• faq dot

DOT Drug Testing FAQ

Frequently Asked Questions about Department of Transportation (DOT) Drug Testing

Most people can find that the U.S. Department of Transportation (DOT) drug testing rules can be daunting. Below are some of the frequently asked questions regarding the rules on drug testing for the U.S. Department of Transportation. The regulations on conducting drug testing under the U.S. Department of Transportation can be found in Title 49 CFR §382 for Federal Motor Carriers.

Q: Are there any special requirements my DOT Drug Testing facility should have?

Yes. Any testing Drug Testing facility that performs US Department of Transportation (USDOT) drug testing must be trained on specialized procedures, perform practical testing scenarios and receive a certificate of completion for both Alcohol and Drug Testing. Make sure the company you use has that training.The DOT requires the Federal Motor Carrier Safety Administration (FMCSA) to require random drug testing of truck drivers who operate vehicles that weigh over 26,000 as well as drug test drivers of buses that carry more than 16 passengers, including the driver. The Office of Pipeline Safety Pipeline and Hazardous Materials Safety Administration (PHMSA) require pre-employment drug testing and random drug testing for pipeline construction workers. Alcohol Testing and Drug Testing are performed "for-cause" and after an accident or incident.The US Coast Guard regulations require drug testing of seamen on merchant fleets and requires the crew of passenger vessels to submit to drug testing.

Q: Under the FMCSA how long do I have to keep DOT drug-testing records?

Five Years:

  • Alcohol test results indicating a Breath Alcohol Concentration (BAC) of 0.02 or greater
  • Verified positive drug test results
  • Refusals to submit to required alcohol and drug tests
  • Required calibration of Evidential Breath Testing (EBT) devices

Two Years:

  • Records related to the collection process and required training

One Year:

  • Negative and canceled controlled substance test results
  • Alcohol test results indicating a BAC of less than 0.02

Indefinite Periods:

  • Records related to the training and education of breath alcohol technicians, drug screen collectors, supervisors and drivers, shall be maintained until two years after they no longer perform those functions.

Q: What percentage of random drug testing do I need to perform on commercial drivers?

You are required to perform random drug testing on 50% percent of drivers for controlled substances (drugs) and 10% percent for alcohol.

Q: Is a pre employment drug test required if a driver returns to a previous employer after their employment has been terminated?

Yes. A drug test must be performed any time employment has been terminated for more than 30 days and the exceptions under 49 CFR §382.301(c) (pre-employment testing) were not met.

Q: As an employer can I put my non-DOT covered employees in a random pool with my DOT covered employees?


Q: If I suspect a driver has been drinking on the job, within what specific time do I have to test a driver?

You must test the driver within two hours. If you delay more than two hours you must document the reason for the delay. After eight hours you can no longer test the driver for alcohol. 

Q: What circumstances is considered a "refusal to test"? 
Under 49CFR§40.191 the company will follow DOT drug and alcohol guidelines when a refusal to take a required drug test occurs. A refusal will be defined as:

  1. Failure to show up for any alcohol or drug test within a reasonable time after being directed to do so by the company. 

  2. Failure to provide a urine specimen for any drug test required by this part or DOT agency regulations; [modal regulations] 

  3. In the case of a directly observed or monitored collection in a drug test, failure to permit the observation or monitoring of your provision of a specimen
  4. Failure to provide a sufficient amount of urine when directed, unless the physician has determined, through a required medical evaluation, that there was an adequate medical explanation for the failure 

  5. Failure to drink fluids as directed by the collector following a failure to provide a sufficient amount of urine 

  6. Failure to undergo an additional medical examination, as directed by the MRO as part of the verification process, or as directed by the physician conducting the evaluation as part of the "shy bladder" procedures of this part; or
  7. Failure to cooperate (e.g., leave the test site before the collection process is completed, refuse to empty pockets or boots) with any part of the testing process. 

  8. If the specimen is found to have been adulterated or substituted. 

Q: What are the rules on a post-accident alcohol test? 
No driver required to take a post-accident test shall use alcohol for 8 hours following an accident, unless they have undergone a post-accident alcohol test, whichever comes first.


end faq

If you have any other questions regarding DOT Drug Testing or would like more information please call us at 1-800-690-4362 or fill out the form below to be contacted by one of our knowledgeable and friendly DOT Drug Testing Consultants.

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4045 E. Guasti Rd. #215
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