Despite cannabis legalization, impairment testing still hazy

Cognitive and behavioural testing methods gaining ground

Despite cannabis legalization, impairment testing still hazy
Urinalysis testing can detect the presence of cannabis in the body for a period of days to weeks, depending on the worker’s history of use. Tippapatt/Shutterstock

While recreational cannabis has been legal in Canada for more than a month, the workplace testing process surrounding the drug remains unchanged.

Safety-sensitive employers continue to turn to urinalysis and oral-fluid testing to determine the presence of cannabis in workers, though pinpointing levels of impairment in individual workers continues to be “quite ineffective,” said Alison McMahon, CEO of Cannabis at Work, a cannabis consulting and training company in Edmonton.

“In either case, we’re not actually getting an indication of impairment,” she said. “We’re only getting an indication of recent use — even with the saliva swab.”

“Do I think that they’re sufficient? No, I don’t,” said McMahon. “There’s going to be employers that are going to get challenged around disciplining individuals for recreational cannabis use, but not being able to show impairment.”

Regardless, legalization has put workplace safety squarely on the front-burner, said Melissa Snider-Adler, chief medical review officer at DriverCheck, a workplace medical testing company in Ayr, Ont.

“It’s allowed employers to engage in more conversations around safe workplaces and what that means, and around substance use in workplaces,” she said.

“People are talking about it. When people start talking about it, they develop better workplace alcohol, drug and fit-for-duty policies, and part of that may include doing drug testing.”

Testing options

Traditional drug testing options available to employers are urinalysis and oral-fluid testing, while blood testing remains too invasive, said Snider-Adler.

Urinalysis testing can detect the presence of cannabis in the body for a period of days to weeks, depending on the worker’s history of use, she said. A mild user may only test positive for two days after use, while a chronic user could test positive for weeks following.

Oral-fluid testing consisting of a saliva swab submitted to a laboratory provides a much narrower window of drug use, said Snider-Adler.

“That picks up very recent use for THC (tetrahydrocannabinol),” she said. “It picks up what we call the parent drug, or the active drug, the one that makes you high, the one that causes euphoria, THC, delta-9 THC. That’s what it picks up… The urine test is testing for the metabolite or the breakdown product, but the oral-fluid test is for THC.”

Companies have been testing oral fluid and urine for many years, said Snider-Adler.

“This is not a new test, it’s not a new science. It’s just that there are more companies considering oral-fluid testing now in light of legalization.”

In response to legalized cannabis, some safety-sensitive employers in Canada have banned the drug entirely, as impairment can be known to last for weeks, she said.

Others have stuck to urinalysis, while still more are switching to oral-fluid testing to narrow the window of impairment.

While more companies have shown interest in oral-fluid testing, urinalysis remains more widely used because it is integrated into many safety framework models, collective agreements and employer policies, said McMahon.

“While I think that there is an interest (in oral-fluid testing), and we’re seeing a shift in that direction, there’s some kind of institutionalization of urinalysis into some of our systems that doesn’t make it that easy to just switch right away.”

Employers are deemed safety-sensitive when an employee’s impairment could result in harm or severe consequence to themselves, others or the environment, according to Snider-Adler.

Some organizations do conduct random testing of employees, but the majority are still reasonable cause tests, completed if visible signs of impairment are present, or following an incident or near-miss, she said.

Going beyond simple tests

At present, there is no universally accepted method of testing for cannabis impairment, said Ryan Wozniak, vice-president of legal at Peninsula Canada, an HR consultancy in Toronto.

But that doesn’t give employees free rein over their cannabis consumption. Employers need to implement policies that “prohibit the consumption of cannabis in the workplace and during breaks,” he said.

Non-invasive impairment testing methodology could also be implemented, said Wozniak, such as performance indicators and objective observation tests.

Some companies have begun conducting cognitive testing to determine impairment, rather than simply testing for presence of drugs, said Snider-Adler.

However, cognitive and behavioural testing methods require further validity before they will earn widespread adoption, she said.

“A lot of them go hand-in-hand with drug testing to give a bigger picture and more pieces of the puzzle that help you to see really what’s going on,” said Snider-Adler. “I expect in the future that we will see more of these types of testing perhaps being utilized in the workplace.”

The legalization of recreational cannabis has refocused safety professionals on workplace impairment issues, said McMahon.

“Obviously, there’s a significant number of things that can impact whether somebody is impaired in the workplace, and fatigue is one of the largest ones,” she said.

“What’s exciting about (cognitive testing options) is it would give an indication of a person’s cognitive functioning or cognitive impairment level, but it’s not necessarily focusing on one specific reason.”

Advice for HR

From a legal perspective, it is important that any “final decisions” on employment are based on the results of laboratory tests, rather than initial screenings alone, said Snider-Adler.

And employers do not have an “unequivocal right” to test employees for impairment, said Wozniak.

While the law in Canada remains unclear as to what forms of mandatory or random drug testing are permissible, courts generally have a greater tolerance for drug testing policies in safety-sensitive work environments, he said. In general, random drug and alcohol testing policies that deny a person employment following a failed test are forbidden on the basis they unfairly assume the employee has an addiction problem.

“The bottom line is that employers must implement policies that are reasonable and appropriate, having regard for the specific conditions present in the workplace,” said Wozniak.

“Employers can and should prohibit the use or possession of cannabis in the workplace by implementing, using and enforcing a proper drug and alcohol policy,” he said.

“The policy should clearly outline the disciplinary procedure that will be followed in the event that an employee violates (it).”

Accommodation to the point of undue hardship should also be accounted for in the policy, and zero-tolerance positions should be avoided, said Wozniak.

General cut-off limits in terms of cannabis are 50 nanograms of THC per millilitre for urinalysis and five nanograms per millilitre for saliva swabs — but employers are able to set their own limit, said McMahon.

Going forward, employers should continue to ensure testing policy is as defensible as possible, she said.

Strong policy “indicates that if an employee is subject to drug testing and they’re over a cut-off limit at that test, that there will be consequences; there will be discipline up to and including termination, potentially.”

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