High times: When is a cannabis user truly impaired?

By Shaun Bernstein

Last fall’s legalization of cannabis still throws employers for a loop. Despite repeated warnings from employment lawyers that policies and procedures need updating, and that knowledge and education were paramount in dealing with the new landscape, there are still countless questions about how to work with an employee who uses cannabis. This is particularly true for medical cannabis, even though its usage has been legal for years.

One of the earliest analogies offered to employers, and one of the easiest to understand, was that cannabis should be treated like alcohol. There may be a significant difference between one drink at the office holiday party, and an employee who shows up to work too intoxicated to walk a straight line. The general guideline became the threshold for impairment — consuming the substance was not the issue as much as whether or not an individual was fit to work.

The trouble is that impairment is far more difficult to determine with cannabis, where the chemical compounds are detectable within an individual long after their usage. The question then becomes: How can you properly measure a cannabis user (medical or recreational)’s impairment?

While not an employment story in and of itself, a recent news item out of Nova Scotia may highlight the complexity of the issue. Michelle Gray, a medical cannabis user in Nova Scotia who has multiple sclerosis (MS), was given a roadside saliva test when an officer smelled cannabis in her car, and the roadside test detected that Gray had used cannabis.

However, it had been seven hours since her last usage, and while THC (tetrahydrocannabinol) can stay within the system for up to one month, Gray no longer believed she was impaired. She was nevertheless placed under arrest, and given a full sobriety test which analyzed her speech and balance (both of which could be impacted by her MS).

Gray passed the full test, and while not charged, she was still fined and had her licence suspended for seven days because she failed the roadside test.

Gray is currently challenging the law in court, although her issue relates specifically to her driving infraction. Nevertheless, the issue is the same one that has troubled employers since the introduction of medical cannabis, and on a larger scale with full legalization in 2018: How can employers detect impairment?

The answer is not a simple one. While scientists are working on more accurate testing mechanisms, the reality is that THC, the psychoactive chemical component of cannabis, may stay in an individual’s bloodstream for weeks after they have used cannabis. Thus, under the current tests available, which only look for traces of those chemicals, an individual may test positive for cannabis despite no longer being impaired, thereby creating a false positive for the purposes of measuring impairment.

While American employers may have greater liberties when it comes to randomly testing employees for impairment, the rules in Canada are far more restrictive. For Canadian employers, workplace drug testing is only permissible in rare situations, such as in safety-sensitive workplaces or after a workplace accident where drug use has been suspected as a possible cause.

Beyond those extreme circumstances, Canadian law places a heavy emphasis on a worker’s right to privacy, which places strict limits on an employer’s right to question an employee’s drug use, particularly when it does not have an impact on the workplace.

Additionally, cannabis usage may in certain circumstances be considered an addiction, which can trigger an employer’s duty to accommodate under human rights legislation, and limit the questions it can ask an employee about her medical condition.

Thus, there is no clear-cut mechanism for an employer to measure an employee’s cannabis usage, which is a hard pill for many employers to swallow. This will become a more widespread sore point this fall when edible cannabis products are legalized, and a suspicious employer can no longer detect cannabis based on a “lingering odour.”

So what is an employer to do? The answer lies in workplace policies. As we have written time and again, well-crafted policies and procedures are the answer not only to keeping a safe workplace, but maintaining the kind of workplace that employers want to run.

While employers may not be able to control an employee’s cannabis usage outside the workplace, they can set very clear guidelines regarding usage and impairment at work, and require that all workers be fit for duty when they are at work. Any policy should clearly set out expectations and consequences. This means that just because an employee is allowed to use cannabis, it does not give him free reign to do it around you or on your property.

The only caveat, of course, is for medical usage. Employees who use cannabis for documented medical purposes will have greater protection from discipline. While their usage can be governed when it comes to keeping a safe workplace, this must be done with careful sensitivity so as not to give the appearance of discriminating against their disability. That said, the duty to accommodate will not require that employers allow anyone to put their safety at risk.

In most other cases though, cannabis may be legal now but the bottom line hasn’t changed: Your workplace, your rules.

Shaun Bernstein is an associate at Rudner Law in Toronto.