Oral Fluid Testing: A New Option in DOT Regulations

July 9, 2025

Ophthalmologist's Department

The Department of Transportation (DOT) now allows oral fluid testing as part of its drug testing regulations. This new option gives employers more flexibility while maintaining the integrity of the testing process. In this blog, we’ll explore what oral fluid testing entails, how it compares to traditional urine testing, and what employers and employees need to know about these changes.

Employer Flexibility: Mix and Match Testing Methods

One of the biggest highlights of the new oral fluid testing rule is that employers now have the option to decide which testing method to use.

Employers can:

  1. Stick with urine testing, except for non-binary employees who require oral fluid testing for observed collections.
  2. Use oral fluid testing for specific cases, such as pre-employment or post-accident testing.
  3. Combine both methods, such as using oral fluid testing for pre-employment and urine testing for random or follow-up testing.

Key Point: The flexibility applies across all DOT agencies (e.g., FMCSA, FAA, FTA, FRA, Coast Guard), making it a universal option under Part 40 regulations.

How Oral Fluid Testing Works

Oral fluid testing involves collecting saliva from the donor using a simple mouth swab. It’s scientifically backed as forensically defensible and viable, thanks to guidelines from the Department of Health and Human Services (HHS).

Detection Times

One notable difference between oral fluid and urine testing is the detection window:

  1. Oral Fluid Testing: Detects recent drug use, with a window starting about 15 minutes after use and lasting up to 72 hours for cannabis.
  2. Urine Testing: Captures drug use history, with detection starting at least 24 hours after use and lasting up to 67 days for substances like cannabis.

Example: For post-accident or reasonable suspicion testing, oral fluid testing offers an immediate window of detection that may be preferable. However, for random or follow-up testing where patterns of drug use need to be identified, urine testing might still be the better option.

Key Differences: Urine vs. Oral Fluid Testing

Important Note: Despite its shorter detection window, oral fluid testing is not a measure of impairment just like urine testing. Employers must avoid using test results to claim that an employee was "under the influence."

Benefits of Oral Fluid Testing

  1. Faster Results: Oral fluid testing can be conducted at the scene of an accident or on-site, avoiding delays and long travel times to collection centers.
  2. Reduced Privacy Concerns: Since it doesn’t require observed urine collection, oral fluid testing eliminates many privacy-related challenges.
  3. Lower Tampering Risk: Unlike urine samples, oral fluid samples are harder to adulterate or substitute.

Challenges of Oral Fluid Testing

While oral fluid testing has its advantages, employers should also be aware of its limitations:

  1. Short Detection Time: Employers looking to detect long-term drug use patterns may find urine testing more effective.
  2. Regulatory Updates Required: Employers must update their policies to reflect the use of oral fluid testing.

What Employers Need to Do

To incorporate oral fluid testing into their programs, employers should:

  1. Review the Regulations: Understand the pros and cons of both testing methods and determine which fits their needs best.
  2. Update Policies: Amend policies to include oral fluid testing, including the required provision for non-binary employees that mandates oral fluid testing for observed collections.
  3. Train Employees: Ensure staff understand what to expect during oral fluid testing and how it fits into the company’s program.
  4. Prepare for On-Site Testing: If oral fluid collections will be done on-site, ensure safety personnel are trained and certified to perform collections.

Karishma Sarfani

Karishma is a Qualified Substance Abuse Professional (SAP) with a background in mental health and substance abuse counseling, holding credentials as an MS, LCDC, ICADC, CADC II, CSAC, CASAC II, LPC, and EMDR-trained therapist. Inspired by personal experiences with addiction and mental health challenges in her community, she has dedicated her career to supporting individuals on their journey to recovery and success.