Hair Testing for Illegal Substances is Gaining Greater Interest

By Dr. Dave Thorpe

In January of this year, six big fleets asked FMCSA to use hair testing for illegal substance screenings.  This continues a movement outlined in the Fixing America’s Surface Transportation Act (FAST Act) that was signed into law on December 4, 2015 by then President Obama.

The six companies are J.B. Hunt Transport, Schneider National Carriers, Werner Enterprises, Knight Transportation, Dubre Logistics and Maverick Transportation.  They have asked for an exemption to the current requirement for Urinalysis required by the FMCSA because they believe their data “demonstrates that hair analysis is a more reliable and comprehensive basis for ensuring detection of controlled substance use.”


If granted, the exemption will allow the six carriers to use hair testing for pre-employment screening exclusively instead of urine testing.  Currently only urine testing is allowed by the FMCSA.  If approved, drivers who have positive results with hair testing will not be able to perform safety sensitive functions until completing a return-to-duty process – which is the same process required with positive urine testing results.


Hair testing is considered to be more effective in assessing long term drug use.  It covers a period of approximately 90 days, but this can vary based on the growth rate of a person’s hair.  This as opposed to urine screening which, based on the drug being tested, only detects illegal substance use from a few days to up to maybe a few of weeks typically.

Also, in comparison to urinalysis drug testing, cocaine, PCP, opiates and methamphetamine have proven hair analysis far more effective than urine testing in identifying low-level drug use over an extended period of time since these are normally out of the bloodstream in within 3-7 days.  The detection of marijuana is currently less sensitive than the other drugs in identifying low level drug users, but is considered approximately equal to urinalysis in identifying marijuana users.


Yes, there are a few limitations worth noting.  One relates to the inability to detect recent drug use as it takes anywhere from four to ten days for the hair containing the drug to grow far enough from the scalp.  This may make urine testing an additional requirement anyhow.  Also, there may exist a color bias as hair melanin concentration can affect drug incorporation of basic drugs being tested.  There is also the possibility of environmental contamination from smoked drugs even if the driver tested is not a drug user.

Another area of significant concern is the increase in the cost of performing this type of testing to the trucking industry.  Hair testing can cost as much as three to five times greater than what the typical costs are for urine testing.  Some motor carriers appear to feel that this added cost is worth the detection of long term users and its effect on their FLEETS.  The FMCSA feels this will enhance safety on the roads also based on its inclusion in the FAST Act.  Will this added cost be a benefit to the industry and the general public?  Only time will tell.


Yes again!  The Owner-Operator Independent Drivers Association (OOIDA) has spoken out against the use of hair testing, because it believes the method is more costly and has multiple limitations as mentioned above.

Author: passmyphysical

Pass My Physical (PMP) is a DOT medical exam management platform that enables motor carriers to increase operating revenue, better fulfill regulatory requirements and reduce operating expenses. Why Pass My Physical?? (1) More operating revenue • Keep freight moving with more medically qualified drivers • Secure better freight rates by improving SMS scores (2) Lower regulatory administrative burden • Gain insight into the fleet’s certification status • Proactively respond to impending expirations (3) Less operating expense • Reduce medical certification costs by eliminating the need to retake the exam • Secure better insurance rates by improving SMS scores. Pass My Physical’s DOT medical exam management platform enables motor carriers to effectively eliminate most delays related to their drivers’ DOT physical exam. For more information visit our website at; OR contact us directly at

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