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Workers Compensation Issues

Cannabis in the Workplace

Joe Galusha | November 8, 2019

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Medical marijuana on a prescription pad

Cannabis use is not new; however, its acceptance as a treatment for certain medical conditions and side effects, along with the recent passage of legislation legalizing recreational cannabis in Michigan, has forced employers to consider how personal choices to use cannabis may affect work rules and operations. Alcohol influence, long a part of the occupational equation, has established testing protocols and clear behavioral indicators of impairment. Cannabis is, quite frankly, relatively uncharted territory in the workplace.

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*Iowa - use of CBD oil only

Much of what is known about the effects of cannabis is anecdotal due (until recently) to its illegal status. The scientific and medical conclusions available are confusing as they reveal both beneficial and negative impacts that often contradict each other. Consequently, evidence can be found to support both sides of the debate. What is not in dispute, as is the case for most drugs—legal or otherwise—is that cannabis may impact the behavior of the user operating vehicles and hazardous equipment. Employers are responding to the "new reality" of cannabis legalization in the context of the challenges it represents for their workplaces.

Challenges in the Workplace

When does personal choice override providing a safe and productive workplace, and how does legalization affect drug policies? As an example, the construction industry historically has been diligent and especially cognizant of the challenges of maintaining a drug-free workplace. Operation of heavy equipment, hazardous tools, dangerous work areas, and operations are generally deemed "safety sensitive" and require full attention to the task. In addition, companies with federal contracts are required to have a zero-tolerance policy for both their own and their subcontractors' employees. It is also typical for construction companies to work in multiple states with differing legislation regarding cannabis. This adds to the difficulty of finding qualified employees who will not test positive on preemployment and random testing.

These thoughts were echoed by Paul Wrzesinski, safety director for the Associated General Contractors, based in Lansing, Michigan, a state where cannabis has recently been legalized. According to Mr. Wrzesinski, "The challenge will be finding and hiring drug-free workers who can pass the preemployment screening." Most companies he works with are sticking with their zero-tolerance programs as there are currently no legal determinations of what constitutes "under the influence" for cannabis (unlike alcohol).

In fact, conversations with several employers across multiple industries in Michigan revealed a common concern that determining impairment poses a significant dilemma for their companies. Zero-positive testing appears to be the consensus as to the safest course of action until corroborated testing is developed and impairment is legally defined.

Mr. Wrzesinski cites, as an example, a crane operator climbing to their perch 20 floors above the ground and remaining there for an entire shift. In this situation, even the slightest possibility of impairment could have potentially disastrous consequences.

David Woods, industrial hygiene manager for Michigan-based Fibertec, says the company has had a zero-tolerance drug and alcohol policy in place for quite some time. "It [marijuana] is an illegal drug as far as we are concerned; between federal work and client requirements, we are not going to make any changes." They also require a 5-panel testing protocol for lab personnel and 10-panel protocol for the geo-probe division. 

With regard to the impairment issue, coauthor Sheila Ide suggests that companies that do not have zero-tolerance policies or normally perform preemployment or random drug tests typically have a postaccident testing policy that applies when accidents appear suspicious or there is documented observance of unusual/suspicious behavior. However, these policies are proving difficult to enforce. Traditional postaccident drug testing focused on identifying the presence of illegal substances or the level of alcohol in the blood also has been somewhat problematic. In states where recreational cannabis use is legal, testing simply for the presence of tetrahydrocannabinol (THC) does not necessarily correlate to impairment.

Outside of an observation of unusual behavior or a positive drug test, there is no certifiable definition for being under the influence of cannabis. A February 22, 2019, article by Amy Biolchini of the Kalamazoo Gazette, "Marijuana Most Prevalent Drug in Michigan Roadside Testing, Police Find," however, reported on the results of a 2018 pilot program of a new testing method for determining impairment. According to Ms. Biolchini, the Michigan State Police (MSP) completed a 1-year study in 5 counties to roadside test drivers suspected to be driving under the influence of drugs. Of the 92 drivers tested, 89 were arrested with over 70 positives for cannabis. "The oral fluid roadside test instrument correlated well with independent lab results and/or evidentiary blood test results," according to MSP Special First Lt. Jim Flegel. The testing recognizes many drugs in addition to cannabis and opioids and gives a reading in a few minutes. Due to the success of the pilot program, the study is going to be extended statewide. Consequently, regardless of the legality of marijuana possession and use, driving under the influence is still illegal and may lead to arrest and conviction.

Research on making impairment determinations based on THC blood and saliva levels is ongoing but is currently not definitive. A recent article by Linda Johnson in Canadian Occupational Safety states: "From an employer's perspective, it's really a case of choosing an arbitrary presence of THC or CBD in the system. And, regardless of what presence is chosen, that won't necessarily confirm impairment, and it definitely won't confirm impairment at a particular point in time…. You can test for whether there's a presence of cannabis in a person's system, but what impact that cannabis has had on the person's mental state is still up in the air. That's the challenge." 1

Ms. Johnson adds that new app-based technologies may provide an answer for impairment testing. As an example, one app requires a dot to be followed as it moves around the screen to calculate degree of impairment. This type of approach does not focus on the cause of impairment but rather the level. However, its efficacy is currently not supported by independent research.

Policy Suggestions

The following are some considerations when creating or reviewing a drug and alcohol policy. 

  • Review all policies, collective bargaining agreements, job descriptions (determining safety sensitive), human resources manuals, handbooks, regulations, work rules, and contracts in the context of the new cannabis laws.
  • Ensure appropriate wording on alcohol and drug use is addressed.
  • Create a clear statement affirming that it is against company policy to consume or possess alcoholic beverages or cannabis on company property or to report to work impaired or under the influence of alcohol or drugs.
  • Create a clear statement that the possession, use, sale, or consumption of alcohol, cannabis, or any controlled substance or illegal drug (as defined by state or federal law) while on company property or during the course and scope of employment is prohibited.
  • Create a statement that an employee who is consuming medication under the supervision of a healthcare provider that may affect or impair the employee's ability to safely or competently perform his or her job must inform his or her supervisor of the situation.
  • Include a summary of the policy for preemployment, random, postaccident, or reasonable suspicion testing for drugs or alcohol. Check state law regarding cannabis testing, as states and cities have begun to forbid such testing during the preemployment process.
  • Explain consequences for positive results.
  • Conduct training that makes managers more likely to enforce the policy. The training should include supervisors, managers, and employees and cover all aspects of the policy. Additionally, conduct supervisory awareness training for signs and symptoms of impairment.

Those positions covered by the Department of Transportation Rule 49CFR 40, section 40.1 (Federal Motor Carrier, Federal Railroad Administration, Federal Aviation Administration, and Pipeline or Natural Gas Operations), have explicit requirements for testing, training, and consequences.

Finally, it is also important to provide access to support for employees with drug problems, which can range from a formal assistance program to a referral to local services. Employers might also consider establishing a self-reporting rule that employees report any drug-related convictions.


The surge of changing state laws regarding cannabis is likely to continue in the foreseeable future. It appears a virtual tipping point has been reached with regard to the social acceptance of cannabis that is unlikely to revert. While the long-term impact has yet to be determined, organizations in affected states need to take a serious look at their policies, refresh them as necessary, and retrain supervisors on this new reality in the workplace.

Thanks to Sheila Ide for her insight on this article. Ms. Ide is the president and a board member of the Michigan Safety Conference and has spent more than 35 years as a safety administrator and human resources director before becoming an independent consultant and speaker for safety and personnel topics. As deputy personnel director at the city of Lansing, she developed the city's first commercial driver's license and drug and alcohol training and testing programs in accordance with Department of Transportation regulations. She has authored several training modules, newsletters, and articles for trade journals, local news, and Michigan Occupational Safety and Health Administration (OSHA) publications. Ms. Ide was instrumental in the development of and facilitated the first 7 years of the Michigan OSHA Training Institute, offering Michigan workers and employers more than 45 safety, health, construction, and management topics.

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