DOT 5-Panel Drug Test: Substances, Who Tests, and Refusals

The DOT 5-panel drug test is the federally mandated screening every safety-sensitive transportation worker takes, and it checks for five categories of controlled substances: marijuana, cocaine, amphetamines, phencyclidine, and opioids. The framework comes from the Omnibus Transportation Employee Testing Act of 1991, and the same protocol applies whether you drive a truck, fix aircraft, run a train, or operate a pipeline.1Federal Motor Carrier Safety Administration. Overview of Drug and Alcohol Rules for Employers The rules live in 49 CFR Part 40.

The Five Categories

The “5-panel” label understates what the test catches, because the opioid category alone covers several distinct drugs. The five categories under 49 CFR 40.85 are:

  • Marijuana. The lab looks for THC metabolites (Delta-9-tetrahydrocannabinol-9-carboxylic acid, or THCA).
  • Cocaine. The target is benzoylecgonine, the primary metabolite your body produces after cocaine use.
  • Amphetamines. This covers amphetamine, methamphetamine, MDMA, and MDA.
  • Phencyclidine (PCP).
  • Opioids. A single category that tests for codeine, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone, and 6-acetylmorphine (a heroin marker).

6-acetylmorphine is included specifically because it is a definitive indicator of heroin use; your body doesn’t produce it from anything else.2eCFR. 49 CFR 40.85 – What Drugs Does the DOT 5-Panel Test For

Cutoff Levels

Each substance has a threshold measured in nanograms per milliliter. A specimen below the cutoff is reported negative even when trace amounts are present. Testing runs in two stages: an initial immunoassay screen at a higher cutoff, and, for anything that hits that threshold, a confirmatory test at a lower cutoff using gas chromatography-mass spectrometry. Key urine thresholds:3eCFR. 49 CFR Part 40 – Procedures for Transportation Workplace Drug and Alcohol Testing Programs

  • Marijuana (THCA): 50 ng/mL initial, 15 ng/mL confirmatory
  • Cocaine (benzoylecgonine): 150 ng/mL initial, 100 ng/mL confirmatory
  • Codeine and morphine: 2,000 ng/mL for both
  • Hydrocodone and hydromorphone: 300 ng/mL initial, 100 ng/mL confirmatory
  • Oxycodone and oxymorphone: 100 ng/mL for both
  • 6-acetylmorphine: 10 ng/mL for both
  • PCP: 25 ng/mL for both
  • Amphetamine, methamphetamine, MDMA, and MDA: 500 ng/mL initial, 250 ng/mL confirmatory

The codeine and morphine thresholds are high because these substances can turn up from foods like poppy seeds. The lower thresholds for semi-synthetic opioids like hydrocodone and oxycodone reflect the fact that those drugs have no innocent dietary explanation.

Since June 2023, DOT-regulated employers can also use oral fluid (saliva) testing. Saliva cutoffs are much lower than urine cutoffs because concentrations in saliva are naturally smaller; the marijuana initial cutoff, for example, is 4 ng/mL in oral fluid versus 50 ng/mL in urine. Oral fluid collection is directly observed, which makes it harder to cheat and useful for post-accident and reasonable-suspicion tests.

Who Has to Test

The requirement reaches anyone performing a safety-sensitive function under six federal agencies. Each agency defines its own covered positions, but the 5-panel protocol and collection rules are identical:

Independent owner-operators are not exempt. If you hold a CDL and operate a commercial motor vehicle, you must belong to a consortium or third-party administrator that handles your random testing and Clearinghouse queries.10Federal Motor Carrier Safety Administration. Drug and Alcohol Clearinghouse Registration and Requirements for Owner-Operators

When Testing Happens

Testing occurs in six situations, each with its own trigger.

Pre-employment. Your employer must have a negative result in hand before you perform any safety-sensitive work.11Federal Motor Carrier Safety Administration. When Does Testing Occur and What Tests Are Required

Random. Employers select employees for unannounced testing throughout the year. For 2026, drug testing selection rates range from 25% (FAA, most FRA categories) to 50% (FMCSA, FTA, PHMSA, and FRA mechanical employees), with alcohol random testing at 10% across all agencies.12U.S. Department of Transportation. Random Testing Rates A 50% rate refers to the size of the selection pool, not a guarantee any individual will be picked; some workers get selected more than once in a year, others not at all.

Post-accident. After a crash involving a commercial motor vehicle on a public road, testing is required if someone died (regardless of citation), someone needed immediate off-scene medical treatment and the driver was cited, or a vehicle had to be towed and the driver was cited. Drug testing must occur within 32 hours. Alcohol testing must occur within 8 hours or the employer stops trying and documents why.13eCFR. 49 CFR 382.303 – Post-Accident Testing Leaving the scene for anything other than emergency medical care can be treated as a refusal.

Reasonable suspicion. A supervisor trained in the signs of drug and alcohol misuse (at least 60 minutes on each) can direct you to an immediate test based on specific personal observations, not rumor.14eCFR. 49 CFR 382.603 – Training for Supervisors

Return-to-duty and follow-up. Anyone who has violated a DOT drug or alcohol rule must pass a directly observed return-to-duty test before resuming safety-sensitive work, followed by at least six unannounced tests in the first 12 months, with the Substance Abuse Professional able to extend follow-up testing for up to 48 additional months.15Federal Motor Carrier Safety Administration. Follow-Up Testing (Under Direct Observation)

What Happens at the Collection Site

Bring a valid government-issued photo ID. The collector verifies who you are and starts the Federal Drug Testing Custody and Control Form, which follows the specimen from collection through lab result. Once check-in begins, you have to stay until you provide a sufficient sample. Leaving early can be recorded as a refusal, which counts the same as a positive result.16eCFR. 49 CFR 40.191 – What is a Refusal to Take a DOT Drug Test

For a urine collection, you need to provide at least 45 milliliters in a single void. The collector splits it into two bottles: at least 30 mL in Bottle A for primary testing, and at least 15 mL in Bottle B as a backup you can later request to have tested.17U.S. Department of Transportation. 49 CFR 40.193 Specimen temperature is checked within four minutes and must fall between 90°F and 100°F.18eCFR. 49 CFR 40.65 – What Does the Collector Check for When the Employee Presents a Specimen Tamper-evident seals go on both bottles in front of you, and you both sign the form confirming the labels are correct.

If You Can’t Produce Enough Urine

The collector discards the insufficient sample and starts a three-hour window in which you’re encouraged (not required) to drink up to 40 ounces of fluid. If you still can’t produce 45 mL, the collection ends and your employer’s Designated Employer Representative is notified. The Medical Review Officer then sends you to a physician within five days to determine whether a medical condition explains it. If the physician finds no medical explanation, the outcome is treated as a refusal.19eCFR. 49 CFR 40.193 – What Happens When an Employee Does Not Provide a Sufficient Amount of Specimen for a Drug Test Situational anxiety and undocumented dehydration don’t qualify.

Lab Analysis and the Medical Review Officer

Specimens go to a laboratory certified by the Department of Health and Human Services.20Federal Register. Current List of HHS-Certified Laboratories and Instrumented Initial Testing Facilities Anything that hits the initial cutoff moves to confirmatory testing at the lower threshold. Only a confirmed positive advances; an initial positive that doesn’t survive confirmation is reported as negative.

A confirmed positive doesn’t go straight to your employer. It reaches a Medical Review Officer first, a licensed physician trained specifically for the role. The MRO reviews the chain of custody and then contacts you for an interview. This is when you can present a legitimate medical explanation, usually a valid prescription for the substance detected. If the MRO is satisfied the medication was taken as prescribed, the result can be reported as negative.21eCFR. 49 CFR Part 40 Subpart G – Medical Review Officers and the Verification Process

Without a valid medical explanation, the MRO verifies the result as positive and reports it to your employer. From the time the MRO notifies you, you have 72 hours to request that your Bottle B split specimen be tested at a different certified lab. Your employer must pay for that test upfront; they may seek reimbursement later, but they cannot make you cover it before it happens.

CBD and State Marijuana Laws

State marijuana laws (medical or recreational) have no effect on DOT testing. The DOT has stated that it remains unacceptable for any safety-sensitive employee to use marijuana regardless of state law, and that the testing regulations will remain in effect even if marijuana is rescheduled at the federal level until that process is complete.22U.S. Department of Transportation. DOT’s Notice on Testing for Marijuana

CBD is a real risk. The DOT tests for THC, not CBD, but many CBD products contain more THC than their labels claim, and the FDA does not certify THC levels in these products. If a CBD product produces a positive marijuana result, the MRO will verify it as positive. Believing in good faith that a product contained no THC is not a legitimate medical explanation.23U.S. Department of Transportation. DOT CBD Notice

What Counts as a Refusal

A refusal carries the same consequences as a verified positive, and the definition in 49 CFR 40.191 is broader than most people expect. You’ve refused if you:

  • Don’t show up within a reasonable time after being directed to test (except for pre-employment).
  • Leave the collection site before the process is complete.
  • Fail to provide a specimen for any required test.
  • Refuse direct observation when the test requires it (return-to-duty and follow-up tests are always directly observed).
  • Fail the shy bladder evaluation without a medical explanation.
  • Refuse to empty your pockets, behave disruptively, or fail to wash your hands when directed.
  • Skip the medical evaluation the MRO directs you to.
  • Bring an adulterant or substitution device to the collection.

The collector isn’t required to warn you that a specific action will be treated as a refusal. If you leave and the employer determines your departure wasn’t justified, the refusal goes on your record whether or not anyone warned you.

What a Positive Result Costs You

Your employer must immediately remove you from all safety-sensitive duties upon receiving a verified positive; they don’t wait for the written report or a split-specimen retest.24eCFR. 49 CFR 40.23 – What Actions Do Employers Take After Receiving Verified Test Results You can’t return to safety-sensitive work until you complete every step of the return-to-duty process.

That process begins with a Substance Abuse Professional, who conducts an initial face-to-face evaluation, recommends education or treatment, and then re-evaluates you afterward.25U.S. Department of Transportation. 49 CFR Part 40 Section 40.281 – Who Is Qualified to Act as a SAP Once the SAP confirms you’ve complied, you take a directly observed return-to-duty test and need a negative result before doing any safety-sensitive work. The SAP then sets a follow-up plan with at least six unannounced tests in the first 12 months, extendable up to 60 total months.26Federal Motor Carrier Safety Administration. The Return-to-Duty Process and the Clearinghouse Completing the process makes you eligible to return; it does not obligate your employer to rehire you.

The FMCSA Clearinghouse (CDL Drivers)

Since January 2020, FMCSA has maintained a national database, the Drug and Alcohol Clearinghouse, that tracks CDL driver violations. Positive results, refusals, and “actual knowledge” violations (such as a DUI citation in a commercial vehicle) are reported to it, along with return-to-duty completion and follow-up testing records.27Federal Motor Carrier Safety Administration. Clearinghouse FAQs – Violations Employers must query the Clearinghouse before hiring any CDL driver and at least once every 12 months for every current CDL driver.28Federal Motor Carrier Safety Administration. What Is the Annual Requirement for Employee Queries and How Is It Tracked A violation stays in the Clearinghouse for five years from the date it was recorded, or until you complete the full return-to-duty process including all follow-up testing, whichever takes longer. Quitting and getting hired across town is no longer a way around a positive test.