Understanding advancements in employee drug testing: DOT approves oral fluid

10 August 2023

The DOT’s new ruling:

Effective since June 1, 2023, the Department of Transportation (DOT)’s new rule gives employers the option of using a urine or oral fluid test and indicates that oral fluid is permitted for all DOT modalities. It also has recently been approved for use by the Department of Health and Human Services (HHS) in federal workplace drug testing programs. Read more about the DOT’s rules and regulations here.

What is oral fluid testing?

Oral fluid testing is a type of drug test that examines an individual’s saliva and other oral fluid secretions to test for controlled substances in the body currently or recently used (within 48 hours of testing). Saliva/oral fluid is a “filtrate” of one’s blood, that is collected with an easy-to-use device that is placed in the donor’s mouth, or by providing a sample directly into a vial. This test can detect both parent drugs and metabolites, as drugs appear within minutes of ingestion. In terms of substance detection, the DOT oral fluid drug test panel includes the same drug categories as the urine DOT drug test panel. 

Benefits and fast facts

When it comes to drug testing, oral fluid testing offers a variety of advantages for employees and employers alike.

  • Quick and easy test for donors to participate in and technicians to administer—Making it more time efficient for all parties involved.
  • Directly observed specimen collection—Making samples of oral fluid less susceptible to any tampering and nearly impossible to adulterate, leading to increased test accuracy. 
  • Non-intrusive, comfortable testing—Eliminates need for private restrooms and same gender collections, reducing burdens for individuals undergoing testing and enhancing flexibility for employers.
  • Flexible options—Collections can be performed in house or at a Labcorp patient service center (PSC). Note that collections cannot be performed via video conference.
  • Oral fluid drug testing is mandatory for transgender and non-binary individuals who require a DOT Direct Observed collection.

Future impact:

The DOT’s new rule to allow oral fluid drug testing simplifies the DOT Direct Observed collection procedure for transgender or nonbinary employees, stating that “for all direct observation collections involving transgender or nonbinary individuals, employers must conduct an oral fluid test.” Additionally, it mandates that oral fluid tests are used when a DOT Direct Observed collection is required, but a same-gender collector is not available.

Oral fluid is suitable for all testing categories, whether that be preemployment, post-accident, random, or reasonable suspicion. When available, it can be incorporated into your current testing protocol as the primary specimen or as an alternative specimen (when a donor is unable to provide a urine sample).

Employer implementation: What does this mean for Labcorp and our clients?

This form of testing is not readily available for DOT employers to implement yet. This service will only become available when at least two laboratories are certified by the HHS that possess and utilize the same reagents and collection device to process the oral fluid tests.

In the coming months, Labcorp will continue preparations to roll-out oral fluid drug testing in our laboratories and collections in our PSCs. Further information will follow as it is available. If you would like to receive related communications/updates, please join our mailing list.

For non-DOT drug testing, Labcorp currently offers lab-based oral fluid drug testing with specimen collections in many of our company owned and operated PSCs nationwide. Learn more here.


Labcorp continues to offer a diverse array of employee drug testing. Explore our suite of options to maintain a drug-free workplace.

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