What Is Reasonable Suspicion Testing?
Reasonable suspicion testing — sometimes called "for cause" testing — is drug or alcohol testing triggered by a supervisor's direct, documented observation of specific signs of impairment at work. It is one of the most powerful tools in a drug-free workplace program, and one of the most legally sensitive.
Done correctly, it protects your company and gets an impaired employee off the floor before something goes wrong. Done incorrectly, it exposes you to discrimination claims, wrongful termination suits, and in DOT programs, regulatory violations.
The Two Key Requirements
For a reasonable suspicion test to be defensible, two things must be true:
- The supervisor must be trained. For DOT employers, this means 60 minutes of drug training and 60 minutes of alcohol training. For non-DOT employers, training is strongly recommended and some states or insurance policies require it.
- The observation must be documented in writing, in real time. Vague impressions don't cut it. You need specific, observable, articulable facts.
What Signs Justify Reasonable Suspicion?
Observable signs that may support a reasonable suspicion determination include:
- Slurred speech or incoherent communication
- Glassy, red, or dilated eyes
- Smell of alcohol or marijuana
- Unsteady gait, poor coordination, or stumbling
- Erratic behavior or mood swings inconsistent with normal baseline
- Extreme drowsiness or inability to stay awake during a shift
- Admission of drug or alcohol use
- Unusual or irrational behavior beyond the employee's normal range
What does NOT count: Rumors from other employees, anonymous tips, poor performance alone, or a supervisor's general feeling that something is "off." Reasonable suspicion must be based on direct, first-hand observation by a trained supervisor.
Step-by-Step: What to Do When You Suspect Impairment
1. Do not confront the employee about drug or alcohol use. That is not your role in this moment. Simply document what you observe.
2. Write it down immediately. Note the time, location, specific behaviors observed, and any other relevant details. Use exact language — not "seemed drunk" but "smelled strongly of alcohol, had slurred speech, stumbled when walking to the break room."
3. If possible, have a second supervisor observe and document independently. Two sets of documented observations significantly strengthen your position.
4. Remove the employee from their duties. Do not allow them to continue working in a potentially impaired state. Do not allow them to drive themselves home.
5. Call On Point Drug Testing. Dial 619-241-4415. Tell us it's a reasonable suspicion situation. We'll come to you in San Diego County.
6. Do not delay the test. For alcohol especially, time is a factor — alcohol metabolizes. The longer you wait, the more diluted the evidence.
Documentation: What to Write Down and When
Supervisor documentation is the backbone of a defensible reasonable suspicion case. Before the employee is sent for testing, the supervisor should complete a written record — ideally on a pre-printed form kept in the safety manager's office — noting the date, time, and location of observations, a factual description of what was seen and heard (avoid interpretive language like "appeared drunk" — use "slurred speech," "unsteady gait," "odor of alcohol on breath"), the name of any witnesses, and whether a second supervisor concurrence was obtained.
This documentation serves two purposes: it protects the employer if the test is negative (you acted on good faith, articulable observations, not prejudice), and it strengthens the employer's position if the test is positive and the employee challenges the action. Courts and arbitrators look for contemporaneous written records — notes written immediately after the event carry far more weight than recollections written weeks later.
The Two-Supervisor Rule: Why It Matters
DOT regulations require that reasonable suspicion determinations for safety-sensitive employees be made by a trained supervisor. Industry best practice — even for non-DOT programs — is to require concurrence from a second trained supervisor before sending an employee for testing. This eliminates single-point-of-failure bias (one supervisor with a grudge), reduces the risk of a discrimination claim, and creates a stronger administrative record.
Both supervisors should be trained in reasonable suspicion recognition. California employers can fulfill this with a half-day supervisor training session. On Point can connect you with HR consultants and EAP providers who offer this training in San Diego. Call 619-241-4415 for a referral.
What If the Employee Denies Impairment?
Employees almost always deny impairment when confronted. This is expected and does not undermine the reasonable suspicion determination. The threshold for reasonable suspicion is the supervisor's observations — not the employee's self-report. If a supervisor has documented specific, articulable signs of impairment, the testing obligation stands regardless of the employee's denial.
Do not argue with the employee about whether they are impaired. State clearly and calmly that based on your observations, you are required to send them for a drug and alcohol test per company policy. Offer them a ride or have them wait in a safe location until the collector arrives — do not let them drive themselves if impairment is suspected.
After the Test: Keeping the Employee Safe Until Results Return
A rapid screen preliminary result comes back within minutes. If the preliminary result is non-negative, the specimen goes to a lab for GC-MS confirmation, which typically takes 24–72 hours. During this window, the employee should be removed from safety-sensitive duties — with pay in most cases — pending the confirmed result. A preliminary non-negative is not a confirmed positive; do not treat it as one in communications with the employee.
If the confirmed result comes back negative, the employee should be returned to duty without negative employment action. If it comes back positive, follow your written policy. For DOT employees, the employee must be referred to a Substance Abuse Professional (SAP) before any return-to-duty pathway can begin.
Confidentiality
The reasonable suspicion determination and any test results must be kept strictly confidential. The employee's coworkers should not be told why the employee was removed from duty. Violations of this confidentiality can create additional legal exposure for your company.