Learn More About Hair Follicle Drug Testing

Statistics show that a fair number of truck drivers who undergo drug and alcohol tests fail. These impaired drivers can cause severe accidents by operating a heavy vehicle under the influence. To combat drunk and drugged driving, the SAMHSA (Substance Abuse and Mental Health Services Administration) published new recommendations relating to hair follicle drug testing. The guidelines detail the technical protocols for hair follicle drug tests. There is a movement for these tests to be required for DOT mandated safety-sensitive employees in the future.

Hair Follicle Drug Testing Facts

Hair follicle drug tests are gaining popularity because they allow medical experts and authorities to detect drugs consumed up to 90 days before testing. On the other hand, most drugs are only detectable in urine for a week or less. If a DOT mandated safety-sensitive employee is a repeated drug user, the employee’s hair follicles could retain traces of the drug even longer than 90 days. The drug test detects the following drugs:

  • Marijuana
  • Codeine, Morphine, and Acetylmorphine (Opiates)
  • Cocaine
  • Methamphetamine
  • Phencyclidine

Medical experts specializing in drug testing assert that authorities will only need 100 milligrams or 1.5 inches of hair from the root end to carry out the test successfully. However, the guidelines proposed a shorter (1”) 100 mg hair split specimen than the current industry standard of 1.5-inch, 100 mg, single-specimen collection. The collector must collect approximately 120 strands of hair for lab testing purposes. The experts use procedures like the Enzyme-Linked Immunosorbent Assay (ELIZA) and other similar tests to detect and measure traces of illicit drugs in the employee’s hair follicles.

How Long Do Drugs Stay In Your System?

The range for urine-based drug tests is usually anywhere between 2 to 10 days. In urine tests, the more potent drugs may show up for up to 10 days after the date of use. As mentioned above, hair follicle testing can detect drugs up to 90 days out. However, two factors impact the test window in the case of hair follicle drug tests:

  • The potency of the drug
  • The frequency and intensity of drug use

Therefore, if a DOT-mandated employee is a regular drug user, the tests are likely positive from hair follicle drug testing.

Contact Us for Fast and Effective SAP Services

If you are DOT mandated safety-sensitive employee who failed a drug and/or alcohol test, SAP Referral Services can help with fast access to a SAP in your area. Connect with a SAP now to begin the return-to-duty process and get back to work. Click here to learn more about our FastTrack Enrollment and get started on your journey.


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.