There’s been a new wave of discussion in the trucking industry—and it centers on hair testing for drugs. A recently proposed bill in Congress could reshape how we screen drivers and how results are shared through the FMCSA Drug & Alcohol Clearinghouse.
At Focused Compliance Group, we’re keeping a close eye on the issue. Whether you operate a large fleet or run a small business, this could impact how you handle drug testing and compliance moving forward.
What’s New?
Congressman Eric Crawford recently introduced a bill (H.R. 4320) that would allow positive hair drug test results to be entered into the DOT’s Drug & Alcohol Clearinghouse. The DOT’s Drug & Alcohol Clearinghouse also tracks alcohol testing results as part of its comprehensive approach to safety-sensitive positions. Right now, only urine and oral fluid test results are accepted in the Clearinghouse system.
Hair testing isn’t new—many carriers already use it internally. What’s new is the push to make those results count on the federal level.
Why Some Want Hair Testing Included
Supporters argue that hair follicle testing reveals more. Unlike urine tests, which detect drugs used within the past few days, hair drug tests can detect drugs over a range of up to 90 days, depending on hair growth rates. This extended detection window allows employers to determine a more complete picture of a driver’s habits and long-term substance use.
During the collection process, a hair sample is collected directly from the person’s head. If the individual is bald, body hair may be collected as an alternative. Only a small amount of hair is needed—about 90-120 strands or approximately 100 milligrams—and the sample must cover a sufficient area to ensure accuracy. The sample is physically collected from the individual and cannot be substituted from other sources, making it nearly impossible to cheat the test.
Drugs are incorporated into the hair as they enter the bloodstream and become part of the hair follicles during growth. The concentration of drug metabolites in the hair can be affected by external factors, but typical shampoos and styling products do not usually affect test results. Hair follicle tests compare favorably to other methods because they can detect a wide range of substances, including marijuana, cocaine, amphetamines, ecstasy, opiates, and PCP.
Large carriers like J.B. Hunt and Schneider say that hair follicle tests help them avoid hiring employees who may have a history of substance use—even if they pass a standard DOT urine test. They’ve found that some employees pass a urine test but fail a hair follicle test, which means they might still be using drugs off-duty or in the recent past. Employees may be tested as part of workplace rules, and employers rely on hair follicle testing for compliance and safety.
Another argument in favor is reliability. Because the sample is collected directly and the process is tightly controlled, it is nearly impossible to tamper with or cheat a hair follicle test. This adds another layer of confidence for safety-sensitive positions, where any risk can have serious consequences.
Note: If a hair follicle test result is positive or inconclusive, a retest may be performed to confirm the findings and rule out false positives.
How Hair Drug Test Works
A hair drug test, often referred to as a hair follicle drug test, is a highly effective method for detecting drug use over an extended period. The process begins with the collection of a small hair sample—usually about 90 to 120 strands, or roughly 100 milligrams—from the person’s head, typically close to the scalp. If head hair isn’t available, body hair can be used as an alternative. The collector carefully secures the hair sample in foil to maintain its integrity and completes the necessary chain of custody documentation before sending it to the laboratory.
Once at the lab, the hair follicle drug testing process focuses on the hair matrix, which is the innermost part of the hair shaft. When a person uses drugs, substances and their metabolites enter the bloodstream and become embedded in the growing hair. This means that as hair grows, it incorporates a record of drug use, making hair follicle drug tests particularly valuable for detecting substances like marijuana, cocaine, methamphetamine, heroin, and more.
The laboratory analysis typically involves a two-step testing process. First, an initial screening test is performed to detect the presence of drug metabolites in the hair sample. If the screening is positive, a confirmatory test is conducted to ensure the results are accurate and reliable. This thorough approach helps minimize the risk of false positives or negatives.
One of the main advantages of hair follicle drug tests compared to urine drug testing is the extended detection window. While urine tests can only detect drug use from the past few days, hair follicle tests can reveal substance use from up to 90 days prior. This makes hair drug testing a preferred choice for employers and law enforcement agencies who need a comprehensive view of a person’s drug history. Additionally, hair samples are generally much harder to tamper with than urine samples, reducing the risk of manipulation and increasing the reliability of the results.
Overall, hair follicle drug testing offers a secure, efficient, and accurate way to screen for drug use. By analyzing hair samples, employers and agencies can better ensure workplace safety, comply with regulations, and make informed decisions about hiring and ongoing employment.
The Other Side of the Argument
Not everyone is on board.
One of the biggest concerns is fairness. Hair testing doesn’t detect current impairment—it only shows historical use. A driver who smoked marijuana a month ago on their personal time might still fail a hair test today, even though they’re clean and safe to drive now.
There are also worries about bias. Some studies suggest that hair color and texture can affect drug retention, meaning that people with darker or coarser hair may be more likely to test positive. Religious groups, like Sikh drivers, who maintain uncut hair, may also face unique challenges if hair testing becomes a requirement.
Another key concern is that federal health agencies—like HHS and SAMHSA—haven’t finalized scientific guidelines for hair testing. Until those standards are published, some believe it’s premature to make hair results part of the federal record.
What It Means for the Clearinghouse
As it stands today, FMCSA only accepts urine and oral fluid tests in the Clearinghouse. That means even if a driver fails a hair test with one company, there’s no federal record of it—allowing them to apply elsewhere and potentially get hired.
If H.R. 4320 passes, that could change. Carriers would be allowed, or even required, to upload positive hair test results into the Clearinghouse. That would give employers access to more data about a driver’s drug history—but it also raises questions about privacy and due process.
FMCSA has previously declined to include hair testing, citing the lack of final guidance from HHS. This new bill attempts to bypass that roadblock by making a legislative change.
How This Could Affect Trucking Companies
Carriers who already use hair testing may finally be able to report positive results to the Clearinghouse, creating a more level playing field. That could help prevent drivers from job-hopping after failing a non-DOT test.
On the other hand, companies that haven’t adopted hair testing might feel pressure to do so to stay competitive or avoid missing critical red flags. That could lead to higher testing costs, legal questions, and potential pushback from drivers and advocacy groups.
The industry could see a wave of policy reviews, legal challenges, and training updates—especially if the bill gains momentum.
Where We Go From Here
The debate over hair testing isn’t just about science—it’s also about values. Supporters see it as a tool for greater safety. Critics see it as a potential overreach that could penalize drivers unfairly.
One thing is clear: this issue isn’t going away.
For now, carriers should stay informed, revisit their internal policies, and prepare for the possibility of changes to federal reporting rules. Whether or not H.R. 4320 becomes law, the conversation around drug testing is evolving—and being proactive could give your business an edge.
If you have questions about DOT testing requirements, driver compliance, or the Clearinghouse, Focused Compliance Group is here to help. We’ll continue monitoring developments and providing the guidance you need to stay compliant and protect your team.