N95 respirators for health care workers: the importance of fit, comfort, and usability

Abstract

To be effective in protecting health care staff from coronavirus disease 2019 (COVID19), N95 and P2 respirators must fit correctly1 because the infection can be transmitted by aerosolised particles.2 To achieve an adequate seal, two processes that fulfil similar but different purposes are needed: fit testing and fit checking. Fit testing, a formal component of respiratory protection programs, quantitatively or qualitatively determines which brand, model, and size of respirator provides a proper fit for an individual. Trained operators conduct fit testing, which should be undertaken each time a new brand, type or model, or size of respirator is used, even if someone has previously achieved a proper seal with respirators of the same size, brand, or type. Fit checking should be undertaken each time a respirator is donned to confirm a proper seal, as respirators that have passed fit testing may not provide a proper seal for an individual if incorrectly positioned, if the nose bridge is not properly formed, or if facial hair interferes with the seal. Fit checking training improves the ability of respirator users to achieve proper seals.3