DOT Proposes Significant Amendments to Drug & Alcohol Testing, Adding Fentanyl and Norfentanyl

The US Department of Transportation (DOT) recently proposed significant amendments to its drug and alcohol testing regulations that include adding fentanyl and its metabolite, norfentanyl, to the drug testing panels. The proposed amendments will impact applicants seeking positions as well as employees working in roles that perform safety-sensitive tasks, as that term is defined by the DOT’s regulations. This includes employees in various sectors such as aviation, trucking, rail, mass transit, pipelines, and other transportation industries regulated by DOT that are required to undergo drug and alcohol testing to ensure the safety and reliability of transportation services.

With the proposed amendments to 49 CFR Part 40 (titled “Procedures for Transportation Workplace Drug and Alcohol Testing Programs: Addition of Fentanyl to the Department of Transportation’s Drug-Testing Panel; Harmonization With Certain Items in the HHS Mandatory Guidelines for Urine and Oral Fluid; and Technical Amendments), the DOT aims to align its regulations with the US Department of Health and Human Services (HHS) Mandatory Guidelines for Federal Workplace Drug Testing Programs.

BACKGROUND

The DOT first published its drug testing procedures regulation, 49 CFR Part 40, on November 21, 1988 as an interim final rule. The rule was based on the Department of Health and Human Services’ (HHS) guidelines for federal agency employee drug testing with some changes to fit the transportation workplace. The DOT published a final rule a year later that included, among other things, a provision for a five-panel drug test for cocaine, marijuana, phencyclidine, amphetamines, and opiates.

Further, under the Omnibus Transportation Employee Testing Act (OTETA) of 1991, codified at 49 USC §§ 45102 and 45104 (aviation industry testing), 49 USC § 20140 (rail), 49 USC § 31306 (motor carriers), and 49 USC § 5331 (transit), the DOT was required to implement alcohol testing programs in various transportation industries. In response to OTETA, DOT added alcohol testing procedures to Part 40 in a final rule published on February 15, 1994.

The drug and alcohol testing program is designed to ensure that employees in safety-sensitive roles uphold their duty to maintain a safe work environment. As the DOT emphasizes, “[a]s an employee performing safety-sensitive functions in the transportation industry, you are responsible for providing a safe work environment for your co-workers and the traveling public. Creating a safe work environment not only means following established work rules but also following the DOT’s rules on drug use and alcohol misuse.”

Safety-sensitive duties subject to DOT drug and alcohol testing include: operating commercial motor vehicles requiring a CDL for motor carriers; serving as flight crew, flight attendants, flight instructors, air traffic controllers (at certain facilities), aircraft dispatchers, maintenance and preventative maintenance personnel, ground security coordinators, and aviation screeners for aviation; performing duties for railroads covered by Hours of Service laws—such as locomotive engineers, trainmen, conductors, switchmen, locomotive hostlers/helpers, utility employees, signalmen, operators, and train dispatchers; operating revenue service vehicles, CDL-holding operators of non-revenue service vehicles, vehicle controllers, revenue service vehicle mechanics, and armed security personnel for public transportation; performing operations, maintenance, or emergency response on regulated pipelines or LNG facilities for pipelines; and serving as crewmembers operating commercial vessels for maritime employers.

PROPOSED CHANGES

In its recently proposed rule, the DOT proposes the following amendment to Part 40 by:

1. Adding fentanyl and norfentanyl and their respective cutoffs for initial and confirmatory testing (as paralleled by the HHS urine and oral fluid drug testing panels published in the Federal Register on January 16, 2025 (90 FR 4662)) to the DOT drug testing panels (fentanyl would be added to both the urine and oral fluid testing panels, and norfentanyl to the urine testing panel);
2. Adjusting the laboratory confirmatory test cutoff for morphine in urine drug testing from 2,000 ng/mL to 4,000 ng/ml, which, per the DOT, should result in cost savings because more test results would now be reviewed by a Medical Review Officer (MRO) with no clinical exam;
3. Removing the requirement that an MRO determine clinical evidence of illegal opioid use to support a positive codeine or morphine result in urine and oral fluid drug testing;
4. Adding and defining the term “biomarker” and revising the definitions of “adulterated specimen,” “cutoff,” “initial specimen validity test,” “negative result,” “positive result,” and “substituted specimen” for clarity and consistency with HHS guidelines;
5. Authorizing laboratories to conduct biomarker testing once HHS approves laboratory biomarker testing;
6. Amending the analyte nomenclature for marijuana in both drug testing panels from THCA to Δ9THCC (urine) and Δ9THC (oral); and
7. Revising the footnotes in both drug testing panels to include more specific and updated criteria for alternate technology initial drug tests.

COMMENT PERIOD AND EMPLOYER GUIDANCE

Stakeholders are encouraged to submit comments on the proposed rule by October 17, 2025. Employers whose employees are subject to DOT regulations should closely monitor developments related to this rule and prepare for potential changes in their drug and alcohol testing protocols to ensure compliance with the updated regulations once finalized.