What is a DOT drug test?
A DOT drug test is a urine drug screening regulated by the U.S. Department of Transportation under 49 CFR Part 40. It applies to "safety-sensitive" employees of DOT-regulated transportation industries, including:
- FMCSA — Federal Motor Carrier Safety Administration (commercial truck drivers, CDL holders)
- FAA — Federal Aviation Administration (pilots, mechanics, flight crew)
- FRA — Federal Railroad Administration
- FTA — Federal Transit Administration (transit operators)
- PHMSA — Pipeline and Hazardous Materials Safety Administration
- USCG — U.S. Coast Guard (commercial vessel crew)
What does a DOT drug test screen for?
DOT testing uses the federally-mandated SAMHSA-5 panel with expanded opiate coverage:
- Marijuana (THC)
- Cocaine
- Opiates — including codeine, morphine, heroin metabolites, plus oxycodone, oxymorphone, hydrocodone, hydromorphone (since 2018)
- Amphetamines (including methamphetamine and MDMA)
- Phencyclidine (PCP)
Breath alcohol testing is a separate requirement, conducted with FDA-cleared Evidential Breath Testing (EBT) devices. Browse breath alcohol testing supplies.
When is DOT testing required?
- Pre-employment — before performing safety-sensitive duties
- Random — 50% of safety-sensitive employees annually (FMCSA: 50% drug, 10% alcohol)
- Post-accident — following qualifying incidents
- Reasonable suspicion — based on documented supervisor observations
- Return-to-duty — after a violation, before resuming safety-sensitive functions
- Follow-up — ongoing monitoring after violations (minimum 6 tests in 12 months)
DOT-compliant supplies from American Screening Corp
- DOT testing supplies for transportation companies
- 5 panel SAMHSA cups meeting Part 40 panel requirements
- Forensic-grade collection cups with chain-of-custody temperature strips
- Evidential Breath Testing (EBT) devices
- DOT Drug Test Software — ASC's program compliance management platform
DOT testing process — the legal flow
- Collection — by a DOT-trained collector using a chain-of-custody-compliant specimen cup
- Laboratory testing — specimen sent to an HHS-certified laboratory for GC-MS or LC-MS/MS analysis
- Medical Review Officer (MRO) verification — a licensed physician reviews any positive lab result and interviews the donor to rule out legitimate medical explanations
- Verified result — MRO reports a verified negative, positive, or refusal-to-test to the employer
- Employer action — based on the verified result and the company's written policy
Bypassing the MRO step or acting on a screening result alone is a violation of 49 CFR Part 40 and a frequent source of wrongful-termination litigation.
DOT drug test FAQ
How long does a DOT drug test stay on record?
DOT employers are required to maintain testing records for a minimum of 5 years. Positive results, refusals, and SAP referrals are reported to the FMCSA Drug & Alcohol Clearinghouse (for commercial driver license holders) and remain queryable for at least 5 years.
Can a CDL driver use medical marijuana?
No. Under 49 CFR Part 40, marijuana use — including state-legal medical marijuana — remains a federal disqualifier for safety-sensitive DOT positions. State medical marijuana cards do not provide a DOT exemption.
What happens after a DOT positive?
The employee is immediately removed from safety-sensitive duties. They must complete a Substance Abuse Professional (SAP) evaluation, follow the prescribed treatment plan, pass a return-to-duty test, and complete a minimum 6 follow-up tests in 12 months before returning to safety-sensitive work.
Setting up a DOT program? Browse DOT supplies, learn about ASC's DOT compliance software, or call 318-798-3306 for program guidance.
