Cannabis and the Workplace

April 23, 2026: Department of Justice announced FDA-approved cannabis products and products containing cannabis subject to a Qualifying State-issued License are immediately moving from Schedule I to Schedule III of the Controlled Substances Act. For current information on marijuana rescheduling, see the U.S. DEA proposed rule, Schedules of Controlled Substances: Rescheduling of Marijuana.

Cannabis and Workplace Safety: What Employers Need to Know

Cannabis products are becoming more common in the United States. At the same time, laws and products are changing quickly. This can make it hard for workers and employers to understand what cannabis is, which products may cause impairment and why cannabis use matters for workplace safety. This page is designed to explain the basics: what common cannabis-related terms mean, how different products may affect the brain and body, and why impairment can create safety risks on the job.

● In Quest Diagnostics’ 2025 Drug Testing Index, marijuana was the most frequently detected drug in workplace testing
● One study found 10.7% of U.S. workers reported using cannabis in the past 30 days
● Post-accident marijuana positivity was 7.3% in 2024, showing why employers continue to focus on impairment and safety

Cannabis is a plant that contains many chemical compounds called cannabinoids. These compounds can affect the brain and body in different ways. Some cannabis-related products can cause impairment or other mind-altering effects. The main psychoactive chemical in cannabis is tetrahydrocannabinol (THC). Our brains have neuroreceptors that respond to THC-like chemicals. When a person uses cannabis these receptors activate, causing brain and body changes. The effects of cannabis vary greatly and may happen quickly or slowly, depending on how people use it (smoking, vaping, ingesting) and body make up (height, weight, metabolism, tolerance). Cannabis can impact reaction time, short-term memory and motor skills, and can lead to increased risk-taking and poor judgment.

Cannabis can be used in different ways, and the way a person uses it can change how quickly effects begin and how long they last:

● Smoking or vaping: Effects often begin within minutes, which can lead to more immediate impairment
● Edibles: Effects are often delayed 30 minutes to 2 hours, so people may take more than intended, increasing the risk of stronger or longer-lasting impairment
● Other products: Cannabis may also be found in oils, drinks, tinctures, concentrates and other products; these can vary widely in strength and effect

Cannabis can impair cognitive and motor functions critical for safe work performance, including attention, reaction time and judgment. These risks may be especially significant in safety-sensitive roles, such as transportation, construction, manufacturing and health care.

Depending on the product, dose, person and timing, cannabis may:

These effects may create greater safety concerns in jobs that involve driving, operating equipment, working at heights, handling patients, making safety-critical decisions or doing other high-risk tasks. At the same time, traditional drug testing approaches do not reliably measure real-time impairment because cannabis compounds can remain detectable in the body long after the impairing effects have subsided. For these reasons, many organizations are shifting toward risk-based and impairment-focused approaches that emphasize workplace safety, clear policies and education.

As cannabis legalization expands, employers are navigating complex and evolving workplace implications:

Changing Legal Landscape
Cannabis laws vary widely by state, including differences in medical use, recreational use and employee protections. Employers must ensure workplace policies align with applicable federal, state and local laws.

Safety and Impairment Risks
Cannabis may impair coordination, reaction time and decision-making, which can increase safety risks in certain work environments. Impairment levels can vary based on dose, potency, method of consumption and individual tolerance. 

Detection and Testing Challenges
Unlike alcohol, cannabis testing typically detects past exposure rather than current impairment. THC compounds can remain detectable for days or weeks after use, making it difficult to determine whether a worker is impaired at the time of testing. 

Safety-Sensitive Roles
Federal regulations still prohibit cannabis use for workers in certain regulated industries, including many transportation roles governed by U.S. Department of Transportation regulations.