Federal: Transportation Department Finalizes Rule Authorizing Oral Fluid Drug Testing

Washington, DC: Officials with the US Department of Transportation have finalized a new rule authorizing commercially licensed drivers the option to undergo oral fluid testing as an alternative to urinalysis.

“This additional methodology for drug testing will give employers a choice that will help combat employee cheating on urine drug tests and provide a less intrusive means of achieving the safety goals of the program,” the agency stated in an announcement in the Federal Register.

The forthcoming rule will set a 4 ng/ml cutoff limit for the presence of THC in saliva. The effective date of the new rule is June 1, 2023. However, use of oral fluid testing cannot begin until the US Department of Health and Human Services certifies at least two laboratories to perform saliva screening. To date, no labs have received HHS certification.

Federal transportation laws currently mandate that commercially licensed drivers randomly undergo marijuana urinalysis testing, which detects the presence of the inert carboxy-THC metabolite. The non-psychoactive metabolite is detectable in subjects’ urine for weeks or even months following past exposure.

Since 2020, over 100,000 truck drivers have tested positive for past exposure to marijuana. Those who fail their test are required to enter a ‘return to work’ program, which includes passing a drug test, in order to have their license reinstated. However, only about one-quarter of those with drug test failures have done so – resulting in driver shortages and supply chain issues.

Saliva testing typically identifies residual traces of THC for up to 24 hours following marijuana exposure, a period of time beyond the window of cannabis-related impairment, but one that is far shorter than the timeline associated with urine testing or blood testing

“While oral swab tests do not necessarily correlate with impairment from cannabis, they are a better predictor of recent use than are urine tests, which can pick up inactive THC metabolites days or weeks after use, and which have been required for truck drivers up until now,” California NORML’s Deputy Director Ellen Komp said. “This long-awaited move by DOT should help with the country’s supply-chain issues, while advancing employment rights for legal and responsible cannabis users without jeopardizing roadside safety.”

NORML has repeatedly argued that employers should not presume that the detection of either THC or its metabolites is evidence of impairment. That is because their presence is not predictive of diminished performance. Alternatively, NORML has called for the expanded use of performance-based tests, like DRUID or Predictive Safety’s AlertMeter.

In recent months, lawmakers in several states – including California and New York – have amended their employment laws so that most state employers may no longer terminate workers solely on the basis on a positive drug test for the presence of THC metabolites.

The full text of the Department’s forthcoming regulations appears in the Federal Register. Additional information on oral fluid testing is available from California NORML.