Hair-follicle testing is considered by many to be more accurate than urinalysis. This type of testing is able to detect drug use over a much longer period of time and is therefore better at unveiling chronic drug use. It is the only drug-testing method at this time that can provide a 90-day history of drug use. Because of this long detection window, hair testing also provides a greater number of positives than urine testing.

Urine testing, however, is the go-to method for reasonable suspicion drug tests and post accident testing. Unlike hair testing, urine tests are able to detect very recent use. Regardless, many employers prefer to test employees using hair rather than urine because of the availability of chemicals and devices to assist in receiving a false negative on a urine test.

Currently, commercial motor vehicle operators are only allowed to test employees using urine testing.  But that is about to change with the addition of The Fixing America’s Surface Transportation Act, which was signed into law in December, 2015. This act directs the U.S. Department of Health and Human Services to issue specific and technical guidelines for the use of hair testing commercial motor vehicle drivers, guidelines which are mandated for publication this year.

Section 5402 of the act states that “motor carriers shall be permitted to use hair testing as an acceptable alternative to urine testing in conducting pre-employment drug screens and in conducting random testing for the use of a controlled substance if the driver was subject to hair testing during a pre-employment screening.”

The act allows an exemption from hair testing to truck drivers with established religious beliefs that prohibit the removal or cutting of hair. Still, this change does not come without its own set of challenges. These challenges include retesting concerns and potential violations under the Americans with Disability Act. 


Roy Maurer. “Enhanced Drug Testing for Commercial Drivers Coming This Year – See More At: Https://” Society for Human Resource Management. Web.