Alcohol vs. cannabis safety: Expert opinion

May 16, 2023

A recent article published in Transport Topics and authored by Eric Miller discussed cannabis safety following the American Trucking Association’s recent Safety, Security & Human Resources (SSHR) National Conference & Exhibition.

“From a safety perspective, marijuana has a much longer period of impairment, different from an occupational perspective than alcohol, and therefore can have a much larger impact on safety,” said Todd Simo, chief medical officer for HireRight at the conference.

According to the results of the 2021 survey by the Substance Abuse and Mental Health Services Administration, 13% of Americans (52 million people) use cannabis.

“We continue to test for [cannabis],” said Tom Lopez, director of corporate safety at FedEx Express. “We have 100% pre-employment testing and continue to use a five-panel test. We went through a long process with the company’s legal team to determine which jobs are safety sensitive. We do have an accommodation process if an applicant tests positive only for marijuana for potential non-safety sensitive jobs openings.”  

While alcohol impairment can be measured by a breathalyzer test, there is currently no reliable and accurate method to test cannabis impairment.

“Unfortunately we’re far away with the available specimens we have,” said Simo. “The gold standard with impairment is blood. But what we’re seeing now with impairment studies is not related to a blood level. So blood is kind of out.”

 According to data published by Transport Topics, the number of truck drivers who tested positive for cannabis use increased by 32% between 2021 and 2022, with almost 41,000 truckers testing positive for THC in 2022. In 2020, the Federal Motor Carrier Safety Administration (FMCSA) created the Drug and Alcohol Clearinghouse to record drug and alcohol infractions received by commercial truck drivers in the US. 

Once a truck driver’s information is entered into the clearinghouse database after failing a drug test, it is necessary for them to complete the return-to-duty process to return to work. However, FMCSA records show that of the 166,000 drivers who failed a drug test and had the failure logged in the clearinghouse, less than 46,000 of them have become eligible to return to commercial truck driving.