The use of medical cannabis by patients who are employed and actively working raises the issue of impairment in the workplace. The employer has the right to expect all employees to be fit for duty although the discussion around impairment is most critical when a safety sensitive position is in play.

In Canada, the employer also has the duty to accommodate medical cannabis patients. This requires the employer to evaluate if an employee is in fact impaired from their prescription drug use.

We lack a clear definition of impairment resulting from cannabis, which only further complicates this issue. This makes the partnership between the physician, employee-patient and employer very important.

In the case of City of Calgary v. CUPE, Chuck Hanmore held a medical cannabis prescription and disclosed this to management. As a heavy equipment operator, his position was safety sensitive. Due to a lack of internal process, no action was taken upon disclosure and Hanmore was allowed to remain in his position for two years. Eventually, when someone took notice, he was removed from his job and accommodated in a lesser position.

But the demotion turned out not to be a permanent move. With the assessment of an independent physician it was determined that even though Hanmore consumed medical cannabis, he was not impaired at work and was fully reinstated into this job as a heavy equipment operator.

How was this conclusion reached? The physician assessed Hanmore's cannabis prescription, including how much he was prescribed, how much he used on a daily basis and the time of day he consumed cannabis.

Although there was no set limit on how much Hanmore could consume on a daily basis, he explained he typically consumed one-third of a gram per day. This was done in the evening and he explained that he did not consume at work.

Through consultation with the physician, Hanmore agreed to a specific dosing regimen. He agreed to have his maximum monthly prescription reduced to 10 grams per month, which was in alignment with his daily dosing. He would continue to consume in the evening (after work) so he wouldn't be impaired when he reported for work in the morning.

The fact that Hanmore performed his duties for two years without incident was also in his favour.

This is an important decision that highlights the need for individual assessment of an employee's circumstances prior to permanently removing them from their job and impacting their earning power.

What are the key takeaways from this situation:

• Where employees hold safety sensitive roles they should be prepared to have a conversation with their physician about impairment.
• Employees should not be surprised if employers request medical evidence to support their claim of being fit for safety sensitive work.
• Employers need to assess impairment on a case-by-case basis. Dosing, method of consumption, strain, consumption frequency and consumption timing relative to commencement of shift all play a role in determining if an employee is impaired or not.
• Employers need to train their managers on rights and responsibilities related to medical cannabis so that disclosure is not overlooked.
• Employers need to be aware that there could be a situation, such as this one, where after a proper investigation it is determined that a cannabis patient is fit to perform safety sensitive work.