As more states legalize marijuana, the Department of Transportation looks to change drug testing policies
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As more states legalize marijuana, the Department of Transportation looks to change drug testing policies

Drug tests for marijuana use continue to reflect a bygone zero-tolerance approach and fail to reliably detect on-duty use and intoxication.

Three decades ago in response to deadly transportation accidents arising from drug and alcohol intoxication, Congress passed a law requiring “safety sensitive” interstate transportation workers to be screened for workplace drug and alcohol use. Since then, one of the covered substances—marijuana—has been increasingly decriminalized by state and local jurisdictions across the country. 

Despite marijuana’s alcohol-like legal status in many states, transportation worker drug tests for marijuana use continue to reflect a bygone zero-tolerance approach and fail to reliably detect on-duty use and intoxication. This policy mismatch is unnecessarily straining the critical transportation workforce at a time when supply chains are already overwhelmed. At a minimum, the federal government should modernize federal transportation drug testing requirements to eliminate pointless burdens on the transportation sector. 

In recent years, a majority of states have legalized medical marijuana and 18 states (plus Guam and the District of Columbia) have legalized adult recreational use of marijuana. In addition, 14 states plus the District of Columbia generally prohibit employers from discriminating against employees who use medical marijuana and test positive for marijuana on a drug test (Nevada and New Jersey prohibit employment discrimination for recreational use as well). 

There are a few exceptions to these state anti-discrimination laws, but the most significant relate to federally regulated transportation occupations. This is because of the Omnibus Transportation Employee Testing Act (OTETA) of 1991, which requires safety-sensitive employees in air, rail, road, and public transportation to submit to pre-employment and workplace screening for alcohol and federally controlled substances determined by the Secretary of Transportation. Those drugs specified in the Code of Federal Regulations (49 C.F.R. § 40.3) are marijuana, cocaine, amphetamines, phencyclidine (PCP), and opioids. 

Unfortunately, while the law was aimed at improving safety by preventing on-duty drug and alcohol use and intoxication, the approved OTETA test for marijuana use is an extremely imprecise method for detecting intoxication. Under current regulations, laboratories test urine specimens for the presence of marijuana metabolites (49 C.F.R. § 40.85), which can be detected days or even weeks after marijuana intoxication—and the danger associated with intoxicated transportation workers—has subsided. OTETA testing for marijuana thus primarily serves as a mechanism for generating false positives for marijuana intoxication.

This inaccurate marijuana intoxication testing has practical consequences. The Federal Motor Carrier Safety Administration (FMCSA), which regulates truck and bus drivers, reported in a January 2022 drug and alcohol summary report that its OTETA testing detected marijuana in 31,085 (64%) of 48,770 total positive drug tests in 2021. The majority of these positive tests occurred at pre-employment screening, although random workplace screening wasn’t far behind. Under current OTETA drug testing policies, more than 83,000 people with commercial driver’s licenses or commercial learner’s permits are currently prohibited from driving. This is roughly the same number as the truck driver shortage of 80,000 drivers estimated by the American Trucking Associations in 2021. And FMCSA isn’t alone with marijuana playing an outsized role in positive OTETA drug tests. The Federal Transit Administration reported that it detected marijuana in 77% of its positive drug tests in 2020.

If marijuana were still universally prohibited in the U.S., the extreme imprecision of urine testing for marijuana could perhaps be justified on misguided zero-tolerance grounds. And to be sure, marijuana remains a federally prohibited Schedule I controlled substance. But times have changed and federal regulations should be amended to accommodate new, more precise test methods for marijuana intoxication if marijuana is to remain on the list of five controlled substances tested under OTETA.

It’s important to note that OTETA does not require that the Department of Transportation rely on urine testing for marijuana use. Nor does OTETA require the Department of Transportation to test for marijuana at all. The selection of the five controlled substances and how they are tested is at the discretion of the secretary of transportation. In fact, current Department of Transportation drug testing regulations explicitly prohibit laboratories from testing “‘DOT specimens’ for any other drugs” than those five controlled substances selected by the secretary of transportation (49 C.F.R. § 40.85).

But in practice, the secretary of transportation isn’t interpreting OTETA and implementing it in a vacuum. Despite the broad discretion the Department of Transportation possesses related to transportation workforce drug and alcohol testing programs, it has long followed the Substance Abuse and Mental Health Services Administration (SAMHSA, an agency of the Department of Health and Human Services) mandatory guidelines for laboratory and specimen testing procedures. Since 1988, these guidelines have required that only urine specimens be collected and tested, with all the associated limitations of urinalysis in detecting recent use and intoxication, especially for marijuana.

In 2015, SAMHSA proposed updating the mandatory guidelines to permit oral fluid (saliva) testing. In contrast to the days and weeks following intoxication that marijuana can show up on urine tests, oral fluid tests generally do not detect marijuana use from more than 1-3 days prior. In the final mandatory guidelines that became effective January 1, 2020, SAMHSA estimated that if the Department of Transportation adopted the latest mandatory guidelines for its OTETA drug testing programs, oral fluid testing would displace 1.5 million to 1.8 million urine specimens per year after four years. This equates to 25-30% of total test specimens collected each year under federal transportation drug and alcohol programs. Such a change could significantly reduce marijuana intoxication false positives, the disciplinary consequences to transportation workers, and the impact of labor shortages on the transportation sector.

The good news is that in February 2022, the Department of Transportation published a notice of proposed rulemaking to revise its drug and alcohol regulations to reflect the current SAMHSA mandatory guidelines. Public comments are due April 29.

While adopting an oral fluid testing alternative to urinalysis wouldn’t eliminate OTETA’s false positives for on-duty marijuana intoxication, it would surely be an improvement over the status quo. Federal policymakers must continue to grapple with the expanding legal marijuana markets in the states and what they mean for outdated zero-tolerance policies.