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Countdown to Cannabis: A Stewart McKelvey Newsletter: The legalization of cannabis: 7 reasons why employers should take notice

Brian G. Johnston, QC

Cannabis legalization is coming. The legislation is expected to pass by July with legalization becoming effective by September.

Employers should take notice because:

1. There is already a lot of cannabis in Canada

Cannabis use in Canada is amongst the highest in the world, and the highest amongst all nations for youth consumption.

According to an EKOS survey (September 2016), 58% of Canadians have used cannabis as least once in their lifetime; 22% have used in the past 12 months; and, 5% use daily. Statistics Canada reported that, in 2017, about 4.9 million Canadians used cannabis.

Statistics Canada estimated that, at $8 per gram, the 2017 illegal Canadian market for cannabis was $5.6 billion – about 50% of the $9.2 billion Canadian beer market and 70% of the $7 billion Canadian wine market.

Cannabis use has a high level of social acceptability. Approximately 48% of Canadians agree that cannabis use is acceptable and consider that it poses less of a health risk than alcohol (41% to 49%).

Cannabis consumption is rising amongst older Canadians. By 2015, two thirds of the market was individuals older than 24 years of age.

2. More cannabis to come with legalization

Next to British Columbia, Atlantic Canadians have the highest level of support for legalization (41%) and the lowest opposition to it (35%). Nova Scotians are already Canada’s highest per capita consumers.

Use amongst working age adults is expected to increase with legalization. Some estimate that use will almost double to about 40% of Canadians (alcohol is consumed by nearly 80% of Canadians).

In Colorado, one study reports that cannabis legalization resulted in a 71% increase in the average past month use for adults 26 years of age and over (compared to a 16% increase for college aged individuals).

3. Cannabis is addictive

Cannabis is addictive. The lifetime risk of addiction is 9% versus 15% for alcohol and 32% for tobacco. The cannabis addiction rate is 17% of those who start as teenagers and 25-50% of those who smoke cannabis daily.

4. Cannabis impairs

Cannabis is different from alcohol – the effects of cannabis are more subtle and longer lasting. THC, the chemical compound in cannabis responsible for a euphoric high, is stored in the brain and fatty cells and released over time. It has a long half-life.

The duration and extent of impairment is impacted by variations in strain, crop and manufacturer; size of the joint or cookie; the depth of inhalation; and, interaction with other substances. When ingested orally, there is a lower and longer-delayed peak THC concentration.

According to a 2015 World Health Organization study, “there is ample evidence indicating that neurocognitive impairment from cannabis persists from hours to weeks. A return to a non-intoxicated state does not ensure a full return of neurocognitive function in the workplace …ensuring safety of workers who are under the influence or who recently consumed cannabis is not possible.”

5. Operating a motor vehicle – risky

The effects of cannabis on motor vehicle operation is an obvious concern.

There is a direct dose relationship between driving ability and blood THC concentration which gives rise to impairment in judgment, motor coordination, and reaction time. There is no “low risk” level of use that has been established. Dosage is difficult to determine when cannabis is smoked.

The Canadian Medical Association’s Driver’s Guide recommends abstinence from driving within five hours of smoking a single joint.

Health Canada says that the ability to drive safely and operate equipment can be impaired for more than 24 hours after cannabis use.

The Canadian Medical Association noted increased cannabis-related traffic deaths following legalization in Colorado, where cannabis-related traffic deaths increased 66% in the four-year period post-legalization, compared to the last four-year period pre-legalization.

The Final Report of the Task Force on Cannabis Legalization and Regulation in Canada (the McLellan Report) acknowledged “there is currently no evidence to suggest there is an amount of THC that can be consumed such that it remains safe to drive.”

6. The problem of residual impairment – hours to days to weeks

According to the Journal of Occupational and Environmental Medicine, the physiological effects of cannabis on neuro-cognitive performance can range from several hours to more than 28 days of subsequent abstinence.

The Journal of Occupational and Environmental Medicine says that, given that inhaled THC may impair complex human performance for more than 24 hours after ingestion, employers should not assume that [cannabis] use between shifts (such as evening use before return to work the following morning) is uniformly safe.

7. Occupational health and safety legislation – the risk to the workplace and to employers

Legislation mandates a safe workplace.

“Studies have linked [cannabis] use directly with an increased prevalence of workplace injury.” US postal workers who tested positive for cannabis on a pre-employment urine drug test had 55% more industrial accidents, 85% more injuries, and 75% higher absenteeism rate, compared with those who tested negative.”

Employers have to exercise due diligence with respect to health and safety risks.

In R v. Metron Construction Corp., 2013 ONCA 541, “three of the four deceased, including the site supervisor Fazilov, had marijuana in their systems at a level consistent with having recently ingested the drug.” The Court found that the supervisor had failed to take reasonable steps to prevent bodily harm and death by “permitting persons under the influence of a drug to work on the project”. The employer was fined $750,000. In a subsequent court action, the project manager was jailed for 3 ½ years (R. v. Kazenelson, 2018 ONCA 77).


This update is intended for general information only. If you have questions about the above information, please contact Brian G. Johnston, QC, or another member of our labour and employment group.

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