By: Matthew Kimevski

Prominent unionized workplaces such as the Toronto Police Service[1] and University Health Network[2] have begun requiring vaccinations from their employees. With the announcement of mandatory COVID-19 vaccination policies, some may be left wondering on what basis employers can impose such policies. Fortunately, we may learn some valuable lessons from past labour arbitrations.

First, it is important to note that employers have a duty to take every reasonable precaution to protect their workers.[3] However, it is not certain how this duty would apply in the context of COVID-19. How an employer should go about protecting their workers depends on the workplace. Some may feel like mandating vaccinations is appropriate, while others may think simply encouraging vaccination is as far as they should go. Regardless, when an employer mandates vaccination in the unionized workplace, there are some legal considerations, as will be discussed.


With respect to labour law, past arbitration between employers and unions shows that some vaccine policies can be considered reasonable, while others are not.

It’s important to note that if a vaccination rule or policy is introduced by the employer and was not agreed upon by the union, there are certain requirements that must be met:

  • it must not be inconsistent with the collective agreement
  • it must not be unreasonable
  • must be clear and unequivocal
  • must be brought to the attention of employees affected
  • employees must be notified that a breach of the rule could result in their discharge if such a rule is a foundation for discharge, and such rule must be consistently enforced by the company.[4]

If an employer fails on any of these factors, an arbitrator will likely find the policy unenforceable.[5] The arbitrator will also require the employer to demonstrate the policy is for a legitimate business interest, such as safety.[6]

What Can We Learn From Union Disputes?

While arbitrations may not have precedential value, arbitration dealing with influenza vaccine mandates in the healthcare sector provides insight into the permissibility of COVID-19 vaccine mandates in the workplace. Most arbitrators agreed that mandating vaccination in workplaces dealing with at-risk people is reasonable.[7] Arbitrators found the mandates were reasonable because they reduced transmission of the flu; thus, possibly saving the lives of their patients,[8] and the inherent purpose of the policy was to prevent further transmission of the virus.[9]

There were arbitrations where vaccine mandates were found unreasonable because they operated on a “Vaccine or Mask” (VOM) policy,[10] requiring employees to get vaccinated or wear a mask. In one case, the policy was found unreasonable because surgical masks were deemed ineffective at stopping influenza, and asymptomatic spread was rare. Thus, the arbitrator concluded the Vaccine or Mask policy was illogical.[11]

When the arbitrations above occurred, masks were not mandated by the government, so a “Vaccine or Mask” policy by an employer today would not only be unrealistic, but also dangerous and unreasonable because they wouldn’t be in compliance with government standards.[12]

When exploring vaccine mandates and masking, for the immediate future they will likely be paired together in order for a policy to meet the standard of reasonableness. Studies continue around the effectiveness of masks at preventing COVID-19, and findings indicate surgical, cloth, and even N95 masks don’t offer anywhere near 100% protection.[13] Additionally, vaccine effectiveness against the delta variant is only around 60% effective at stopping infection,[14] and the CDC has indicated vaccinated individuals are still able to spread COVID-19.[15] This supports the finding in the St. Michael’s Hospital arbitration, where the arbitrator said that a vaccine and mask policy should be used unless a vaccine provides 100% effectiveness.[16] The dispute highlights that while vaccine mandates and mask requirements are reasonable, employers should refrain from choosing a Vaccine or Mask policy and instead implement a Vaccine and Mask policy.

In exploring the validity of a unilaterally imposed policy, arbitrators will balance the interests of the employer and the employees, and determine the proportionality of the benefit the rule has to the workplace compared to the harm the policy may have on employees’ privacy.[17] Getting vaccinated is a medical procedure and normally there is no obligation to disclose one’s medical history, but COVID-19 is highly transmissible and poses a significant risk to vulnerable people of all ages.[18] When balancing the interests of employees and an employer, an arbitrator may determine safety trumps privacy.[19]

The employer will have to demonstrate that COVID-19 is a safety concern to their workplace and that their policy is proportional to the harm it may cause employees.[20] This is in accordance with the reasoning of Irving Paper and Pulp,[21] a case that involved mandatory alcohol testing at work. It should be noted that in Irving Paper and Pulp, mandatory alcohol testing was deemed unreasonable and not proportional to the risk intoxicated workers posed to the workplace. The arbitrator found there was a lack of evidence that workers were showing up intoxicated.[22] Not only do employers have to prove the existence of a threat, they must also show there are no other less intrusive methods to address the issue.[23]

Applying the reasoning to our current situation, employers in the healthcare sector and even police force would arguably be able to show that COVID-19 is a threat to their workplace, because outbreaks have occurred in these workplaces.[24] Additionally, less intrusive methods like only requiring masks, daily testing, etc., may not be enough to stop the spread of COVID-19. This is because masks are not 100% effective at stopping COVID-19,[25] and these are jobs where employees come in contact with at-risk people. Thus, the benefits of mandating the vaccine could be proportional to the loss of privacy an employee may face.


When vaccine mandates are applied to unionized workplaces, the most important factor is that the policy must not be unreasonable. Employers must ensure that the benefits of the policy are proportional to the loss of employee privacy. If employees have no contact with customers and are usually isolated from each other, such a mandate may be unreasonable and not proportional. On the other hand, employees that deal with the vulnerable may be reasonably mandated by the employer to take the COVID-19 vaccine, noting the threat posed to others is high.

Disclaimer: The information provided in this response is for general informational purposes only and is not intended to be legal advice. The content provided does not create a legal client relationship, and nothing in this response should be considered as a substitute for professional legal advice. The information is based on general principles of law and may not reflect the most current legal developments or interpretations in your jurisdiction. Laws and regulations vary by jurisdiction, and the application and impact of laws can vary widely based on the specific facts and circumstances involved. You should consult with a qualified legal professional for advice regarding your specific situation.

[1] Megan Devlin. DH News. Toronto police union opposes mandatory vaccination policy. Website:

[2] Ashima Agnihotri. Toronto Star. UHN will require employees to get vaccinated against COVID-19 by late October or face termination. Website:

[3] Occupational Health and Safety Act, RSO 1990, c O.1, s. 25(2)(h)

[4] Re Lumber and Sawmill Workers’ Union, Local 2537 v KVP Co. Ltd. (1965) 16 LAC 73 (Robinson) para 34

[5] David J. Doorey. The Law of Work: Complete Edition. (2017) at page 617

[6] Ibid

[7] Trillium Ridge Retirement Home v SEIU Local 183 [1998] OLAA No 1046 (Emrich); and Health Employers Assn. of British Columbia and HSA BC (Influenza Control Program Policy), Re (2013), 237 LAC (4th) 1 (Diebolt)

[8] Health Employers Assn. of British Columbia and HSA BC (Influenza Control Program Policy), Re (2013), 237 LAC (4th) 1 (Diebolt) at page 82

[9] Ibid at page 89

[10] St. Michael’s Hospital v Ontario Nurses’ Association, 2018 CanLII 82519 (ON LA)

[11] Ibid at page 53

[12] Government of Ontario. Reopening Ontario. Website:

[13] Sam Raskin. New York Post. Study finds N95 masks more effective than surgical, cloth coverings against COVID-19. Website:

[14] Israel Ministry of Health. Decline in Vaccine Effectiveness Against Infection and Symptomatic Illness. Website:

[15] CDC. Outbreak of SARS-CoV-2 Infections, Including COVID-19 Vaccine Breakthrough Infections, Associated with Large Public Gatherings – Barnstable Country, Massachusetts, July 2021. Website:

[16] Supra note 10 at page 50 – 52

[17] Communications, Energy and Paperworkers Union of Canada, Local 30 v. Irving Pulp & Paper, Ltd., 2013 SCC 34 (CanLII), [2013] 2 SCR 458

[18] Mayo Clinic. COVID-19: Who’s at higher risk of serious symptoms?. Website:

[19] Supra note 17 at para 4

[20] Supra note 17 at para 52

[21] Supra note 17

[22] Supra note 17 at para 47

[23] Supra note 17 at para 27

[24] 680 News. Toronto police confirm COVID-19 outbreaks at 31 Division, police college. Website: ; and UHN. COVID-19 Outbreak Information at UHN: Outbreaks Declared Over. Website:

[25] Supra note 13