Missouri Amendment 2 passed on Election Day 2018, legalizing the use of medical cannabis for qualifying patients. At the time, Missouri was one of 33 states permitting its use. As of February 2025, medical cannabis is now legal in 39 states. However, this shift in legalization raises important questions about medical cannabis in the workplace, workplace safety and compliance.
In this Ask the Expert, I’ll answer employers’ most frequently asked questions about the effects of medical cannabis on workplace safety and productivity.
RELATED: An Employer's Guide to Substance Abuse Policies >>
Employers cite safety as one of their top concerns when evaluating the impact of medical cannabis and employment policies. Marijuana affects the central nervous system, altering sensory perception, thought formation, short-term memory and cognitive processing.
Physically, it impairs motor coordination, balance and reaction time. Some individuals may also experience hallucinations, anxiety or panic attacks.
According to the Occupational Safety and Health Administration (OSHA), multiple studies link cannabis use to an increased risk of workplace injuries.
Research suggests that positive cannabis tests after workplace accidents have risen steadily since legalization. In 2023, post-accident cannabis positivity in the U.S. workforce reached 7.5%, the highest rate on record.
Further research into cannabis’s effects on workplace safety reveals that cognitive impairment can last up to 10 hours, depending on consumption method and potency. A prescription for medical cannabis does not grant an employee the right to compromise workplace safety.
Marijuana impacts various physical and cognitive functions critical to workplace safety. Some of the most concerning effects for employers include:
These limitations pose significant safety risks, particularly in industries that require operating machinery, driving or handling hazardous materials.
RELATED: Drugs on the Job - What Employers Should Know About Opioids in the Workplace >>
No. According to Fisher Phillips, Missouri law explicitly prohibits public cannabis consumption in any form, including smoking, vaping, edibles or oils. Workplace policies should clearly outline this restriction to ensure compliance and minimize liability.
Yes, Missouri employers can still maintain a drug-free workplace, even if some employees have medical marijuana prescription cards.
Fisher Phillips explains, “Amendment 2 provides a safety net for employers, prohibiting employees from filing claims against Missouri businesses for wrongful discharge, discrimination or similar actions based on the employer prohibiting the employee from being under the influence of marijuana while at work or disciplining the employee for working or attempting to work while under the influence of marijuana.”
Additionally, employment and medical cannabis regulations apply to specific industries:
RELATED: Drug Tests - Four Questions to Ask Before Dropping Your Program >>
No. Since cannabis remains illegal under federal law, it is not covered under the Americans with Disabilities Act (ADA). Even in states where medical cannabis is legal, employers are not required to accommodate its use.
With evolving attitudes and laws surrounding medical cannabis, employees may underestimate cannabis’s risks. However, when it comes to employment policies and medical cannabis, workplace safety remains paramount. Employers should proactively update policies, educate employees, and enforce safety regulations to mitigate risks.
Axcet HR Solutions is your trusted partner for navigating workplace safety and compliance in a changing legal landscape.
This content is for informational purposes only and does not constitute legal advice. For specific legal concerns, consult a qualified attorney familiar with employment law and medical cannabis regulations.
Written by
Rob Eckwall is a Saf
Rob Eckwall is a Safety and Health Consultant at Axcet HR Solutions, where he partners with businesses to create safer workplaces, reduce risk, and maintain compliance with evolving safety and regulatory standards. He works directly with client companies to evaluate work environments, identify potential hazards, and implement practical, effective safety programs that protect employees and support business operations.
Rob's approach is hands-on and proactive. He conducts on-site safety assessments, develops customized safety and health programs aligned with OSHA requirements, and provides coaching to leadership teams on building and maintaining compliant, safety-focused workplaces. He also supports clients through OSHA inspections, citation responses, and abatement efforts—helping them navigate complex regulatory situations with confidence.
In addition, Rob investigates workplace incidents to determine root causes and prevent recurrence, prepares detailed reports with actionable recommendations, and designs training programs that equip employees with the knowledge and tools to work safely. His focus is not just on compliance, but on creating sustainable safety practices that become part of a company's culture.
Rob is known for his collaborative, solutions-oriented style and his ability to translate complex safety requirements into clear, actionable steps. Through his writing, he shares practical insights and real-world strategies to help employers improve safety outcomes, reduce workplace incidents, and build stronger, more resilient organizations.
ety and Health Consultant at Axcet HR Solutions, where he partners with businesses to create safer workplaces, reduce risk, and maintain compliance with evolving safety and regulatory standards. He works directly with client companies to evaluate work environments, identify potential hazards, and implement practical, effective safety programs that protect employees and support business operations. Rob’s approach is hands-on and proactive. He conducts on-site safety assessments, develops customized safety and health programs aligned with OSHA requirements, and provides coaching to leadership teams on building and maintaining compliant, safety-focused workplaces. He also supports clients through OSHA inspections, citation responses, and abatement efforts—helping them navigate complex regulatory situations with confidence. In addition, Rob investigates workplace incidents to determine root causes and prevent recurrence, prepares detailed reports with actionable recommendations, and designs training programs that equip employees with the knowledge and tools to work safely. His focus is not just on compliance, but on creating sustainable safety practices that become part of a company’s culture. Rob is known for his collaborative, solutions-oriented style and his ability to translate complex safety requirements into clear, actionable steps. Through his writing, he shares practical insights and real-world strategies to help employers improve safety outcomes, reduce workplace incidents, and build stronger, more resilient organizations.
.png){kind=logo}
.webp)
Let us know what you think...