Fit-testing vs fit-checking: improving protection against COVID-19

Fit-testing is necessary for better protection against COVID-19 for those susceptible to ill-fitting masks, a study suggestsFit-testing is necessary for better protection against COVID-19 for those susceptible to ill-fitting masks, a study suggests.

The research found that women and Asian healthcare workers could be vulnerable to COVID-19 due to ill-fitting masks.

The review revealed that the mask ‘fit-pass’ rate for females compared with males was 85% and 95%, respectively. Higher initial ‘fit-pass’ rates were reported in Caucasians (90%) compared with Asians (84%).

Furthermore, particularly low rates were reported in Asian females, with an average of 60%.

As a result, the researchers urge that fit-testing is used throughout healthcare settings.

The panel of the report, published in Anaesthesia, was derived, however, from cohort in which females and Asians were underrepresented.

The respirator fit appears more important for airborne protection than the filtration capacity of the material, the authors highlighted.

‘Satisfactory airborne protection will only be provided if the filtering face piece respirators are properly fitted to the individual’s face, providing a tight facial seal,’ explained senior co-author professor Britta von Ungern-Sternberg, from the Perth Children’s Hospital/The University of Western Australia, Perth, Australia.

‘Airborne protection is decreased in the presence of a leak as unfiltered air will be drawn inside the mask.’

‘Fit-checking’ vs ‘fit-testing’ masks

The paper discussed the difference between ‘fit-checking’ and ‘fit-testing.’

In ‘fit-checking’, the healthcare worker checks their own mask has a good facial seal. However, ‘fit-testing’ is a standardised test measuring if a certain mask fits correctly.

The authors said ‘fit-testing’ should form part of official hospital occupational health and safety programmes.

However, COVID-19 highlighted a number of UK medical trusts running ‘short of filtering face piece respirators.’

Trusts are ‘no longer insisting staff have a fit-test before they start wearing a mask while treating infected patients,’ they said.

The best fit

Due to the associated time and costs, some health officials propose the elimination of ‘fit-testing’ and advocate that a ‘fit-check’ is sufficient in determining respirator fit.

However, the US National Institute for Occupational Safety and Health conducted a study that demonstrated protection of N95/FFP2 masks improved from 67% without fit-testing to 96% with fit-testing.

The authors recommend not to use a ‘fit-check’ as a substitute for ‘fit-testing’, to identify the respirator that fits best.


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