Respirators have a higher filtration efficacy than medical masks as defined by standardised specifications. An experimental study showed that, when coughing through the medical face mask or respirator at a distance of 20 cm from a Petri dish, respirators were more effective than medical face masks in limiting the release of infectious respiratory droplets containing SARS-CoV-2 from patients with COVID-19 [63]. Another experimental study applying a cough simulator also showed that respirators were more efficient than medical face masks when worn by the coughing mannequin and when worn by the exposed mannequin [64]. The efficacy was higher when the respirator was worn by the coughing mannequin and when the respirator was tightly fit. Efficacy was also dependent on distance and viral load.
The choice of suitable respirator for the shape of a user’s face (type and size) and training to ensure that the user knows how carry out a pre-use seal check are crucial requirements for respirators to be effective [114]. The seal check should be repeated every time a user dons the respirator. Therefore, due to difficulties to ensure appropriate use and fitting of respirators when used in the community, any possible added value of respirators in preventing respiratory infections is expected to be lower in the community than in healthcare.
