As workplaces continue to evolve their substance use policies, one recurring question is this: Can safety risk really be measured objectively? It’s a fair question and one that doesn’t have a simple answer.

While alcohol impairment testing has been widely accepted and standardized for decades, cannabis and other substances present a more complicated picture. The reality is that many workplaces still rely on outdated testing methods that provide little useful information when it comes to determining real-time safety risks.

The Limits of Traditional Testing

Alcohol testing is routinely completed using a breath specimen, which is directly correlated with blood alcohol concentration (BAC) and impairment. Cannabis and other drug testing lack this simplicity. Urine testing for reasonable cause and post-incident situations is passé. If your workplace is still using it, you’re likely missing up to 50% of the drug use that’s occurring.

Let’s break it down. Urine testing:

• only detects inactive drug metabolites
• confirms the substance was used at some point in the past, often days or even weeks ago
• cannot determine if the individual was under the influence at the time of the test
• cannot be equated with safety risk at the time of the test

Employers who continue to use urine testing in these critical situations are basing safety decisions on outdated and irrelevant data.

The Value of Lab-Based Oral Fluid Testing

By contrast, lab-based oral fluid testing offers employers a much more accurate, timely, and legally defensible option for determining recent substance use.

Oral fluid testing:

• Detects active drug presence, not just residual metabolites
• Reflects recent use that’s relevant to the current situation
• Links the presence of substance with safety risk
• Allows employers to take appropriate and timely action

Oral fluid testing supports stand-down requirements in reasonable cause and post-incident situations because it provides evidence-based confirmation that an active drug was present, and therefore that a safety risk existed.

Training Is Essential, Not Optional

Testing, however, is only one piece of the puzzle. Employers must invest time and resources into thorough training for supervisors and managers. It’s not enough to rely on test results; supervisors need to be confident in:

• Recognizing the observable signs of substance use
• Documenting those observations accurately and consistently
• Communicating concerns clearly and respectfully with employees

This training is not a one-time event, but rather an integrated component of safety. Through ongoing training, supervisors will be more comfortable deciding when drug and alcohol testing is appropriate, based on real-time behaviours and workplace context. This is the informed, proactive approach that promotes action and makes workplaces safer. 

Creating a Culture of Shared Responsibility

Education shouldn’t stop with supervisors. All employees need to understand:

• What workplace safety risk looks like,
• Why substance use concerns need to be addressed proactively,
• And how the process supports health, safety, and fairness for everyone.

This education supports the Internal Responsibility System (IRS), which is a foundational principle of all Occupational Health and Safety legislation. Everyone has a role to play in protecting workplace safety.

Measuring safety risk isn’t about “catching” someone impaired or doing something illegal. It’s about identifying when someone may not be safe to perform their duties and addressing that concern in a respectful, evidence-based, and focused manner that prioritizes keeping everyone safe.

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