The U.S. Department of Health and Human Services last week sent the U.S. Drug Enforcement Agency (DEA) a recommendation to reclassify marijuana under the Controlled Substances Act from Schedule I to Schedule III, a move that represents a major shift in U.S. federal drug policy.

If enacted, marijuana use would still be illegal at the federal level. However, the proposed reclassification to Schedule III is expected to free up funding for research on human health effects, expand access for medicinal use, and allow state-regulated marijuana industry operators to write off standard expenses and lower their tax burden.

Drug Schedules

Schedule I, II and III drugs are differentiated based on their potential for abuse and medical use:

• Schedule I drugs have the highest potential for abuse and no accepted medical use. They include marijuana, heroin, LSD, ecstasy (MDMA) and peyote.
• Schedule II drugs have accepted medical uses and a high potential for abuse. Examples include opioids, stimulants and certain depressants.
• Schedule III substances have lower potential for physical and psychological dependence and certain accepted medical uses with a prescription. Examples include anabolic steroids, ketamine, codeine preparations, certain substances used for opioid addiction treatment, as appetite suppressants and for cancer patients undergoing chemotherapy.

What’s Next?

The proposed reclassification must be reviewed and signed off on by the White House Office of Management and Budget and returned to the DEA for a public comment period. According to reports, the DEA will evaluate comments and draft a rule for review by an administrative law judge. After the administrative law review, a final version of the rule will be published. It is not clear how long the process may take or when the change might take effect.

Cannabis Effects

The cannabis plant contains more than 100 compounds (or cannabinoids). These include tetrahydrocannabinol (THC), which induces a high, and cannabidiol (CBD), which does not contain psychoactive components. Non-psychoactive cannabis metabolites are stored in the body after THC is metabolized. Metabolites detected on a drug test indicate that marijuana was consumed sometime in the last few weeks and are not a definitive indicator of current impairment. The U.S. Food and Drug Administration has approved one prescription medication that contains a purified form of CBD and two medications made from a synthetic chemical that mimics THC.

Studies show that psychoactive components may affect memory, concentration, learning and decision-making capabilities, physical coordination, reaction times and emotional stability. They can also increase heart rate and blood pressure. Marijuana smoke can damage lungs.

Legal Overlaps

Overlaps between state and federal laws governing the use of marijuana can be tricky for employers to navigate. Medical use of cannabis is legal in 40 states and the District of Columbia; recreational use is allowed in 24 states and Washington, D.C. State laws do not pre-empt federal laws that require applicants or employees to be tested for controlled substances as a condition of employment, for employers to receive federal funding or federal licensing-related benefits, or for employers to enter into a federal contract. Employers with safety-sensitive positions typically have zero-tolerance policies.

Effective Jan. 1, 2024, California and Washington became the first states in the country to provide protections for individuals who test positive on workplace drug tests for non-psychoactive cannabis metabolites in urine, hair, blood or other bodily fluids. Both states determined that drug tests should focus only on the presence of psychoactive components. Some employers may opt to rely on observations of performance and conduct in lieu of drug test results.

Potential Consequences

WorkCare Vice President Jeffrey Jacobs, M.D., M.P.H., a WorkCare occupational physician and Medical Review Officer (MRO), sees advantages and disadvantages to the proposal. On one hand, Schedule III reclassification appears to support expanded medical research and greater allowance for appropriate medicinal uses. On the other hand, he said, “it doesn’t appear to promote workplace safety or society safety. There is enough recent evidence since legalization that there are more injuries and accidents occurring that marijuana plays a role in.”

If the DEA’s move to reclassify THC as a Schedule III drug is finalized, “it will be interesting to see how the change affects Department of Transportation (DOT) drug testing as well as how those changes may trickle down to non-regulated testing,” said Sarah Johnson, M.D., M.P.H., a WorkCare Associate Medical Director and experienced MRO. “With the new laws in California and Washington, we are already seeing restrictions on employers’ options for maintaining a drug-free workplace. I expect that the reclassification of THC will lead to more states adopting similarly restrictive laws, which could lead to an increase in safety incidents in the workplace.”

Connections between marijuana use and workplace incidents are already evident. For example, in one controlled study, legalization of recreational marijuana was associated with a 10 percent increase in workplace injuries among those aged 20 to 34, according to findings published in JAMA Health Forum. When only full-time workers were included in the data, there was an 11.9 percent uptick in injury rates.

In a Canadian study, researchers evaluated the relationship between past-year cannabis use and the risk of workplace injury, differentiating workers who used cannabis before and/or at work (workplace use) from those who only used it outside of work (non-workplace use). Use in the workplace was associated with a nearly two-fold increase in injury risk, while a relationship between non-workplace use and workplace injury was not found.

According to Quest Diagnostics, which tested more than 6.3 million post-accident specimens in 2022, 7.3 percent of workers tested positive for cannabis immediately after an incident, the highest rate in 25 years. In a 10-year time frame from 2012 to 2022, post-accident marijuana positivity increased by 204 percent. Quest Diagnostics also reported that increases in post-accident marijuana correlated with legalization of marijuana in certain states. The highest rates of positive tests were found in retail trade, accommodation and food services, wholesale trade, and administrative support, waste and remediation service sectors.

To learn more, refer to WorkCare’s fact sheet on recreational marijuana use protections. Contact our Medical Exams & Travel drug testing team for related medical and compliance guidance here.