✕
Get involved
Back to all

Comment by August 19th on CSA Draft for Respirators in the Workplace

Authors: Katelyn Miyasaki, Ifrah Ahmad, Claire Alexander

Intro to the CSA Draft

Recently, the Canadian Standards Association (CSA) put out a draft highlighting an updated standard of respirators in workplaces that includes specific provisions for healthcare settings. The WHN has issued a statement supporting the draft: https://whn.global/whn-response-to-canadas-csa-z94-4-25-respirator-standard/. Public comments can be made by anyone worldwide who registers, not just Canadian citizens, and doing so is free. We encourage everyone to register at the following link and make public comments on the draft ahead of the August 19th deadline: https://publicreview.csa.ca/Home/View/2256677. More information on the draft and instructions for how to make comments can be found here: https://donoharmbc.ca/national-standard-for-n95s/. 

CSA Z94.4 is not legislation, and it is important to be clear about what it does and does not do. The proposed update (Z94.4-25) does not mandate universal N95 use in medical settings any more than it mandates standards in other settings. For comparison, the CDC in the U.S. also lacks regulatory authority but sets widely adopted standards of practice. What Z94.4-25 does is recognize medical workplaces as environments where respiratory protection programs (RPPs) should be subject to a technical standard and then defines that standard.

The key shift is that health care is explicitly acknowledged as a setting where airborne protection is relevant, just as it is in other high-risk workplaces. That wasn’t the case in earlier versions. While implementation remains voluntary in many jurisdictions, CSA standards carry weight: they help define the professional standard of care, and are often incorporated into legal, regulatory, and institutional decisions—including in health care.

This newsletter will discuss the key content of the standard. focusing on Clauses 7, 8, and 9, which discuss hazard analysis and the selection of respirators for general and healthcare workplaces. Sections 8 and 9 are both based on science presented in section 7. Clause 8 focuses on the general workplace, while 9 focuses on the healthcare workplace, the largest workplace sector in Canada.

The WHN is in support of the CSA Draft, as it supports the underlying science on the importance of respirators in healthcare settings in mitigating harm and the risk assessment of airborne infection more generally speaking. Where specific suggestions for improvements are possible, these will be pointed out. 

Summary of the CSA Draft Topics

Clause 7 discusses hazard identification and risk analysis. Section 7.2 covers the identification of various respirable hazards. Section 7.3 classifies various workplaces in terms of risk level: healthcare facilities are at a W3 risk level since “workers are considered always at risk of elevated exposure to human bioaerosols,” crowded workplaces and those with certain ventilation issues are at a W2 risk level “substantial risk of infection from co-workers during pandemic circumstances, and other workspaces are at a W1 risk level.

Section 7.3 also discusses the source-pathway-receiver model of transmission and the assignment of hazard levels for various pathogens. This involves summarizing sources of bioaerosols; source controls such as wearing respirators; factors affecting pathways, including humidity and ventilation; pathway controls, including filtration and layout; receiver-related factors; and risk levels of exposure. Level A means risk is very low due to engineering controls or an absence of a source of bioaerosols, Level B means that a source of bioaerosols is present but pathway controls are generally effective, still limited effectiveness leads to requirement for respirators, and Level C means that both source and pathway controls are not effective and respirators are required to prevent inhalation of bioaerosols. In Level B and Level C areas, respirators should be worn. 7.3.1 includes a list of COVID risk assessment tools, with Figure 1 of 7.3.4 including a graphic explaining the source-pathway-receiver model, as well as lists of controls and risk factors that must be included in risk assessments. Section 7.4 discusses the timing of reassessments.

Fig 1: Graphic explaining the Source, Pathway, receiver model included in section 7.3 of CSA Z94.4

Clause 8 discusses general workplaces excluding healthcare. Section 8.2 clarifies that respirator selection shall be conducted by qualified persons and that recommendations in the standard are based on NIOSH and CSA certifications. Section 8.2 also shows a flow chart for respirator selection in the general workplace based on considerations such as fluid resistance, flammability, source control, eye protection, and breathability, and Table 3 identifies appropriate respirators for various protection levels.

Section 8.3 discusses considerations surrounding bioaerosols in the general workplace, including physical aspects of the workplace, the presence of a pandemic or effective infection risk management mode, and the hazard level of the pathogen. For Hazard Levels 1-3, the qualified person should use control banding to identify the risk of airborne spread, considering the amount of aerosols generated, frequency of contact, and pathways controls present to determine the control band and necessary respirator type.

Clause 9 discusses healthcare workplaces. Section 9.2 explains that healthcare-specific guidelines apply in all facilities where a healthcare procedure is being performed, as well as hospitals, ambulances, and care homes. Section 9.3 provides for respirator exempt zones engineered to prevent transmission. According to section 9.4, in workspaces without Hazard Level 4 pathogens, healthcare workers are required to wear a respirator with protection level 1 in Table 3 or better, and, in workspaces with Hazard Level 4 pathogens, healthcare workers are required to wear a respirator correlating with protection level 4 or better.

Table 9 in Section 9.5 provides a workflow for identifying the appropriate respirator type in healthcare environments. Section 9.6 mentions exemptions for certain locations and individuals at the discretion of a qualified person and also covers training, fit testing, seal checking, availability, breathability, reusability, and recycling. Finally, Section 9.6 highlights that surgical masks are not respirators and can be used only as a back-up form of source control. 

Take Action Now!

We encourage all WHN members to make public comments on the CSA standard draft. There are three possible types of comments: General, Editorial, and Technical, defined as follows by the CSA (https://publicreview.csa.ca/Home/Page/Help):

  • General – Comment on the document as a whole, using the current section as a starting point or as an example.
  • Editorial – Comment on spelling, grammar, punctuation or layout that does not affect the application of the document.
  • Technical – Comments which have practical implications on the application of the document.

Please leave a general comment stating support for the standard as a whole. There are some example comments on WHN’s statement of support here: https://whn.global/whn-response-to-canadas-csa-z94-4-25-respirator-standard/#Sample_Comments. 

We also recommend the following specific technical comments. Please reword as you see fit!

  • Section 9.6.2 would be strengthened by requiring patients and visitors to wear respirators, not merely recommending it. This helps prevent the spread of infectious disease and safeguards healthcare worker, patient and visitor safety. Furthermore, it should be a priority to implement other layers of protection as well, including COVID-19 testing prior to entry. This is an important and well-established protection measure that would limit exposure inside the healthcare workplace. 
  • Section 9.6.3.1 defines the Qualified Person who implements the Respiratory Protection Program. Notably, the proposed standard specifies that exemptions must be approved by experts in “Occupational Health and Safety and/or Respiratory Protection Equipment”—an assumption that, if taken seriously, meaningfully narrows the door for misuse. However, it may be helpful to have more specific guidance on what constitutes a Qualified Person.
  • Section 9.3.6.10 covers exemptions to wearing required respirators. We recommend clear, science-based exemption standards rather than leaving it up to the Qualified Person. WHN has previously issued guidance allowing for the removal of respirators in specific contexts where other measures such as directed airflow, occupancy limits, testing, or engineering controls provide adequate protection. Part of the purpose of such clauses is to account for situations where respirator removal is essential, for example, during dental procedures or anesthesia, making the development of clear, science-based exemption standards critically important.
  • Section 9.3 states: “Healthcare facilities may permanently designate respirator exempt zones for areas designed in accordance with CSA Z8000:24 to provide engineered protection for occupants against aerosol transmission equivalent to the protection of a CA-N95 respirator.” These areas are also designated by the Qualified Person. We suggest that exempt zones be reassessed regularly. 

We also note that Do No Harm BC here also contains example comments.