Workplace cannabis testing is at the center of a growing national conversation surrounding employee safety, medical cannabis patients, legal off-duty use, and the limitations of current drug-testing methods. MITA USA Founder Demitri Downing recently addressed these issues in an interview featured by The Washington Times.
The article, titled “Report Finds 1 in 5 Workers Testing Positive for Drugs After Increased Marijuana Use,” reported on findings from the 2026 Quest Diagnostics Drug Testing Index. The data showed that 19.1% of workers tested through hair analysis in 2025 received a positive drug-test result, with marijuana identified as the primary driver of the increase.
The findings have renewed an important national conversation: how should employers protect workplace safety while recognizing the limitations of cannabis testing and the legal use of marijuana outside working hours?
In his comments to The Washington Times, Downing emphasized that employees must arrive at work capable of performing their responsibilities safely and effectively, particularly in safety-sensitive roles.
Operating heavy machinery, driving commercial vehicles, performing surgery, managing financial responsibilities, and completing other high-risk tasks require sound judgment, attention, and competence. When an employee is impaired, creates a safety risk, or is unable to perform essential duties, employers have a legitimate responsibility to intervene.
Cannabis, Downing explained, should not receive an automatic exemption from the same workplace standards applied to alcohol or other impairing substances.
At the same time, workplace policies must distinguish between actual impairment and evidence that an individual used cannabis at some point in the past.
One of the central challenges surrounding cannabis testing is that many commonly used testing methods detect previous exposure rather than present impairment.
Hair testing can identify cannabis use over an extended period, often approximately 90 days. A positive hair-test result may therefore indicate that an individual consumed cannabis weeks or months earlier, but it does not necessarily establish that the individual was impaired at work, impaired during an accident, or unable to perform job responsibilities.
This distinction becomes especially important as more states recognize legal adult-use cannabis and medical cannabis programs.
Downing cautioned against treating a chemical result as definitive evidence of workplace misconduct without considering the timing of consumption, employee behavior, job performance, safety concerns, and the limitations of the testing method.
“Protect workplace safety aggressively. Just do not confuse a chemical history lesson with proof of present impairment.”
The Quest Diagnostics findings are significant, but the way those findings are interpreted matters.
A positive hair-test result among tested workers is not equivalent to evidence that the same percentage of American employees are arriving at work impaired. The data measures the presence of substances within a particular detection window; it does not independently determine when the substance was consumed or whether it affected the employee’s performance.
Effective workplace cannabis policies should therefore distinguish among:
Downing’s position is that employees do not have a right to perform their jobs while impaired, particularly when their responsibilities affect the safety of coworkers, customers, patients, or the public.
However, employers should also avoid assuming that any positive cannabis result is automatic proof that an employee was impaired while working.
The conversation is also more complicated for patients who use cannabis as part of an ongoing medical treatment.
Medical cannabis patients may consume cannabis lawfully to manage symptoms or maintain their quality of life. Their status as patients does not excuse dangerous workplace behavior or impairment in safety-sensitive situations, but it does underscore the need for policies that consider individual circumstances rather than relying exclusively on historical detection.
Employers, policymakers, laboratories, and industry leaders must continue working toward more reliable standards for identifying current impairment while respecting medical use, legal off-duty behavior, workplace responsibilities, and public safety.
Cannabis policy is evolving rapidly across the United States, but testing technology and workplace regulations have not always evolved at the same pace.
Unlike alcohol testing, which can often provide evidence related to current intoxication, cannabis testing frequently identifies metabolites or previous consumption without conclusively determining whether an individual is impaired at the time of testing.
As cannabis laws continue to change, employers will need policies that are clear, consistent, science-based, and appropriate for the risks associated with each position.
MITA USA supports informed conversations that recognize both sides of the issue: workplaces must be safe, and testing standards must accurately reflect what the results can and cannot prove.
Through media engagement, education, and collaboration with industry stakeholders, MITA USA will continue contributing to discussions surrounding responsible cannabis use, patient protections, workplace policy, public safety, and the evolution of the legal cannabis industry
Read the article in The Washington Times