June 25, 2019 5:45 PM, EDT

As Marijuana-Use Laws Spread, Drug Still Illegal for Truck Drivers

A display of pre-rolled marijuana cigarettes from Willie's Reserve at a section in a farmers market during a business-to-business networking event, WeedCon West 2019, in Los AngelesA display of pre-rolled marijuana cigarettes from Willie's Reserve at a farmers market in Los Angeles, on June 20, 2019. Though it is gaining acceptance, it is still illegal for truckers to smoke marijuana. (Associated/Richard Vogel)

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Last month, drug-testing firm Quest Diagnostics scientist Barry Sample had a serious warning for U.S. employers: Be on the lookout for marijuana use by your workers. It’s on the rise.

“Our in-depth analysis shows that marijuana is not only present in our workforce, but use continues to increase,” said Sample, Quest’s director of science and technology. “As marijuana policy changes, and employers consider strategies to protect their employees, customers and general public, employers should weigh the risks that drug use, including marijuana, poses to their businesses.”

Indeed, an analysis of 10 million drug tests Quest administered in 2018 concluded that every segment of overall workforce is increasingly flunking lab drug tests for marijuana. Also, Sample noted, attempts to cheat on drug tests are on the rise. Those tested include federal safety-sensitive transportation workers, which include truck drivers.

Barry Sample, Quest Diagnostics' director of science and technology


Although the safety-sensitive group is not broken down by specific jobs, Sample said commercial driver license holders subject to Federal Motor Carrier Safety Administration drug testing make up “the largest chunk” of those within the safety-sensitive workforce group.

Fortunately, the positive test rate for security-sensitive federal employees has not increased as significantly as have other transportation and general workforce employee categories, Quest said. However, for the federally mandated, safety-sensitive workforce urine testing, the marijuana positivity rate grew nearly 5% from 2017 to 2018, and nearly 24% since 2014, according to Quest. That’s a cause for concern, Sample said.

Patrice Kelly, director of the U.S. Department of Transportation’s Office of Drug, Alcohol, and Compliance, said that despite a proliferation of the drug’s nationwide availability and state laws decriminalizing marijuana, she’s confident that the agency’s continued information campaign to remind truck drivers not to use marijuana on or off-duty is largely reaching the audience.

“I attribute that to the fact that we are very clear in our policy statements that medical review officers will not downgrade a positive test result for marijuana, even on the basis that it is medical marijuana,” Kelly said at a recent meeting of a federal policy drug testing advisory board.

Yet, Kelly admits that marijuana issues are “pretty complicated,” largely due to the lack of a legal standard to determine if an individual is impaired using the drug.

Although he has concerns about rising marijuana positivity rates, Sample said he is most concerned about a large spike in post-accident test rates when compared with pre-employment drug tests.

“Historically, they’re relatively comparable,” Sample said. “In 2012, the rate of post-accident drug tests were 2% higher than pre-employment tests. But in 2018, the post-accident rate was 30% to 40% higher.”

Abigail Potter, manager of safety and occupational health policy for American Trucking Associations


“Marijuana legalization in this patchwork across the country is not making it easier for the trucking industry,” said Abigail Potter, manager of safety and occupational health policy for American Trucking Associations. “Drivers are confused. The general public is confused on what is legal and what is not.”

Still, Potter said that past drug-use data have shown that positive drug test rates are lower for truckers than those of the general workforce.

But DOT is quite clear on the subject, Potter said. Truck drivers are not allowed to use marijuana — for recreation or for medical reasons. For other employees in the transportation industry, it can depend on state law and employer requirements, she said. But despite state laws, marijuana remains on the federal government’s Schedule I List of illegal drugs.

“Our recommendation is that if employers are drug testing for marijuana in other than truck driver positions, that employees talk with their in-house counsel and review state law to make sure that they’re meeting all their legal requirements,” Potter said.

Faye Caldwell, a partner in Houston law firm Caldwell Everson, said that 33 states and the District of Columbia have decriminalized the use of marijuana, either for recreational use or for medical conditions. Of that number, only 11 states and D.C. allow recreational use, she said.

However, the specific legal aspects of marijuana vary greatly, she said. While most states prohibit use prior to driving, nearly all do not have specific guidelines for what constitutes impairment, according to Caldwell, who spoke at the drug testing board meeting in May.

But not only is the increasing use of marijuana potentially creating new hazards on U.S. roadways, the drug is fast becoming more potent, according to Charles LoDico, a senior chemist and toxicologist with the U.S. Substance Abuse and Mental Health Services Administration.

“It’s no longer your grandfather’s drug,” LoDico said.

Mexican marijuana sold in the 1980s on average contained 4% of delta-9-tetrahydrocannabinol, or THC, the psychoactive chemical that gives users a high. Today’s pot can contain from 13-20% or higher THC content, LoDico said.

“There is a belief that marijuana is pure and doesn’t harm anybody,” LoDico said. “But in fact, there are known and documented cases of harm.”

The acute effects of marijuana range from impaired short-term memory and difficulty with complex tasks to increased risky behavior and panic attacks, LoDico said.

“Today, the population of the United States that has access to marijuana — medical or recreational — is greater than 90%,” LoDico said. “That should be alarming to all of us.”