Why Reasonable Suspicion Training Needs a Refresher, No Matter Your Industry

Drug testing programs were built around a simple idea: catch it at the door. Pre-employment testing screens out active use before someone starts safety-sensitive work. Everything else, random testing, reasonable suspicion, post-accident testing, was supposed to be backup.

That assumption doesn't hold the way it used to. The newest workforce drug testing data shows a widening gap between what pre-employment testing catches and what's actually happening on the job, in construction, in transportation, in healthcare, everywhere companies test. And it's exposing a training gap that looks a little different depending on your industry, but comes down to the same thing: a lot of supervisors haven't been updated on what to look for in years.

What the Data Actually Shows About Drug Testing

The Quest Diagnostics Drug Testing Index, an annual analysis of more than 8 million workplace drug tests, is one of the most cited sources in the industry, and its 2025 report points to a shift worth paying attention to. Overall workplace urine drug positivity in the combined U.S. workforce dipped slightly, from 4.6% to 4.4%, the first decline after three years of elevated rates. That sounds like good news. Until you look at where the positivity is actually showing up.

In the general U.S. workforce, fentanyl positivity in random drug tests was 707% higher than in pre-employment tests in 2024 (1.13% compared to 0.14%). Zoom out to the last five years and the pattern holds: fentanyl positivity in random testing has run about 400% higher than pre-employment positivity over that period, a far wider gap than marijuana or other substances show. Marijuana's positivity rate in random testing, by comparison, has actually been about 42% lower than its pre-employment rate over the same stretch.

What that means, plainly: a meaningful number of employees are passing the test that gets them hired, then developing a fentanyl habit on the job. Pre-employment screening was never built to catch that. The other testing categories, random, reasonable suspicion, post-accident, are the ones picking up the slack.

Marijuana tells a related story. Post-accident positivity was 7.3% in 2024, just under the record high of 7.5% set in 2023. That's after years of workplace drug policy debate, more permissive state laws, and no shortage of employer education. The number hasn't moved much. Impairment on the job isn't just a hiring-stage problem. It's still very much a today problem.

None of this is confined to DOT-regulated trucking and transit. Construction's overall urine drug positivity rate was 4.7% in 2025. Healthcare's was 5.8%, up from 5.1% just four years earlier, and now sits among the highest of any industry Quest tracks. Both numbers run above the combined U.S. workforce average. Whatever industry you're in, if you're testing at all, this data is about your workforce too.

Where the Cost Actually Lands for Regulated Employers

For DOT-regulated employers, all of this eventually runs through the FMCSA Drug and Alcohol Clearinghouse, the national database that tracks violations for CDL holders.

As of the most recent reporting, the Clearinghouse shows more than 360,000 drug-related violations and nearly 8,900 alcohol-related violations reported since it launched in January 2020. Positive drug tests account for 82% of all violations reported. Every one of those records represents a driver pulled from safety-sensitive duty, a company that has to manage a return-to-duty process, and in a lot of cases, a collection site or a supervisor who was the first person to notice something was wrong.

If you're not DOT-regulated, the paper trail looks different, but it's still there. A missed reasonable-suspicion call can turn into a workers' comp claim, a negligent-retention lawsuit after an on-the-job injury, or a state audit that costs a construction firm or hospital system a drug-free-workplace premium discount it was counting on. The mechanism changes by industry. The exposure doesn't.

That's the part of the story that doesn't show up in a positivity percentage. A violation isn't just a number. It's a chain of people who had to do their part correctly: a collector who followed procedure, a supervisor who recognized the signs and made the call, whoever reviewed the result, and whatever return-to-duty process followed. If any one of those steps is weak, the whole chain is weaker. Weak links tend to show up during an audit or a dispute, not before one.

The Rules for Drug Testing Keep Changing

On top of a shifting drug landscape, the regulatory framework itself hasn't held still. DOT's oral fluid testing rule is the clearest example, since it's the most heavily documented, but it's not the only place this shows up.

The original final rule allowing oral fluid testing as an alternative to urine testing took effect June 1, 2023, but it couldn't actually be used because the Department of Health and Human Services hadn't certified the two laboratories required to process oral fluid specimens. Three years later, that certification still hasn't happened, which is why DOT published a new final rule on May 11, 2026, amending Part 40 again. The update allows employers to keep using directly observed urine collections as an interim measure until oral fluid testing becomes genuinely available, adds an 18-month grace period once a second certified lab is announced, and updates terminology throughout the regulation. It took effect June 10, 2026.

None of that changes what a collection site does today. But it's a reminder that this is a live regulatory environment, not a set-it-and-forget-it one. A rule that was supposed to modernize testing back in 2023 is still being patched in 2026, and every patch is one more thing a collection site, a TPA, or an MRO needs to know about and act on. Not just receive as an email that gets buried.

Non-DOT employers see their own version of this. State marijuana laws keep shifting what's testable and what isn't, and workers' comp drug-free-workplace statutes get amended more often than most HR teams realize. The specifics differ by state and industry. The pattern, rules changing faster than most training programs update, doesn't.

Supervisor Testing Training That's Required Once, Annually, or Not at All

Where the training requirement actually comes from depends entirely on who you are.

If you're DOT-regulated, it's federal. 49 CFR 382.603 requires everyone designated to supervise CDL drivers to get at least 60 minutes of training on alcohol misuse and 60 minutes on controlled substances, covering the physical, behavioral, speech, and performance signs of use. That's the training a supervisor relies on to determine whether reasonable suspicion exists under §382.307. And it's specific about one more thing: recurrent training isn't required. It's a one-time, 120-minute commitment, full stop.

If you're not DOT-regulated but participate in a state drug-free workplace program for a workers' comp premium discount, you might actually have it better. Georgia's program, for example, requires two hours of supervisor training initially and then an hour every year to keep the discount, not once. Iowa has the same requirements as Georgia. Alabama, Kentucky, Mississippi, Ohio, Tennessee, and Wyoming run similar voluntary programs.

And if none of that applies to you, meaning you're running your own drug-free workplace policy with no state or federal training mandate attached, the honest answer is: there's no requirement at all. Whatever training your supervisors have is whatever you decided to give them.

Three different starting points. Same underlying problem. Drug combinations shift. Presentation shifts. Whether a supervisor's training is one year old or ten, or whether it's required annually or never, the actual content of what they were taught to look for doesn't update itself. A construction supervisor trained on 2019's patterns is looking for 2019's signs. So is a trucking company's DER.

This isn't a criticism of any of these systems. A one-time requirement is still better than none, and plenty of companies go beyond whatever minimum applies to them. But keeping that knowledge current is on the employer, not the rule, no matter which rule, or lack of one, applies to you.

Aviation Already Figured This Out

There's a fourth version of this worth knowing about. 14 CFR Part 120, the FAA's drug and alcohol testing rule, covers pilots, mechanics, dispatchers, and air traffic controllers using the same collection procedures as everyone else under 49 CFR Part 40. The supervisor training requirement looks familiar too: sections 120.115(c) and 120.217(d) call for the same 60 minutes on drugs and 60 minutes on alcohol as trucking's 382.603. But FAA adds the one thing trucking's rule explicitly skips. Recurrent training, reported consistently across training providers as an annual requirement.

The results are hard to argue with. FAA tracks industry-wide random testing violation rates every year to decide whether minimum testing percentages need to rise. In 2024, the random drug test positive rate across the entire aviation industry was 0.816%. The alcohol violation rate was 0.131%. Set that next to the 4.4% overall positivity in the combined U.S. workforce cited earlier, and aviation's rate is roughly a fifth of it.

That's not proof that annual refreshers alone explain the gap. Aviation screens a smaller, more tightly credentialed workforce, and a positive test carries consequences, grounding, medical certificate review, that go beyond most other industries. But it's not nothing, either. Even trucking's own safety advocates have made this exact argument: in 2019, the Commercial Vehicle Safety Alliance petitioned FMCSA to add a recurrent training requirement to 382.603, every three years, citing rising drug-impaired driving. FMCSA didn't act on it. FAA had already built it in.

Three Honest Ways to Close the Gap

There's more than one reasonable way to handle this. None of them is automatically right for every collection site, and it's worth being straight about what each one actually does.

Live or in-person refresher courses. This is how most companies satisfy whatever baseline requirement applies to them, a DOT one-time course, a state's annual session, or an internal policy. These in person training programs are thorough, allow questions and are well understood by auditors. The catch is cost and logistics. Re-running a course across multiple supervisors, shifts, or locations adds up fast, and it's slow to update. A new drug trend doesn't change the material until the next scheduled session.

Written policy updates and memos. These are cheap, fast and easy to send the moment something changes. But a memo can tell a supervisor that fentanyl combinations are up; it can't show them what that actually looks like. And a email update is the easiest thing in a busy inbox to skim past.

Short Refresher Videos: Then there's the option we'd obviously bring up: short video refreshers. Worth being direct about what this is and isn't. A short video does not replace whatever mandatory training actually applies to your program, a DOT course, a state's annual requirement, or your own policy's minimum, full stop. What it's built for is everything after that baseline: a quick, consistent refresher that keeps recognition skills sharp, delivered the same way to every supervisor no matter the shift, location, or industry, and fast enough that a new regulatory change can reach a whole team in days instead of waiting for next year's session. Complement, not substitute.

Where to Start

If any of this data changed how you're thinking about your own program, here's a reasonable place to begin.

1. Figure out which category you're in: DOT-regulated (382.603 applies), a state program participant (check whether yours is one-time or annual), or unregulated (no mandate, but no excuse either). Then check when your supervisors actually completed the relevant training.

2. Build in some form of annual or biannual refresher, even an informal one, given how much drug trends have shifted since most supervisors were trained.

3. Put a distribution plan in place for the next regulatory change before it happens, so an update doesn't sit unread the way the last one might have.

4. If the gap you're looking at is consistency and speed, not the original course itself, that's a narrow, specific problem a short video refresher is built to solve.

Talk Through Your Specific Gap

Every program is a little different: different mix of supervisors, different shifts, different industries. There's no single right answer to the refresher question. If it'd help to talk through what this looks like for your program, or just see a sample video, we're glad to walk through it. Reach out here.

For more information you can also read our Drug and Alcohol Testing and Screening page.