DOT Drug Testing Guide

Department of Transportation Drug Screen

Important InformationThis information is for educational purposes only. We never invite or suggest the use, production or purchase of any these substances. Addiction Resource and it’s employees, officers, managers, agents, authors, editors, producers, and contributors shall have no direct or indirect liability, obligation, or responsibility to any person or entity for any loss, damage, or adverse consequences alleged to have happened as a consequence of material on this website. See full text of disclaimer.

Department of Transportation (DOT) takes safety very seriously across all modes, from roads to railroads to water to air; overland as well as underground. To ensure that their employees are 100% alcohol- and drug-free, they have formulated a whole testing program which has pretty strict standards.

What is DOT Drug Screen?

Department of transportation logoThe Omnibus Transportation Employee Testing Act of 1991 defines the rules for DOT physical and drug screen for the transportation employees. These regulations are applicable to all the transportation employees, service agents, and safety-sensitive transportation employees. Rough estimates tell us that there are 10 million people who work in these fields. The Office of Drug and Alcohol Policy and Compliance (ODAPC) has the authority to publish, implement, and interpret these rules.

Help Line Woman

Hope Without Commitment

Find the best treatment options.
Call our free and confidential helpline

Most private insurances accepted

Marketing fee may apply

What jobs are subject to DOT drug testing?

  • Flight crews, flight attendants, and flight instructors
  • Commercial vehicle drivers who are Commercial Motor Carriers, such as Commercial Driver’s License holders
  • Maritime jobs such as the crew operating a commercial vessel
  • Jobs in operations, maintenance, and emergency response
  • Transit jobs such as vehicle operators, controllers, mechanics and armed security
  • Railroad workers

Who is Subject DOT Drug Testing?

Any safety-sensitive employee is subject to DOT drug & alcohol testing. Here’s a quick overview of the employees marked as safety-sensitive operators that are subject to DOT drug and alcohol testing.

  • Aviation such as flight crews, flight attendants, flight instructors
  • Commercial Motor Carriers such as Commercial Driver’s License (CDL) holders who drive commercial vehicles
  • Maritime such as crewmembers operating a commercial vessel
  • Pipelines such as folks working in operations, maintenance, and emergency response
  • Transit such as vehicle operators, controllers, mechanics and armed security
  • Railroad

What Drugs Does DOT Test for?

These drug groups are tested for by Department of Transportation.

When Can I be Tested?

Safety-sensitive employees can be tested by the department in several different situations:

  • Pre-employment
  • Post-Accident
  • Return-to-duty
  • Reasonable Suspicion/Cause
  • Follow-up
  • Random

Can you refuse a DOT drug test?

Refusing the DOT drug test can have severe consequences. Take the test even if you believe that you have been unfairly selected, then subsequently write a letter to your employer or the appropriate DOT agency to express your concerns.

What if my drug test comes back positive?

If your drug test comes back positive, you will be dismissed from performing safety-sensitive functions. You may lose your license or certification to perform your job. You’ll have to undergo an evaluation by a Substance Abuse Professional and complete a counseling or treatment and provide a negative result upon your return.

What Types Of Test Does DOT Administer?

For alcohol testing, they require a breath test, and for all the other drugs, urine test or urinalysis is used.

How is an Alcohol Test Administered?

To ensure validity and confidentiality, a Screen Test Technician or Breath Alcohol Technician will use a device approved by the department to test you after you sign the Step #2 of the Alcohol Testing Form. If your BAC is less than 0.02, your test is considered negative and no further action is required, other than the tester providing you and your employer a copy of the result. If your BAC is greater than 0.02, a confirmation test will be administered after a period of 15 minutes, but no later than 30 minutes of taking the first test. Only a Breath Alcohol Technician can administer this test, and you won’t be allowed to eat or drink anything, or leave the area. If confirmed, your test will be considered positive and reported to your employer.

How is a Urine Drug Test Administered?

The urine drug testing process is done the same way by all the agencies that may require the test. It has three components: collection, testing, and review by the Medical Review Officer.

Can I Refuse a Test?

Even if you believe that you are unfairly selected or have any other reason for not yielding to a dot drug screen, take the test anyway. Because if you refuse the test, it can have worse consequences. The rule of thumb is to take the test, and then write a letter to your employer or the appropriate DOT drug agency and express your concerns. You can easily find the contact details of the agencies online. Just make sure to contact your employer or the agency as soon as possible after the test.

What if I Test Positive?

As soon as you test positive, or are found guilty of violating any of DOT drug screen regulations, you’ll be stopped from performing safety-sensitive functions. The good thing is that DOT doesn’t make any hiring or firing decision, they will only report it to your employer. You might, however, lose your license or certification to perform your job. Moreover, you won’t be allowed to return to your duties until you have undergone an evaluation by a Substance Abuse Professional (SAP), complete a counseling or treatment recommended by the SAP and provide a negative result upon your return. What’s more, you’ll be tested at least six more times within the 12 months of your return.

View Sources


Leave a comment

  • Gank
    Can I pass a dot using certo I haven’t smoked in about 3 and a half weeks
    • J
      I hadnt smoked for 30 days, then I smoked 2 puffs, then 7 days later I smoked 1 tiny puff due to peer pressure because I wanted the guy to like me. I now have a test 6 days after that 1. I bought dollar store mj tests yesterday (day4 after 1) it dropped on the floor in the mcdonalds bathroom and i blew it off and peed in a cup and it came out positive. The next day (today day 5 after the 1 puff) I took another test after I first woke up, the line was faint but visible. I bought 4 more tests and also bought this $40 walgreens test that I will take tomorrow morning. Im going to drink a lot of water and take these tests for hopefully a stronger line. I dont want any mishaps what if they say “oh its a faint line —fail, or oh its 45ng/ml not 50– fail. “ then they do the confirm test of 15 and thats a for sure fail. Anyway, i dont want it to be too diluted because that would be a fail. I didnt even want to smoke, I dont even smoke. Well see what happens. im 155lbs, 5’8 bmi is 24 but im fatty not avg. female
  • Tanner Hansen
    After failing a DOT pre employment urine test, does the employer your applying for see the exact details, i.e. what drugs you tested positive for? And if they do find out the details are they aloud to tell everyone in the company the details or just that I failed the pre-employment?
  • Sean Michael McGuigan
    Does a DOT drug screen include a hair follicle test?