Cannabis and Substance Use in the Workplace: What Employers Need to Know

Dr. Melissa Snider-Adler
MD, CCFP(AM), MRO (AAMRO), DABAM, FASAM, Chief Medical Review Officer, DriverCheck Inc. Physician, Addiction Medicine

Employers continue to face the challenging task of managing cannabis use and substance use in the workplace. This article will dive into the complexities of workplace impairment, offering a comprehensive guide for employers to understand and address cannabis-related issues effectively. 

Understanding Impairment 

Impairment is defined as a decreased ability to perform tasks, which is distinct from intoxication. While intoxication refers to the immediate effects of a substance, impairment can persist long after these effects have subsided, impacting cognitive functions and job performance. In simpler terms, being intoxicated means feeling the immediate "high" from cannabis. In contrast, impairment can mean your thinking, reaction time, or coordination might still be affected even after you no longer feel high. This is important because someone could seem fine but still be unsafe to work. 

Cognitive Effects of Cannabis 

Cannabis use can impair cognitive functions such as executive functioning, attention, memory, and reaction time. Even if an employee does not appear intoxicated, they may still be impaired, especially in safety-sensitive positions where quick decision-making is crucial. 

A percentage of Canadians continue to believe it is safe to drive within two hours of using cannabis, highlighting the ongoing challenge of managing cannabis use and impairment. This underscores the importance of addressing substance use in the workplace, both on the roads and in the workplace. 

Residual Impairment 

Residual impairment is a complex and debated issue where, at times, cannabis effects linger longer than the initial high. This is particularly relevant for heavy, daily users of high-dose THC products, who may not feel the ongoing effects. Still, there is evidence that cognitive impairments may continue to affect their performance and safety at work. Understanding substance use in the workplace helps employers address these lingering effects and maintain a safe work environment. 

Balancing Risk 

Employers must assess the risk of cannabis use in the workplace, determining whether employees are fit for duty. This involves evaluating the potential risks to safety and the well-being of other employees. Each workplace must establish its own risk balance based on specific roles and responsibilities. Substance use in the workplace is a critical factor in this assessment, as it directly impacts the safety and productivity of the work environment. 

Drug Testing Methods 

One of the many ways to manage workplace cannabis use involves drug testing. Various methods include: 

• Hair Testing: Detects use over up to 90 days but not recent use. 

• Urine Testing: Commonly used but detects cannabis weeks after use, complicating recent use detection. 

• Oral Fluid Testing: Effective for recent use detection, typically within 24 hours. 

• Breath Testing: Detects very recent use within a few hours. 

Choosing the right test depends on the workplace's specific needs and policies. 

Managing Positive Test Results 

When an employee tests positive for cannabis, employers face the now what dilemma. A comprehensive approach includes: 

• Understanding Test Results: 

  • Type of Test: Different tests (urine, oral fluid, hair, breath) detect cannabis use over varying timeframes. For instance, urine tests can detect use weeks after consumption, while oral fluid tests are practical for recent use, typically within 24 hours; however, this greatly depends on the screening and confirmation cut-off levels. 

  • Detection Timeframe: Knowing the detection window helps assess the test result's relevance to the employee's current state. 

• Assessing Risk: 

  • Employee's Role: Consider the employee's position and required tasks. Safety-sensitive roles require higher scrutiny due to the potential risks involved. 

  • Test Circumstances: Evaluate the context in which the test was conducted. Was it a random test, a reasonable cause test, or part of a follow-up program? Drug testing should be viewed as a piece of the puzzle, looking at all information to understand the potential risks in the workplace. 

  • Signs of Impairment: Look for signs of impairment, which may not always be obviously visible. Impairment can affect cognitive functions such as attention, memory, and reaction time, even if the employee does not appear intoxicated. 

• Gathering Information: 

  • Employee Interview: Speak with the employee to gather more information about their cannabis use. This can help understand the context and frequency of use. 

  • Further Assessments: Conduct additional assessments if needed, such as a Substance Abuse Professional (SAP) evaluation to determine if there is a substance use disorder that requires attentional support and treatment. 

• Making Informed Decisions: 

  • Balancing Safety: Employers must balance the need for workplace safety with the desire of an employee to use a legal substance outside of work.  

• Policy Adherence: Ensure decisions align with workplace policies and legal requirements. This includes considering the implications of positive test results on employment status and potential disciplinary actions. 

• Connecting the Dots: 

  • Putting Pieces Together: Combine all the information gathered to understand the situation comprehensively. This includes test results, employee interviews, and any additional assessments. 

  • Risk Analysis: Determine the level of risk associated with the positive test result. This involves considering the detection timeframe, the employee's role, the circumstances of the test, and any signs of impairment.  

By taking a thorough and balanced approach, employers can effectively manage positive test results, ensuring workplace safety while supporting employees. This comprehensive strategy helps navigate the complexities of substance use in the workplace, fostering a safer and more productive environment.

Conclusion 

The legalization of cannabis presents significant challenges for employers in managing workplace impairment. By understanding impairment, educating your workforce regarding the risks of use of this legal substance, choosing appropriate testing methods, and taking a balanced approach to risk, employers can create a safer and more productive work environment. Staying informed and proactive is crucial in navigating the complexities of cannabis use in the workplace. 

Employers must also adopt a comprehensive strategy for managing positive test results, which includes understanding test results or asking for help with interpretation, assessing risk, gathering information, and making informed decisions. This approach ensures workplace safety while supporting employees. 

Key Takeaways 

• Impairment differs from intoxication and can persist long after the intoxicating effects have worn off. 

• Employers must balance the risk of cannabis use in the workplace, considering safety and productivity. 

• Cannabis can impair cognitive functions, even if the user does not appear intoxicated. 

• Various drug testing methods have different detection windows and limitations. 

• Residual impairment can be a significant issue specifically for heavy, daily users of high-dose THC products. 

• A comprehensive approach is needed to manage positive test results, balancing safety with employees’ desire to use a legal substance outside work hours. 

• Understanding the type of test and detection timeframe is crucial in interpreting positive test results. 

• Speaking with the employee and conducting further assessments can provide valuable insights into their cannabis use and potential substance use disorder.  

Key Terms 

• Impairment: Decreased ability to perform tasks. 

• Intoxication: Immediate effects of a substance. 

• Cognitive Functions: Mental processes such as attention, memory, and reaction time. 

• Residual Impairment: Lingering effects of cannabis after the initial high. 

• THC: Tetrahydrocannabinol, the psychoactive component of cannabis. 

• Drug Testing: Methods to detect substance use, including hair, urine, oral fluid, and breath tests. 

• Substance Abuse Professional (SAP): A professional who evaluates employees for substance use disorders and provides recommendations for treatment and follow-up. 

Dr. Melissa Snider-Adler
MD, CCFP(AM), MRO (AAMRO), DABAM, FASAM, Chief Medical Review Officer, DriverCheck Inc. Physician, Addiction Medicine