All You Need To Know About DOT Drug Testing Rules

In 1991, the United States Congress passed the Omnibus Transportation Employee Testing Act, as there was a dire need for the transportation industry to ensure their safety-sensitive employees were drug and alcohol free. “49 CFR Part 40, or Part 40 as we call it, is a DOT-wide regulation that states how to conduct testing and how to return employees to safety-sensitive duties after they violate a DOT drug and alcohol regulation. Part 40 applies to all DOT-required testing, regardless of mode of transportation.” The DOT drug testing rules state that if an employee fails a drug and/or alcohol test they will immediately be removed from their safety-sensitive duties and must be referred to a Substance Abuse Professional (SAP) in their area.

DOT Drug Testing Rules: When Does an Employee Have to Test, and for What?

While each DOT Agency-specific regulation gives more details regarding who is subject to testing, all safety-sensitive employees should expect to undergo alcohol and drug testing for the following reasons:

  • Pre-employment
  • Random selection
  • Reasonable suspicion
  • Follow up testing
  • Post-accident

DOT-mandated safety-sensitive employees will be tested for the following: Marijuana, Cocaine, Opioids (Codeine, morphine, heroin, hydrocodone, hydromorphone, oxycodone, oxymorphone), Phencyclidine (PCP), Amphetamines, Methamphetamines, and Methylenedioxymethamphetamine (MDMA).

An employee working within the FRA, “for FRA Part 219 Subpart C qualifying Post-Accident Testing you will be tested for more than the five drug categories listed above.”

Do the DOT Drug Testing Rules Apply to Refusal?

Failing the drug test and refusing to take the drug test carry the same penalties. Under DOT regulations, employees who either fail or refuse to take the test must be removed from their safety sensitivity positions immediately. In order to return to your safety sensitive duties you must be evaluated by a Substance Abuse Professional (SAP) and successful comply with the return-to-duty program.

Finding a DOT Qualified SAP

It is important to find a DOT qualified SAP quickly in order to successfully regain employment and avoid unemployment. In order for an employee to find a SAP in their area, they can either seek out the services of a service agent, like SAP Referral Services, or look through a SAP list. While a SAP list might seem like a good idea at first, it typically ends up taking more time to set up an appointment with a SAP, as the employee will be required to review the SAPs credentials and make sure they are all up-to-date.

SAP Referral Service is a good place to start for safety sensitive employees that are in need of a DOT qualified SAP. When you enroll with SAP Referral Services, your SAP evaluation is typically scheduled within 72-business hours. Get in touch today at 410-668-8110 to enroll.


SAP Referral Services (SRS) is the leading facilitator for mandated substance abuse evaluations. SRS maintains an extensive network of qualified providers in more than 3,000 locations nationwide for testing violations that originate from any of the DOT’s modes including FMCSA, FAA, FRA, FTA, USCG and PHMSA, or a company’s internal drug and alcohol testing policy.

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