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Alcohol Testing


In 1991, the United States Congress passed the Omnibus Transportation Employee Testing Act. This established drug and alcohol testing guidelines for companies and agencies that the Department of Transportation (DOT) governs. It is important for all motor carriers to follow DOT and Federal Motor Carrier Safety Administration (FMCSA) guidelines in order to stay compliant and to keep employees and others on the road safe.

Here is what you should know about DOT-required testing:

What is a Safety-Sensitive Employee?

The DOT and FMCSA require certain types of drug and alcohol testing for safety-sensitive employees. These are individuals who have jobs that can impact their own safety as well as the safety of the larger public. For motor carriers, this includes anyone who operates a commercial vehicle. An employee is designated as safety-sensitive based on the tasks they perform rather than based on their job title.

Prohibited Conduct for Alcohol

FMCSA regulations outline alcohol violations for safety-sensitive employees. Subpart B of Part 383 of federal transportation regulations lists types of prohibited conduct.

These include:

Having an Alcohol Concentration Over 0.02

Safety-sensitive employees may not report for duty if they have a blood alcohol content (BAC) of 0.02 or higher.

Refusal of Alcohol Testing

Refusing to submit to an alcohol test or controlled substance test is a form of prohibited conduct.

How a DOT Alcohol Test Works

A Screening Test Technician (STT) or a Blood Alcohol Technician (BAT) conducts DOT alcohol tests using an Evidential Breath Testing (EBT) device, more commonly known as a breathalyzer. The STT or BAT establishes a private area for employee testing and will show each employee their results. If their BAC is above a 0.02, then it is considered a positive test result. In this case, the STT or BAT must perform a second test in 15-30 minutes to rule out a false positive. Any employee with a positive alcohol test result will need to cease safety-sensitive functions for 24 hours. They will also need to complete the return-to-duty process.

DOT-Required Alcohol Testing

DOT regulations for when to test for alcohol use are very similar to their guidelines for drug testing. The main difference is pre-employment testing. Whereas drug testing is always necessary before the start of employment, the DOT does not require pre-employment alcohol tests. However, motor carriers may choose to test for alcohol use during the pre-employment process.

The DOT and FMCSA require alcohol tests at the following times: 

Reasonable Suspicion

If a supervisor sees indications of alcohol use by a safety-sensitive employee, then they may initiate reasonable suspicion testing. A supervisor must undergo two hours of training in order to identify these signs of drug use or alcohol abuse by their employees.

Random Alcohol Testing

Motor carriers must perform random drug and alcohol tests. Companies must use a truly random process to meet DOT requirements and employees must be informed just before testing, leaving only enough time to stop safety-sensitive functions and report to the testing location.

Post-Accident Testing

After an accident while on duty, drivers must submit to drug and alcohol testing.


Following a drug or alcohol violation, employees will need to complete the return-to-duty process to resume safety-sensitive tasks.

Follow-Up Tests

After a violation, a substance abuse professional (SAP) will determine a schedule for follow-up drug or alcohol tests. This can include additional tests beyond what is necessary for the return-to-duty process.

We Can Help You Stay Compliant With alcohol Testing

A DOT-compliant drug and alcohol testing program is essential for any motor carrier. HDS Safety Services operates one of the largest random testing consortiums in Arizona. We can help ensure that you are compliant with all DOT and FMCSA regulations.

Contact us today to learn more about our drug and alcohol testing services.