The legalization of cannabis has some employers wondering about their powers to discipline workers who are high on the job. This issue becomes more complicated when weed is being used for medicinal reasons and the employee is operating heavy equipment.

Two 2015 legal decisions—one at B.C. Human Rights Tribunal and the other involving a Calgary city employee’s grievance—offer some guidance.

In the first case, B.C. Human Rights Tribunal member Robert Blasina ruled that a northwestern B.C. logging contractor did not violate the provincial human rights code when it terminated a cancer survivor, John French, who smoked cannabis on the job to manage his pain.

French did not have a card from Health Canada designating him as a medicinal cannabis user, though his doctors condoned his consumption as long as it worked. According to theruling, French insisted that he was never high on the job, even though he would smoke a joint in the morning, in the middle of the day, in the evening, and before going to sleep “if there’s pain”.

He was dismissed three weeks after he “struck a moose on the road while driving company truck to work”, according to Blasina’s decision.

Selkin Logging claimed that workplace safety trumped any duty to accommodate his cannabis use. It maintained that its policy of no drugs in the workplace was permissible under B.C.’s Occupational Health and Safety Regulation.

Even though French’s complaint was dismissed, the ruling noted that the Occupational Health and Safety Regulation “does not provide an absolute prohibition against substance use at the workplace”.

Rather, it concerns whether “the person’s ability to work is affected by alcohol, a drug or other substance so as to endanger the person or anyone else”.

“Zero tolerance for marijuana at the workplace, as a safety standard, surpasses the standard of not being impaired at the workplace,” Blasina wrote.

In the Calgary case, heavy-equipment operator Chuck Hanmore had a card from Health Canada authorizing him to consume up to three grams of cannabis per night to deal with chronic pain from a degenerative neck disease. He testified that he only used one-third of a gram each evening.

The city determined in 2012 that he could not return to “safety-sensitive service”. A doctor specializing in addiction concluded that he “suffered a dependency on marijuana”, based on an admission that he had been consuming weed for 15 years. This specialist did not speak to Hanmore’s physician.

After Local 37 of the Canadian Union of Public Employees filed a grievance, two of three panel members concluded that the employer “fundamentally created the ‘dependency’ issue”.

The majority also concluded the city’s investigation was designed to look for ways to prevent Hanmore from performing his duties rather than establishing the facts.

He was reinstated to his position on the condition that he submit to random testing for substances and that the employer could perform random work-performance monitoring.

Hanmore was also instructed to consult with his doctor about asking Health Canada to reduce his monthly allowable medicinal-cannabis allotment to 0.3 grams per day.

This year, the Human Rights Tribunal upheld the dismissal of a high-rise painter who smoked marijuana at work to deal with chronic pain.

“The evidence is overwhelming that this is a safety sensitive workplace,” wrote tribunal member Colin Johnston in his February ruling. “Prohibiting the use of impairing drugs seems more than reasonable in the context of this job site and the risks involved in any workplace errors.”