Changes in Testing for Marijuana in the Workplace

Changes in Testing for Marijuana in the Workplace

On August 1st, 2023, Minnesota will become the 23rd state (plus the District of Columbia) to legalize marijuana for adult recreational use. As this trend continues to sweep the United States, many employers are choosing to remove marijuana from their pre-employment drug testing panels. The state of Michigan, for example, is removing marijuana from their pre-employment drug testing for state employees (excepting certain positions, such as law enforcement or heavy machine operators).1

This decision comes partially as a result of relaxed societal attitudes about marijuana usage, but also from employers struggling to fill positions with the current drug testing panels in place.

One of the most concerning aspects of removing marijuana from pre-employment drug testing is the attitude that recreational marijuana use outside the workplace should be treated the "same as alcohol use.” Alcohol is water soluble, while marijuana is fat soluble, with a longer half-life -- and so the drug stays in the body longer. In fact, recent studies show that impairment could last as long as 10 hours after use.2 And even while someone who has used marijuana may not feel like they are impaired, the drug can still be detected in urine tests for up to 30 days, depending on the frequency of use.

Marijuana impairment can have a significant impact on the workplace. The Center for Disease Control (CDC) reported one study from the National Institute on Drug Abuse (NIDA) that found 55% more industrial accidents and 85% more injuries among employees who tested positive for marijuana compared to those who tested negative.4 Marijuana remains a federally schedule 1 controlled substance, which places the drug in the category of "no accepted medical use" with a "high potential for abuse.”5

While some states may be reclassifying marijuana in their drug testing, a drug-free workplace policy's purpose is to help keep employees safe. Employers should review any new statutes and news for their state and, with legal counsel, adjust their policies accordingly.



¹ Connell, Riley. “Michigan No Longer Requires Drug Testing for State Jobs.”, July 12, 2023.

² McCartney, Danielle, Thomas R Arkell, Christopher Irwin, and Iain S McGregor. “Determining the Magnitude and Duration of Acute Δ9-Tetrahydrocannabinol (Δ9-Thc)-Induced Driving and Cognitive Impairment: A Systematic and Meta-Analytic Review.” Neuroscience & Biobehavioral Reviews, January 23, 2021.

3 “How Long Does Marijuana (Weed) Stay in Your System?” American Addiction Centers, September 13, 2022.

4 Howard, John, L. Casey Chosewood, Lore Jackson-Lee, and Jaime Osborne. “Cannabis and Work: Implications, Impairment, and the Need for Further Research.” Centers for Disease Control and Prevention, June 15, 2020.

5 “Drug Scheduling.” DEA, July 10, 2018.