Hair Follicle Drug Testing

What it is:
Hair follicle testing is a method used to detect drug use over a longer period of time—up to 90 days. A small hair sample is taken from the scalp (or body) and analyzed for drug metabolites that grow into the hair shaft.

How it assists:
This method is ideal for identifying long-term 
patterns of drug use. It’s especially helpful in 
pre-employment screening or when employers want to detect habitual substance use rather than recent, one-time usage.

Why it's used:

  • Longer detection window (up to 3 months)
  • Harder to adulterate or cheat
  • Provides a clearer picture of consistent drug use

DOT Approval:
Hair follicle testing is not currently approved by 
the U.S. Department of Transportation (DOT) for 
regulated testing under 49 CFR Part 40. However, employers may still use it for non-DOT testing or for internal screening purposes.

Oral Fluid (Saliva) Drug Testing

What it is:
Oral fluid testing uses a mouth swab to collect saliva and detect recent drug use—typically within 12 to 48 hours. It’s a non-invasive, observed collection method.

How it assists:
This method is excellent for detecting very recent drug use and is commonly used in post-accident or reasonable suspicion testing, where timing is critical.

Why it's used:

  • Easy, fast, and non-invasive
  • Ideal for onsite or mobile testing
  • Reduces the chance of cheating
  • Detects very recent drug use

DOT Approval:
As of June 2023, Oral Fluid Drug Testing is 
approved by DOT, but only if the lab is certified by HHS and listed on the approved list. However, few labs are currently certified, so urine testing 
remains the most common DOT method

Saliva testing is still widely used for non-DOT 
programs and employer-initiated screening.

When Should Employers Use These Methods?

  • Hair Follicle Testing: Great for pre-
    employment, periodic testing, and long-term detection
  • Oral Fluid Testing: Best for post-accident, reasonable suspicion, and random onsite testing
  • Both are valuable tools for employers who want a more complete and flexible drug testing program.

Know More. Test Smarter. Protect Your Workplace.

Hair Follicle & Oral Fluid Drug Testing

4Tymesme Mobile Drug Testing Offers:

  • Hair follicle testing with secure lab processing
  • Oral fluid (saliva) testing with fast collection
  • Mobile service available for both methods
  • DOT and non-DOT testing compliance guidance

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