DOT Regulators Take Action to Detect Employee Fentanyl Use

Employees who are subject to U.S. Department of Transportation (DOT) drug testing regulations will be tested for fentanyl along with other drugs on DOT panels under a proposed rule that was published in the Federal Register on Sept on Sept. 2, 2025. A related public comment period will end on Oct. 17, 2025.  2, 2025. A rtheelated public comment period for the proposed change in DOT testing for fentanyl will end on Oct. 17, 2025.

The proposal applies to commercial motor vehicle drivers, other highway, rail, air, pipeline, transit, and maritime workers, and service agents who are subject to DOT drug testing regulations (49 CFR part 40). Test panels would include fentanyl, a synthetic opioid, and norfentanyl, a fentanyl metabolite.

The addition of fentanyl to DOT drug panels is required to align with U.S. Department of Health and Human Services (HHS) Mandatory Guidelines for Federal Workplace Drug Testing Programs. The DOT also proposes to amend certain provisions of part 40 to harmonize with HHS guidelines on the use of urine and oral fluid testing.

Why Fentanyl Use Demands Employers’ Attention

Fentanyl is a potent synthetic opioid with high potential for addiction and overdose. In some cases, illicit manufactured fentanyl is used as a substitute for prescription opioid medications. In the U.S., 7 in 10 overdose deaths are estimated to involve illegally manufactured fentanyls (IMFs), according to the Centers for Disease Control and Prevention. The HHS Federal Drug-Free Workplace Program added fentanyl to its authorized drug testing panel effective July 7, 2025.

In the workplace, fentanyl use is associated with serious health, safety, and legal liability concerns for users, co-workers, and employers. Potential side effects include drowsiness, confusion, and delayed reaction times, increasing risk for accidents and injuries.

Newly released findings from the Quest Diagnostics 2025 Drug Testing Index™ found that other drugs are used in combination with fentanyl about 60% of the time, increasing risk for impairment.

Quest publishes its annual index findings to provide insights on the use of illicit, legal, and prescription drugs in the U.S. workforce.

The 2025 index shows changing patterns in drug use by the nation’s workforce. Notably, in 2024, the positivity rate for fentanyl was more than seven times higher in random tests taken by current employees than it was for prospective employees subject to pre-employment drug screening. This suggests that a significant percentage of workers begin or return to fentanyl use after they have been hired. Far less variation was seen in random and pre-employment positivity rates in among other opiates and for marijuana, Quest reported.

The new Quest data indicates a worrying increase in fentanyl positivity in random drug tests as well as fentanyl drug-combining among the nation’s workforce in day-to-day work environments. It also raises concern that employees are turning to a dangerous drug like fentanyl after they’ve passed a pre-employment drug screen, putting the overall wellness of the workforce at risk.
– Suhash Harwani, Ph.D., senior director of science for Workforce Health Solutions at Quest Diagnostics.

Other Noteworthy Findings from the Quest Index

Quests’ annual analysis of more than 8 million urine drug tests shows an overall decline in positivity rates – from 4.6% in 2023 to 4.4% in 2024 – in the general U.S. workforce population. Among the general U.S. workforce, Quest found:

• Marijuana continues to be the most frequently detected substance, holding steady at 4.5% in the general U.S. workforce year over year.
• Post-accident positivity for marijuana was 7.3% in 2024. The positivity rate for marijuana in random testing was 42% lower than the positivity rate in pre-employment testing.
• Substances detected in 60% of specimens that tested positive for fentanyl included marijuana (22%) and amphetamines (16%).
• About 1 in 3 employees tested for cause were positive for drug use, an indicator of impairment effects.

More About the Proposed DOT Rule Change

In addition to adding fentanyl to drug panels, the DOT proposes to remove a requirement for medical review officers (MROs) to look for clinical evidence of illegal opioid use when a laboratory confirms a positive codeine/morphine result that is less than 15,000 ng/mL. The cutoff adjustment is expected to simplify verification of positive results. Other provisions include:

• Adding biomarkers for urine and oral fluid testing to detect substituted specimens
• Modifying analyte nomenclature for marijuana (urine and oral-fluid testing)
• Adding a 30-day requirement for specimen collectors, screening test technicians, and breath alcohol technicians to complete required training and mock collections

Solutions to Help Prevent Drug-related Incidents

Studies show that positivity rates tend to be lower among safety-sensitive workers who are subject to federal drug testing mandates than they are for employees who are not tested. Proactive safety strategies that include consistent enforcement of a comprehensive drug screening program help discourage drug use in the general employee population, regardless of whether a workplace is subject to drug testing regulations.

WorkCare has a team of experts to help your company develop effective substance testing policies and procedures in response to workforce use trends and compliance mandates. We assist with specimen collections and testing for pre-placement, random, for-cause/reasonable suspicion, and post-accident purposes, and we employ MROs who are trained to analyze and follow up on results.

Workplace drug and alcohol testing is an essential occupational health and safety management tool.

Contact us to learn how we can help with drug and alcohol screening.