos

Infection Control Officer

Jomar Bigalbal, Makati Medical Center

OSH Officer

Rosemarie Cabujat, Makati Medical Center

Employee Wellbeing Clinic Head




How to Cite

Caoili, J. C., Vega, A., Santos, S., Bigalbal, J., & Cabujat, R. (2020). Fit testing of KN95 masks. International Journal of Infection Control, 16(2).



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