Courting Marijuana and Measures of Impairment

As the legalization of recreational marijuana is approaching, many employers are struggling to develop policies to respond to this change in policy.

Courting Questions of Impairment
A frequently asked question is how does an employer know when an employee is impaired by marijuana use? For many other substances, a relatively simple test can determine whether or not an employee is under the influence of an intoxicant and to what level. At present, this is not the case with marijuana. At the current state of testing technology, there is no test that enables an employer to determine whether an employee is impaired by marijuana.

A recent decision may provide some relief to employers from this challenge. In the decision in Lower Churchill Transmission Construction Employers’ Association and IBEW, Local 1620, the arbitrator concluded that the lack of an accurate test for marijuana impairment caused an undue hardship for the employer.

In this case, the grievor suffered from some significant health issues. He eventually obtained an authorization to use medical marijuana and used 1.5 grams by vaporization each evening to manage chronic pain. His doctor gave him the usual rules that he was not to perform certain activities such as driving within four hours after ingestion by vaporization.

The grievor applied for a job as a utility worker and subsequently as an assembler. Both these positions were deemed to be safety sensitive, and he was awarded neither because of his use of medical marijuana. This denial was made notwithstanding that the grievor had worked previously on the project without any problematic work performance. The union filed a grievance and stated that the employer had failed to accommodate the employee’s medical problems.

The Safety of Accommodation
The employer argued that it had an overriding obligation to ensure the workplace was safe and that no worker could attend in an impaired state—especially those in safety sensitive positions. Moreover, impairment was a recognized effect of ingesting marijuana and is was very difficult to know with any precision how long an individual would remain impaired after ingestion. The fact that the employee had worked previously without a problem could have just been a fortunate coincidence.

The arbitrator accepted that in both positions there were times where the worker had to demonstrate a high level of alertness or an accident could occur that could injure the worker or other employees.

When grappling with the duty to accommodate, the arbitrator observed that an employer was required to accept some risk in the accommodation process. However, the employer was entitled to be able to receive accurate medical information regarding impairment to determine if an employee could safely work.

The arbitrator noted that THC effects both judgment and motor skills and is known to cause impairment. Health Canada had advised healthcare practitioners that impairment from THC can last more than 24 hours and that length of impairment is variable even in the same individual. Health Canada had similarly warned that the ability to drive or perform other dangerous tasks could be affected for up to 24 hours post consumption.

Lacking Measure is not Lacking Risk
In light of these findings, the arbitrator stated that he did not endorse the doctor’s advice that the employee could work in a safety sensitive position 4 hours after ingestion. He accepted the employers argument that is must be able to accurately measure impairment for an employee using medical marijuana in a safety sensitive position. If the impairment could not be measured, than it was impossible for the employer to manage the risk associated with any potential impairment on the employee’s performance.

The employer was not required to have “conclusive evidence of workplace impairment.” Such a requirement was unachievable and placed an unrealistic burden on the employer. Accordingly, the employer had reached the point of undue hardship and it was not required to place the grievor in the sought after positions. The arbitrator summarized his findings as:

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 last up to 24 hours after use.

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 time limits.

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 understand the interaction between cannabis impairment and appropriate work restrictions in a given fact situation.

This decision is important because it recognizes the quandary that employers can find themselves in when trying to accommodate medical marijuana use. While this case will likely be appealed, it provides the basis on which a further discussion can be held regarding what may or may not be appropriate when dealing with similar issues.

Graeme McFarlane is a partner at Roper Greyell LLP which is a firm focused on partnering with companies to find solutions to workplace legal issues.

PeopleTalk Summer 2018


Raising the Bar


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