Ontario Labour Arbitration Decision Shows Proving Cannabis Impairment Is Key to Upholding Termination

Quick Hits

• An Ontario labour arbitrator accepted eyewitness evidence of an employee’s cannabis use based on the distinct smell of marijuana, finding this constituted “clear and cogent evidence” even without formal drug recognition training.
• The employee’s dismissal was reduced to a three-month suspension because the employer did not prove observable impairment—only that cannabis was consumed during working hours.
• The employer’s delayed response—waiting until the next day to escalate the concern—eliminated the opportunity to document signs of impairment.

Background Facts

The employee left the plant and went for a walk during his lunch break. The quality manager, who was also on lunch, saw the employee at a nearby intersection smoking what appeared to be a hand-rolled joint and testified that he smelled cannabis, with the odour intensifying as he approached.

However, the quality manager did not report the incident immediately. After finding the general manager’s door closed, he chose to wait until the next day to raise the issue, by which time any opportunity to assess or document impairment had passed.

When confronted, the employee denied smoking cannabis and claimed it was a cigarette. He responded with significant insolence, repeatedly shouting derogatory remarks at the operations manager after being advised that he was suspended pending investigation. His employment was subsequently terminated.

Arbitrator’s Findings

The arbitrator found that the employer proved, on a balance of probabilities, that the employee was smoking cannabis. The evidence of a distinct and recognizable cannabis odour while it was being burned was accepted as clear and cogent evidence of use, and the quality manager’s familiarity with the smell was sufficient, despite having no formal training.

However, the employer failed to prove impairment. There was no evidence of diminished performance, motor skills, or alertness, and by the time the matter was reported, it was too late to assess impairment. While the arbitrator accepted the employee may have returned to work within a period of influence, that alone was insufficient to justify termination.

Given the safety-sensitive workplace, dishonesty, insolent behaviour, and prior discipline—balanced against nine years of service and the absence of any safety incident—the arbitrator substituted a three-month unpaid suspension for termination and declined to award retroactive compensation.

Key Takeaways

This case demonstrates that while employers can successfully prove cannabis use through eyewitness testimony, particularly through the distinctive smell of marijuana, termination may not be upheld without evidence of actual impairment.

Delay in taking out of service an employee who has been observed smoking cannabis, and failure to note signs of actual impairment, can negatively impact the employer’s case for just cause supporting termination.

Observable indicators of impairment that can be documented in disciplinary cases can include:

• Demeanor and behavior
• Eye appearance (redness, glassiness)
• Speech patterns
• Motor coordination
• The smell of cannabis on clothing or person
• Any admission or statement by the employee

The arbitrator’s decision to impose a three-month unpaid suspension, while declining any back pay due to the employee’s insolent conduct, shows that arbitrators take workplace cannabis use seriously, particularly in safety-sensitive environments. But the difference between a suspension and a termination may come down to whether the employer acted quickly enough to capture the evidence of impairment.

Ogletree Deakins’ Canada offices will continue to monitor developments related to cannabis use in the workplace and will provide updates on the Canada, Cross-Border, Drug Testing, and  Workplace Safety and Health blogs as additional information becomes available.

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