Drug Testing Glossary – Key Terms Defined

A B C D E F M O P R S T

A

Aliquot: A measured portion of a specimen used for testing. In a split specimen collection, the primary specimen (Bottle A) is tested first; the split specimen (Bottle B) is held in reserve and only tested if the donor requests a retest.
ASD — Alcohol Screening Device: A DOT-approved device used to conduct a breath alcohol screening test. An ASD can only be used for screening — not for confirmation tests. If a screening result is 0.020 or above, a confirmation test on an approved EBT device is required.
ATF — Alcohol Testing Form: The federal form used to document a DOT breath alcohol test. The ATF captures donor identity, reason for test, screening result, confirmation result (if applicable), and signatures from both the BAT and the donor.

B

BAT — Breath Alcohol Technician: A trained individual qualified to conduct DOT breath alcohol screening and confirmation tests using an approved ASD or EBT device. BATs must complete specific training and pass a proficiency demonstration before conducting tests.
Bottle A / Bottle B: The two sealed specimen containers in a DOT split specimen collection. Bottle A (primary) receives at least 30 mL and is sent to the lab for testing. Bottle B (split) receives the remainder and is held in reserve. If the donor requests a retest, Bottle B is sent to a second HHS-certified lab.

C

CCF — Chain of Custody Form: The federal five-part form used to document a DOT urine drug collection. The CCF tracks the specimen from the moment of collection through laboratory testing and MRO review. Each copy is distributed to a specific party: employer, MRO, lab, collector, and donor.
CLIA — Clinical Laboratory Improvement Amendments: Federal regulations that govern all laboratory testing on human specimens. Facilities that read and report rapid drug screen results onsite must obtain a CLIA certificate. DOT urine collectors who only collect and ship specimens to a certified lab are generally not subject to CLIA.
Collector: A trained individual qualified to collect urine specimens for DOT drug testing. Collectors must complete required training and pass a proficiency demonstration per 49 CFR Part 40.33 before conducting collections.
Correctable Flaw: An error in the collection or documentation process that does not automatically cancel the test but must be corrected with a written statement from the collector, donor, or employer. Examples include omitting a printed name on the CCF or failing to mark the reason for test.

D

DER — Designated Employer Representative: The person at a company authorized to receive drug and alcohol test results and take immediate action if needed (e.g., removing a safety-sensitive employee from duty). Collectors should contact the DER when a refusal, shy bladder, or other problem scenario occurs.
Direct Observation Collection: A collection procedure where the collector (or same-gender observer) watches the donor urinate directly into the collection container. Required in specific situations including: out-of-range specimen temperature, return-to-duty tests, follow-up tests, and when the lab reports a specimen as substituted or invalid.
DOT 5-Panel: The five drug classes tested on all DOT urine drug tests: marijuana (THC), cocaine, opioids, amphetamines/methamphetamines, and phencyclidine (PCP). No additional substances may be added to a DOT test panel.

E

EBT — Evidential Breath Testing Device: A DOT-approved breath testing instrument capable of producing a printed result record. Required for all DOT confirmation breath alcohol tests. EBT devices must appear on the NHTSA Conforming Products List and be regularly calibrated to remain approved for use.

F

Fatal Flaw: A collection error serious enough to automatically cancel the test. Fatal flaws cannot be corrected after the fact — a new collection must be performed. Examples include failing to verify donor ID, not checking specimen temperature within 4 minutes, and applying specimen seals outside the donor's presence.
FMCSA — Federal Motor Carrier Safety Administration: The DOT agency that regulates commercial truck and bus drivers. FMCSA requires DOT drug and alcohol testing for CDL holders operating commercial motor vehicles in interstate commerce.
Follow-Up Testing: Unannounced testing required after a safety-sensitive employee completes the return-to-duty process following a positive or refused DOT drug/alcohol test. Follow-up tests are directed by the SAP and must include at least 6 unannounced tests in the first 12 months.

M

MRO — Medical Review Officer: A licensed physician responsible for receiving, reviewing, and interpreting all DOT drug test results reported by the laboratory. The MRO contacts donors directly when a non-negative result is reported, gives donors the opportunity to provide a legitimate medical explanation, and makes the final determination on the test result before reporting to the employer.

O

Observed Collection: See Direct Observation Collection. The terms are used interchangeably. In an observed collection, the collector or a trained same-gender observer directly watches the urine specimen leave the donor's body and enter the collection container.

P

Part 40 (49 CFR Part 40): The federal regulation that establishes all procedures for DOT workplace drug and alcohol testing programs. Part 40 covers collection procedures, laboratory testing, MRO review, SAP evaluation, and return-to-duty requirements. It applies across all DOT-regulated industries.
PCC — Point-of-Care Collection (or Point-of-Care Testing): Testing performed and read at the collection site rather than sent to a laboratory. Instant urine drug screen cups and rapid test strips are examples. Point-of-care testing is not permitted for DOT-regulated tests, which must be analyzed by an HHS-certified laboratory.

R

Random Testing: Unannounced drug and alcohol testing conducted throughout the year on a scientifically random basis. Safety-sensitive employees must be notified and proceed immediately to the collection site. Employers must meet DOT minimum random testing rates, which vary by agency (e.g., FMCSA requires 50% for drugs, 10% for alcohol annually).
Refusal to Test: Any behavior by a donor that prevents a test from being completed — including failing to appear, leaving the site, refusing to sign the CCF, or admitting to tampering. Under DOT regulations, a refusal to test is treated identically to a verified positive result.

S

SAMHSA — Substance Abuse and Mental Health Services Administration: The federal agency that certifies laboratories to conduct DOT urine drug testing. All DOT urine specimens must be sent to an HHS/SAMHSA-certified laboratory. SAMHSA-certified labs follow strict chain of custody, testing, and reporting standards.
SAP — Substance Abuse Professional: A licensed clinical professional who evaluates employees who have violated DOT drug and alcohol regulations. The SAP recommends a treatment or education program, determines when the employee is ready to return to safety-sensitive duty, and prescribes a follow-up testing schedule.
Shy Bladder: A situation where a donor is unable to provide a sufficient urine specimen (minimum 45 mL) at the time of collection. The collector must follow a specific shy bladder protocol — offering water, keeping the donor on-site, and allowing up to 3 hours total before cancelling the test and notifying the DER.
Split Specimen: All DOT urine collections use a split specimen kit. The primary specimen (Bottle A) is sent for testing; the split specimen (Bottle B) is sealed and held. If the donor's Bottle A result is positive, adulterated, or substituted, the donor may request that Bottle B be sent to a second HHS-certified lab for independent testing.
STT — Screening Test Technician: A trained individual qualified to conduct DOT breath alcohol screening tests using an approved ASD. Unlike a BAT, an STT cannot conduct confirmation tests. If a screening result is 0.020 or above, a BAT must administer the confirmation test within 30 minutes.

T

TPA — Third Party Administrator: A company or individual that provides drug and alcohol testing program management services to employers — including scheduling collections, managing random pools, coordinating MRO services, and maintaining compliance records. TPAs act on behalf of employers but cannot make employment decisions. Under DOT regulations, employers remain ultimately responsible for their testing program even when using a TPA.

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