Why Employers Should Continue Testing for Marijuana: The Safety Case Amid Legalization

Marijuana Legalization and Workplace Safety

As more states legalize marijuana, employers face a challenging question: Should they continue testing employees for cannabis use? While some argue that legalization should end workplace testing, the historical safety evidence tells a more complex story. For employers, especially those managing safety-sensitive positions, continuing marijuana testing remains an important tool for protecting workers and the public.

The Safety Risks of Marijuana Use at Work

When marijuana use increases in the workplace, safety risks follow. According to the National Institute on Drug Abuse (NIDA), eEmployees who test positive for marijuana have 55% more industrial accidents, 85% more injuries, and 75% greater absenteeism compared to those who test negative.

And those dangers extend beyond the workplace: Studies consistently show that cannabis use nearly doubles the risk of car crashes, a troubling statistic for employers in safety-sensitive industries.  

Cannabis impairs the cognitive and motor skills needed for safe work. Marijuana causes sedation, disorientation, impaired judgment, lack of concentration, and slowed fine motor skills. These effects can delay decision-making and harm memory and attention, which are essential skills for nearly every job.  

Why Timing Matters in Marijuana Drug Testing: Off-Duty Use Still Matters

Some opponents of marijuana testing point out an issue with traditional urine drug tests: THC, the psychoactive ingredient in cannabis, stays in the body for days or even weeks after use. However, standard urine tests detect metabolites, which are inactive byproducts, not active THC. This means traditional testing can flag workers who are completely sober and capable of working safely.

One solution may be Oral fluid testing. Oral fluid testing can detect recent drug use within approximately 24 to 48 hours, which better matches the actual window of impairment. Additionally, marijuana's impairment effects typically last between 3 to 10 hours, and saliva testing is far more reliable at capturing this timeframe than urine tests are.  

Combining Drug Testing Methods for Better Safety Outcomes

Consider combining testing methodologies, such as oral fluid with hair testing, to increase your window of detection and create a more comprehensive screening approach that catches impairment across different timeframes.

Marijuana Testing for Safety-Sensitive Positions

Many states that have legalized marijuana still recognize that certain jobs demand special protections. States like Oklahoma, New Mexico, and Iowa have carved out exceptions for safety-sensitive positions, where impairment can cause immediate danger. These positions typically include the following:

• Operating motor vehicles or heavy equipment
• Handling hazardous materials
• Providing medical care
• Working at heights or in confined spaces
• Carrying firearms
• Supervising other employees

For these roles, continued testing is less about punishing recreational use, and much more about preventing tragedies. Employers and employees in safety-sensitive industries face higher costs, both financial and otherwise, when substance abuse occurs.

Federal Marijuana Testing Requirements Still Apply

Employers also need to understand that federal law has not changed, even as individual states legalize marijuana. Federal contractors, companies receiving federal funding, and workers in federally regulated industries (like transportation and aviation) are still required to test for marijuana.  

A Smarter Approach to Marijuana Testing at Work

The right path forward isn't to abandon testing entirely. Instead, employers should embrace smarter testing methods.  

By switching to oral fluid testing for safety-sensitive positions, employers can detect recent use that might impair performance while avoiding penalties for responsible off-duty consumption.

Additionally, employers should also pair testing with clear policies that

• distinguish between off-duty use and impairment at work;
• focus on safety-sensitive positions where risks are highest;
• use more accurate testing methods when possible; and
• provide education about marijuana's real impairment risks.

The Bottom Line on Marijuana Testing and Workplace Safety

Marijuana legalization doesn't mean marijuana impairment disappears: Impaired workers still cause more accidents, more injuries, and more harm. For employers managing safety-sensitive positions or those subject to federal requirements, continuing to test for marijuana is simply the responsible move.

But employers need to honor both worker privacy and workplace safety: By choosing the right testing methods and applying policies fairly, employers can honor both.

Join Us at DISA's S3 Conference

Ready to dive deeper into workplace safety and compliance strategies? DISA's S3 Conference brings together industry leaders, HR professionals, and compliance experts to discuss the latest trends in occupational health and safety.  

Learn from experienced practitioners, network with peers facing similar challenges, and discover innovative solutions for managing workplace safety in today's evolving landscape. Register now to secure your spot at this must-attend event for employers committed to protecting their workforce.