Reasonable Suspicion Alcohol Testing: Documentation That Stands Up

A reasonable suspicion alcohol test is the one DOT test category that lives or dies on paperwork written by a non-medical person under time pressure. There's no random selection list, no scheduled date on a calendar — just a trained supervisor's observations, written down before the test happens, defending a decision that will get challenged if the result is positive or the employee is terminated.

What counts as reasonable suspicion under 49 CFR Part 40?

Reasonable suspicion under 49 CFR Part 40 requires specific, contemporaneous, articulable observations of the employee's appearance, behavior, speech, or body odors consistent with alcohol use — made by a supervisor trained to recognize the signs. It is not a hunch, a rumor from a coworker, or a pattern of past problems. The supervisor who makes the call must personally observe the employee, and for alcohol specifically, the observations must be made at or right before the time the decision to test is made — unlike drug testing, where a broader pattern can support the referral. The regulation exists precisely so that testing decisions can't be retrofitted after the fact to justify a result someone didn't like.

Who is allowed to make the call?

Only a supervisor or company official who has completed the required reasonable suspicion training can initiate the test — one hour on alcohol indicators, one hour on drug indicators, both required under §382.603 for DOT-regulated employers. A coworker's tip, a customer complaint, or a manager without the training certificate can trigger a conversation and a call to a trained supervisor, but they cannot order the test themselves. If your program can't produce a signed training record for the supervisor who made the call, the test is vulnerable regardless of what the breath result showed.

What has to be written down, and when?

Element	Requirement	Common failure
Specific observations	Concrete, sensory details — slurred speech, odor of alcohol, unsteady gait, visible confusion	Vague language like "acting strange" or "seemed off"
Timing	Documented before the test result is known, ideally before the test itself	Written retroactively after a positive result, undermining credibility
Two-observation rule (some employers)	Many programs require a second trained supervisor to concur when feasible	Single observer with no corroboration on a contested case
Testing window	Alcohol test within 2 hours of the determination; document if it exceeds 2 hours, must cease attempts after 8	No record of why testing was delayed
Signature and date	Supervisor signs and dates the observation form at the time of the decision	Undated notes added to the file later

What does a defensible observation actually look like on paper?

The difference between a form that holds up and one that gets thrown out is specificity. "Employee appeared intoxicated" is a conclusion, not an observation, and it invites a challenge that the supervisor was guessing. A defensible entry describes exactly what was seen and heard: "At 9:40 AM, employee's speech was slurred on multiple words during a normal work conversation, eye contact was difficult to maintain, and a strong odor of alcohol was present on his breath from approximately three feet away." That level of detail lets a third party — an arbitrator, an MRO, a court — evaluate the decision independently of the test result. Write the observation before you know how the breath test comes back, note the exact time, and have the supervisor sign it themselves rather than have HR summarize it later.

What happens after the observation is documented?

Once a trained supervisor documents reasonable suspicion, the employee must be tested within 2 hours of the determination, with a hard requirement to stop trying after 8 hours if a Breath Alcohol Technician isn't available — and the employee must be removed from safety-sensitive duty immediately, before the test happens, based on the observation alone. If the test can't happen within 2 hours, the supervisor documents why. If it doesn't happen within 8 hours, testing stops entirely and the employer documents the reason no test occurred, since the removal from duty already addressed the immediate safety concern independent of the result.

How Foster handles reasonable suspicion documentation

When we run BAT technician and supervisor training for a client, we build the observation form into the training itself rather than handing it over as a separate document nobody has practiced with. Supervisors work through mock scenarios — slurred speech during a shift-change conversation, an odor reported by a coworker, unsteady movement near equipment — and write the observation in real time, then get feedback on whether the language would survive a challenge. We've seen too many programs where the training checks a compliance box but the actual observation form filled out six months later during a real incident is a single vague sentence. The forms we provide have prompts for time, specific behaviors, and signature fields built in, so a rushed supervisor still produces something defensible.

Frequently asked questions

Can a supervisor order a reasonable suspicion test based on something a coworker reported?

Not directly. A coworker's report can prompt the trained supervisor to personally observe the employee, but the supervisor must make their own direct observations before ordering the test — secondhand reports alone are not sufficient under Part 40.

Does the employee have to be tested immediately, or can it wait until end of shift?

Testing should happen as soon as possible and within 2 hours of the determination. The employee is removed from safety-sensitive duty immediately regardless of when the test itself can be arranged, and testing must stop after 8 hours if it hasn't occurred.

What if the reasonable suspicion test comes back negative?

A negative result doesn't retroactively invalidate a properly documented observation. Employers typically still address the underlying behavior through other channels, but the reasonable suspicion determination itself is judged on whether the observation met the standard at the time, not on the test outcome.

Do both drug and alcohol reasonable suspicion require the same training?

No — the training requirement is one hour on alcohol misuse symptoms and a separate one hour on controlled substance use symptoms, and both hours are required for a supervisor to make either type of determination.

How long should reasonable suspicion documentation be kept on file?

Records related to a reasonable suspicion alcohol test follow the same retention rules as other DOT alcohol testing records — most documentation for a violation is retained for 5 years. Employers should confirm current retention schedules rather than relying on memory, since requirements are set by regulation and can be updated.

Foster Special Instruments provides BAT technician and supervisor reasonable suspicion training, on-site alcohol testing, and instrument calibration services for DOT-regulated employers. Related reading: post-accident alcohol testing and the 8-hour clock. Need a program built out? Request a quote.