Medical Marijuana – Undue hardship in the Context of a Safety Sensitive Workplace

Medical Marijuana – Undue hardship in the Context of a Safety Sensitive Workplace

Ontario’s Human Rights Code (the “Code”) protects individuals with disabilities from discrimination in the context of employment. In that regard, the Code requires employers to accommodate individuals with disability-related needs, up to the point of “undue hardship”.

Accommodating an employee who needs to use medical marijuana may require an employer to modify hours of work, allow for additional breaks, allow for the modification of duties, and/or assign the employee to a less demanding position, again, up to the point of “undue hardship”.

The inclusion of the term “undue hardship” in the Code reflects the fact that an employer’s duty to accommodate is not limitless. The fact that an employee has a medical document which allows him or her to use medical marijuana does not mean that the employee has a right to be impaired at work, particularly where that impairment could threaten the health and safety of the employee, his or her co-workers or members of the general public. At least in theory, where circumstances call for it, employers are permitted to require that the employee not report to work in an impaired state.

A) Inadequacy of Available Testing Methods regarding Impairment

But what about circumstances where it is difficult, or in some cases impossible, to accurately measure “current impairment” or “residual impairment”?

For many prescription drugs, including medical marijuana, accurately establishing the effect or degree of impairment is not as simple as requiring an employee to blow into a tube. Unlike alcohol, the amount of THC (the active medical ingredient in cannabis) that is present in an individual’s bloodstream does not accurately represent the degree of impairment that individual may be experiencing. Complicating matters further, trace amounts of THC can remain in a cannabis user’s bloodstream well beyond the period in which they would generally experience impairment, which could lead to a “false positive” on a drug screening evaluation up to several weeks after consumption.

THC sensitivity is also linked to an individual’s long-term exposure to the substance –  individuals can build up a tolerance which makes THC less effective (as with other psychoactive medical substances). In other words, someone who regularly uses cannabis for medical purposes might have very high levels of THC in their blood, but show no signs of being impaired. By contrast, an infrequent user may show comparatively low levels of THC in their blood but show severe signs of impairment.

It is true that many of the above observations might apply to alcohol, however alcohol has a long history as a regulated substance in this country, including well documented, established and easily tested per se limits (regardless of actual “impairment”). The rules and regulations that apply to alcohol are very clear, whereas the corresponding rules relating to the consumption of cannabis are not.

The federal government has proposed various per se thresholds and regulations that would apply to marijuana, dating back to April 2017. The federal government has also promised that it has been extensively evaluating road-side saliva-based testing methods which would allow for an immediate result, and one that would not require a blood, hair or urine sample to be sent to a lab for testing (which would ostensibly occur over the course of several days).

While per se limits – the “tolerable amounts” of THC in the bloodstream – for marijuana have been proposed under federal Bill C-46, they have not been formally established by regulation. At present, no drug-screening device(s) have been approved by the federal government for roadside or other testing. Marijuana still remains a controlled, illegal substance, and law enforcement agencies like the RCMP and Ontario Provincial Police are employing standard police Field Sobriety Tests (i.e. testing auditory / visual acuity and motor function) to determine impairment. If an individual fails a Field Sobriety Test (suggesting impairment), law enforcement authorities can order a Drug Recognition Evaluation (or “DRE”), which can involve a saliva sample or a more invasive bodily fluid analysis that tests for all potentially impairing substances, including controlled substances like cannabis.

In relevant sum, there remains significant doubt about what the federal government intends to do to address these pressing and substantial concerns. It stands to reason that until that point in time, a “zero tolerance” approach (particularly with respect to driving-related incidents) will continue to be the norm.

B) Labour and Employment Implications of the Status Quo

The Code states that three (3) considerations are relevant to assessing whether the “undue hardship” threshold has been met:

  • Cost;
  • Outside sources of funding, if any; and
  • Health and safety requirements.

As we have identified in several of our previous articles, employers are statutorily mandated by the Occupational Health and Safety Act (the “OHSA”) to “take every precaution reasonable in the circumstances” to protect the health and safety of workers.

In certain situations, this general duty may conflict with the duty to accommodate a person suffering from a disability under the Code, with the result that accommodating the individual in question could constitute “undue hardship” on the basis of bona fide health and safety requirements.

C) Relevance of Recent Case Law

The balance between bona fide health and safety requirements associated with a “safety sensitive” role and the duty to accommodate under human rights legislation was considered in Lower Churchill Transmission Construction Employers’ Association v the International Brotherhood of Electrical Workers, Local 1620, (April 30, 2018) (J.F. Roil). In this very recent decision, issued on April 30, 2018, Arbitrator John F. Roil considered circumstances where a grievor was denied employment as a result of his use of medical marijuana for pain management.

The grievor was referred to work on a construction project which involved the development of a hydroelectric power generating facility in Labrador, together with transmission lines necessary to carry the power generated from Labrador to consumers in Newfoundland and elsewhere in North America. The grievor was referred by his Union for the position of Utility Person and a subsequent role as a Tower Assembler at the employer’s project. The employer historically treated both of those positions as “safety sensitive roles”.

Prior to being referred for the aforesaid roles, the Grievor had for some time suffered from pain associated with a diagnosis of Crohn’s disease and osteoarthritis. The grievor’s family physician, after having been unsuccessful in managing the grievor’s pain with conventional medications, had referred the grievor to the Cannabinoid Medical Clinic which prescribed medical cannabis as treatment for his pain. The cannabis was to be used in the evenings only, with a four (4) hour restriction before the grievor was permitted to drive.

The employer had in place a pre-employment drug screening process due to the safety sensitive nature of the work being performed on the hydroelectric project. The grievor was not offered either the Utility Person or Tower Assembler roles after he disclosed, as part of this screening process, that he was consuming medical marijuana on a nightly basis.

Contrary to the employer’s position, the Union argued the employer’s denial of both roles was inappropriate, alleging that the employer had breached its duty to accommodate the grievor’s disability contrary to Newfoundland & Labrador’s Human Rights Act, 2010 (the HRA”). The HRA has similar protections in place against discrimination in the context of employment as those found under Ontario’s Code. The Union essentially took the position that the grievor’s physician had conclusively indicated the grievor was effectively capable of returning to his full, unmodified duties a mere four (4) hours after his consumption of cannabis.

After considering lengthy submissions made by both parties, Arbitrator Roil dismissed the grievance, finding that accommodating the grievor would constitute “undue hardship” under Newfoundland’s HRA. He specifically noted the employer’s statutory obligation to ensure a safe and productive workplace, pursuant to Newfoundland’s Occupational Health and Safety Act.

The Arbitrator agreed that both of the positions that the grievor was qualified to hold were “safety-sensitive” roles, and therefore, the employer had a right to determine whether the grievor was able to work without impairment. In that regard, both positions required the grievor to operate heavy, motorized equipment. Both roles required a significant degree of mental alertness. In the Arbitrator’s view, the risk of injury to other employees, or the grievor himself, was “significant”.

The Arbitrator agreed with counsel for the Union that every employer charged with accommodating a disabled employee has to assume a “degree of risk” as part of the duty to accommodate. Further, the Arbitrator reinforced the long-accepted principle that accommodation in the workplace requires an individual analysis of each employee’s particular situation, to eliminate the risk of typecasting or stereotyping.

Those considerations taken into account, the Arbitrator next reflected on the state of affairs regarding cannabis, including the inadequacies of current testing methods, false positives, and the complex issue of “residual impairment”. The Arbitrator agreed that THC was accepted by large organizations such as Health Canada as a drug which could significantly impair motor skills, for up to twenty-four (24) hours after the most recent dose. The Arbitrator also considered a peer-reviewed document published by the College of Family Physicians of Canada in 2014, which similarly cited Health Canada’s caution regarding driving or the performance of activities requiring “alertness”, for up to twenty-four (24) hours after dosing.

After considering all of the grievor’s medical evidence, along with the studies, guidelines and other medical documentation regarding cannabis relied upon by the employer, the Arbitrator concluded:

  1. The regular use of medically-authorized cannabis products can cause impairment of a worker in a workplace environment. The length of cognitive impairment can exceed simply the passage of 4 hours after ingestion. Impairment can sometimes exist for up to 24 hours after use.
  2. Persons consuming medical cannabis in the evening may sincerely believe that they are not impaired in their subsequent daily functioning; they can, however, experience residual impairment beyond the shortest suggested time limits. The lack of awareness or real insight into one’s functional impairment can be a consequence of cannabis use. In that context, a person may not experience ‘euphoria’ (as mentioned in the Health Canada Guidance), yet still not function, respond or react normally while impaired by cannabis use.
  3. …A general practicing physician is not in a position to adequately determine, simply grounded on visual inspection of the patient in a clinic and a basic understanding of patient’s work, the daily safety issues in a hazardous workplace. Specialized training in understanding workplace hazards is necessary to fully understand the interaction between cannabis impairment and appropriate work restrictions in a given fact situation.

The Arbitrator ultimately ruled that the employer did not place the grievor in employment at the project because of the grievor’s authorized use of medical cannabis as directed by his physician. This constituted prima facie discrimination pursuant to the HRA. However, this use created a risk of the grievor’s ongoing, and unpredictable level of impairment on the employer’s jobsite. Due to technological limitations, the employer was unable to readily measure impairment from cannabis, based on currently available technology and resources. Arbitrator Roil concluded:

…Consequently, the inability to measure and manage that risk of harm constitutes undue hardship for the Employer.

D) Key Takeaways for Employers

Arbitrator Roil’s findings should come as no surprise, particularly when considering leading medical literature regarding the degree and types of impairment caused by cannabis use, including both the short- and long-term effects of THC. The documents and peer-reviewed journals relied upon by the employer in Lower Churchill have been adopted by Canadian law enforcement agencies, who, as previously noted, currently enforce a “zero tolerance” approach to the consumption of marijuana prior to driving.

Despite the outcome in Lower Churchill, we would caution employers not to take Arbitrator Roil’s decision too far. It is important to note that the Lower Churchill decision is not binding on other Arbitrators and Courts in Canada and that it remains subject to appeal by the Union.

In our view, the Lower Churchill decision most certainly should not be interpreted to mean that employers can refuse to employ any individual merely because they disclose that they are using medical marijuana, even if the individual’s position is one that is properly considered “safety sensitive”. To the contrary, the Code, and other human rights legislation across Canada requires an employer to undergo a rigorous analysis of all facts and evidence when determining whether an employee’s disability can be accommodated, up to the point of undue hardship.

Perhaps the most controversial part of Arbitrator Roil’s decision is his commentary around the ability of the grievor’s General Practitioner (family doctor) to “adequately determine” the grievor’s “residual impairment” as a result of his consumption of cannabis. The Arbitrator’s views may not be representative of the prevailing legal approach to the validity of medical documentation. However, his approach to this issue may be adopted by Courts and adjudicators in coming years, especially if they continue to be confronted with the limitations associated with accurately measuring impairment caused by THC.

Leaving aside the foregoing caveats, Lower Churchill remains significant because it reiterates that demonstrating bona fide health and safety concerns may be the most effective way to prove “undue hardship” under the Code. In our view, Arbitrator Roil’s decision is likely to be one of many cases (arbitral and otherwise) which attempt to address this significant and relevant issue over the coming years.

Co-authored by Tushar Anandasagar and Lucas Hendsbee.

Tushar Anandasagar is an Associate Lawyer at LeClair and Associates P.C. He works in all areas of Labour and Employment law, with a particular focus on Workplace Health and Safety compliance and related issues. For further information or discussion, please contact Tushar by email at

Lucas Hendsbee is a Research Assistant at LeClair and Associates P.C. He provides research and analysis regarding all areas of the law, with a focus on regulatory compliance, policy analysis and emerging legal issues. For further information or discussion, please contact Lucas by email at

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