A pre-employment drug test must be completed — and a verified negative result received — before a safety-sensitive employee can begin performing safety-sensitive functions for the first time. This applies to new hires, rehires, and employees transferring into a safety-sensitive role.
Testing TypeDrug only (no pre-employment alcohol test required under Part 40)
TimingMust have negative result before first safety-sensitive duty
Who DecidesEmployer — required by regulation before safety-sensitive work begins
Key RuleCannot begin duty until negative result is confirmed by MRO
Unannounced testing conducted on a scientifically random basis throughout the year. Every safety-sensitive employee in the random pool must have an equal chance of being selected at any time, regardless of prior test history. When selected, the employee must proceed immediately to the collection site.
FMCSA Rate (Drugs)50% of average number of safety-sensitive employees annually
FMCSA Rate (Alcohol)10% of average number of safety-sensitive employees annually
Selection MethodMust use a scientifically valid random selection method
Employee ObligationMust go immediately — cannot delay, reschedule, or be substituted
Owner-operators cannot be in their own random pool — they must join a consortium managed by a C/TPA to satisfy the random testing requirement.
Required after certain accidents involving safety-sensitive employees. The rules for what triggers a post-accident test and how quickly it must occur vary by DOT agency. FMCSA rules are the most commonly applicable.
FMCSA Post-Accident Triggers:
- Fatal accident: Always test — no exceptions
- Injury requiring off-site medical treatment: Test if employee receives a citation
- Disabling vehicle damage ($1,800+): Test if employee receives a citation
Alcohol WindowTest within 2 hours. If not possible, document why. Stop attempting after 8 hours.
Drug WindowTest within 32 hours. If not possible, document why and stop attempting.
A supervisor-initiated test based on specific, documented observations of an employee's appearance, behavior, speech, or body odor that are consistent with drug or alcohol use. The supervisor making the determination must be trained.
Who Can ReferOnly a supervisor who has completed the required 60+60 minute training
Alcohol WindowWithin 2 hours of determination; document if not done within 2 hrs; stop after 8
Drug WindowWithin 32 hours of determination
DocumentationSupervisor must document observations in writing before or shortly after referral
Required before a safety-sensitive employee can return to duty after violating DOT drug or alcohol regulations. The employee must first complete the SAP evaluation and prescribed treatment or education program. The return-to-duty test must always be conducted under direct observation.
PrerequisiteSAP evaluation and completion of treatment/education must occur first
Collection MethodDirectly observed — always, no exceptions
Result RequiredVerified negative before employee may return to safety-sensitive duty
Who AuthorizesSAP determines when the employee is ready; employer receives SAP report
After returning to duty, the employee enters a mandatory follow-up testing period. All follow-up tests are unannounced and conducted under direct observation. The schedule is determined by the SAP.
Minimum RequirementAt least 6 unannounced tests in the first 12 months after returning to duty
Maximum DurationUp to 60 months total follow-up testing period, as directed by SAP
Collection MethodAll follow-up tests are directly observed — no exceptions
Who SchedulesEmployer or C/TPA, based on SAP's prescribed schedule