The International Society for Respiratory Protection

pdf Respiratory protection for Canadian Armed Forces members with headdress and/or beards: Powered air purifying respirators for interim use in CBRN training (Vol. 40, No. 1, 2023) Popular


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Respiratory protection for Canadian Armed Forces members with headdress and/or beards: Powered air purifying respirators for interim use in CBRN training


Dr. Paul Bodurtha1*, Dr. Eva F. Gudgin Dickson1,2, Maj. Christian Doucet3

  1. Defence Research and Development Canada (DRDC)
  2. Royal Military College of Canada (RMC)
  3. Canadian Armed Forces (CAF)

* Corresponding author and E-mail: ; tel. 403.544.4622; Suffield Research Centre, Defence Research and Development Canada, Box 4000, Station Main, Medicine Hat, Alberta, T1A 8K6



Background: The Canadian Department of National Defence (DND) and the Canadian Armed Forces (CAF) are in the process of developing inclusive solutions for chemical-biological-radiological-nuclear (CBRN) respiratory protection for CAF users. The ultimate goal is to provide a variety of low-burden CBRN respiratory protection options for operational use for all wearers, including those with facial hair and/or headdress, as well as other individuals with hard to fit faces in the context of fit testing.

Methods: In this study, the option of providing the in-service C4 and C5 CBRN respirators in a powered air form was investigated for their ability to provide adequate protection in both training and operational contexts, and for training procedures to be suitably adapted and implemented. Their performance was compared to existing requirements for the C5 respirator with regards to their ability to remove airborne contaminants via filtration, and for wearers with beards and/or headdresses, their fit factor in powered air mode, their protection factor in use via simulated workplace protection factor (SWPF) measurements, and their use in a tear gas hut for training.

Results: The flow rate through each of the two C8 filters in the powered air configuration was less than the 50 L/min at which the filters were specified and tested for approval, while the flow rates of the other two filter configurations investigated were similar to the C8. All were demonstrated suitable for use in the study and the C8’s filtration performance in the powered air (PA) configuration would be appropriate for operational use. When fit factors were measured in the PA configuration, all individuals tested achieved a value greater than 10,000. Similarly, in SWPF all individuals obtained overall protection factors of greater than 10,000. Finally, in a training activity in the tear gas hut, all individuals were able to perform the training drills successfully without exhibiting effects from the tear gas.

Conclusion: The C4 or C5 PA configuration is suitable for use in CBRN training in the tear gas hut for individuals with beards and/or headdresses, and shows promise when used with the C8 canister for operational application in a CBRN environment, with further investigation needed to demonstrate meeting all of the operational requirements.


Keywords: chemical-biological-radiological-nuclear (CBRN) protection, beards, facial hair, headdress, respiratory protection, simulated workplace protection factor, CS tear gas, quantitative fit testing, powered air purifying respirator (PAPR).