Validation of respirator fit testing for emergency workers during simulated life support tasks – project summary

Status: In progress


This is an experimental study where we aim to compare respiratory fit with two protocols: i) the Canadian Standards Association (CSA) standard fit testing protocol and ii) a simulated work fit testing protocol using a set of paramedic tasks. We also aim to identify factors associated with passing a standard and simulated respirator fit test.


Paramedics provide emergency care to patients who may have infectious diseases. Often care is provided in uncontrolled environments or in enclosed spaces (i.e., in the ambulance) with little ventilation putting them at risk of becoming exposed. Paramedics may also provide treatments that can cause aerosols to be generated from patients such as chest compressions or putting a tube in a patient’s airway. This can increase the chance that infectious bioaerosol material is in the air they breathe. Respirators are often the only way paramedics can protect themselves from being exposed to these bioaerosols due to their unpredictable work environment. Therefore, effective respiratory protection is vital in preventing paramedics from contracting airborne infectious diseases.

Paramedic tasks involving patient handling and life support can cause paramedics to move their body into awkward postures. Awkward postures or movements can increase the chance that the seal between the respirator and face is broken. Breaking the seal of the respirator increases the chance of the paramedic being exposed to infectious bioaerosol material in the air. The current respiratory fit testing protocols that decide if a respirator will protect someone or not may not adequately represent the movements paramedics do during their job tasks, putting them at risk of being exposed to infectious bioaerosols. To test this, we plan to conduct an experimental study to measure the fit of respirators during simulated paramedic tasks and compare the results to the standard fit testing protocol.


We aim to recruit 200 working paramedics in Ontario through paramedic organizations, posters, social media campaigns, and an ongoing COVID-19 paramedic study. Recruited paramedics will have anthropometric (e.g., facial dimensions, height, and wrist circumference) and physiological (e.g., heart rate, blood pressure, and oxygen saturation) measurements taken, and complete a questionnaire about themselves and experiences with respirators.  Respiratory fit testing using two different protocols: the CSA standard protocol and a modified protocol will be conducted.

The standard protocol includes the recommended set of exercises (e.g., talking, moving head side-to-side) developed by the CSA Group. This protocol is used for all workplaces requiring the use of respirators in Ontario. The modified protocol consists of a set of exercises that mimic life support and patient handling tasks (e.g., lifting a patient off floor onto stretcher, loading/unloading stretchers into ambulance) and life support tasks (e.g. compressions on the floor) that are thought to put paramedics at risk of breaking the seal of their respirator.

Paramedics will repeat the fit testing protocols on three different types of respirators that are used by paramedic services across Ontario, including disposable N95 face filtering masks, half -face elastomeric respirators, full-face elastomeric respirators, and/or powered air purifying respirators. Respirator fit will be measured using a fit tester that generates a fit test score by comparing the number of particles inside the mask compared to outside the mask. The fit testing scores, and the number of paramedics who “pass” the fit test, will be compared between the standard and modified protocols for the respirators. Factors that influence who passes a fit test will also be investigated.  


Given the concerns surrounding the spread of respiratory diseases like COVID-19, it is imperative the fit testing standard correctly assigns a pass for respiratory fit for Ontario’s paramedics. This study will identify paramedic tasks that may compromise the fit of respirators (i.e., break the seal between the respirator and face) and provide evidence on what level of respiratory protection is needed to provide adequate respiratory protection for paramedic work.

These findings may inform future policy changes to i) respiratory protection requirements when treating potentially infectious patients during emergency care and to ii) respiratory fit testing protocols for paramedics. Changes would improve health and safety measures for paramedics and reduce workplace infections and claims.


This project is supported by funding from the WSIB Ontario grant program.

Project Advisory Committee

This project is supported by a project advisory committee of stakeholders. A list of advisory committee members and meeting minutes are located on the project advisory committee page.

Research Team:

Tracy Kirkham (OCRC, University of Toronto), Principal Investigator
Paul Bozek (University of Toronto), Secondary Lead
James Scott (University of Toronto), Co-Investigator
Chris MacDonald (OCRC, University of Toronto), Co-Investigator
Rachel Tyli (OCRC, University of Toronto), PhD Student, Study Coordinator

If you have questions about the study, study procedures or would like to enroll, you can contact the study coordinator, Rachel Tyli at or view the enrolment page to see if you are eligible.