DOT Return to Duty Glossary

Short Answer

The DOT Return to Duty process uses precise terminology defined in 49 CFR § 40.3. Understanding these terms is the fastest way to understand the process itself, since many disputes and delays trace back to a misunderstanding of a single defined word. The glossary below lists the terms most relevant to the Return to Duty process, alphabetized for quick reference.

Glossary of Terms

Adulterated Specimen: A specimen that has been altered, as shown by the presence of a substance that is not normally found in human urine or by an abnormal concentration of a substance that is normally present.
Alcohol Concentration: The amount of alcohol in a person's breath, expressed as grams of alcohol per 210 liters of breath.
BAT (Breath Alcohol Technician): A person who instructs and assists employees during alcohol testing and operates an Evidential Breath Testing device (EBT).
Cancelled Test: A drug or alcohol test that has a problem identified under Part 40 that was not or could not be corrected. A cancelled test is neither positive nor negative.
Chain of Custody: The documented history of a specimen's handling, from collection through testing to final disposition, recorded on the Federal Custody and Control Form (CCF).
Clearinghouse: The Commercial Driver's License Drug and Alcohol Clearinghouse, a database administered by FMCSA that contains records of CDL holders' violations of drug and alcohol testing requirements and their Return to Duty status.
Collector: The person who instructs and assists an employee at a collection site and who completes the Federal Custody and Control Form.
Consortium/Third-Party Administrator (C/TPA): A service agent that provides or coordinates drug and alcohol testing services on behalf of an employer. A C/TPA performs administrative functions but is not itself an employer under Part 40.
Designated Employer Representative (DER): An employee authorized by the employer to remove employees from safety-sensitive duty and to make required decisions in the testing and evaluation process. A service agent cannot act as a DER.
Dilute Specimen: A urine specimen with creatinine and specific gravity values that are lower than expected for normal human urine.
Drugs Tested Under Part 40: The five drug classes tested under the DOT program: marijuana, cocaine, amphetamines, phencyclidine (PCP), and opioids.
Employer: The entity subject to DOT drug and alcohol testing regulations. Service agents, including C/TPAs, laboratories, and SAPs, are not employers under Part 40.
Medical Review Officer (MRO): A licensed physician responsible for receiving and reviewing laboratory drug test results and evaluating any medical explanations offered for certain results.
Negative Result: A laboratory finding that a valid specimen shows no drug or drug metabolite present, or a concentration below the applicable cutoff.
Non-Negative Specimen: A specimen reported by the laboratory as adulterated, substituted, positive, and/or invalid.
Office of Drug and Alcohol Policy and Compliance (ODAPC): The office within the Office of the Secretary of the Department of Transportation that coordinates DOT drug and alcohol testing program policy across the modal agencies.
Primary Specimen and Split Specimen: The primary specimen (the "A" bottle) is tested first. The split specimen (the "B" bottle) is retained and, if the primary is verified positive, adulterated, or substituted, may be sent for independent testing at the employee's request.
Screening Test Technician (STT): A person who instructs and assists employees during alcohol testing and operates an alcohol screening device (ASD).
Service Agent: Any person or entity other than an employer that provides drug or alcohol testing services, including collectors, BATs, STTs, laboratories, MROs, SAPs, and C/TPAs.
Substance Abuse Professional (SAP): A qualified professional who evaluates an employee who has violated a DOT drug or alcohol regulation and who makes recommendations concerning education, treatment, follow-up testing, and aftercare.
Substituted Specimen: A specimen with creatinine and specific gravity values so diminished or divergent that the result is not consistent with normal human urine.
Verified Test: A laboratory result that has gone through Medical Review Officer review and received a final determination.

Applicable Regulations

49 CFR § 40.3, Definitions

Professional Observation

In my experience, many disagreements between an employee and an employer during the Return to Duty process come down to a term being used loosely rather than in its regulatory sense. A "cancelled" test is not the same as a "negative" test, and a "dilute" specimen is not the same as a "substituted" specimen. Learning the exact definitions early helps everyone involved communicate accurately.

Primary Authorities

49 CFR § 40.3, Definitions

Have Questions About Terminology in Your Case?

If a term in your Return to Duty paperwork is unclear, a DOT qualified Substance Abuse Professional can walk you through exactly what it means for your situation.

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