Why Employers Test for Drugs: Managing Risk, Safety, and Workforce Readiness 

This is Part 2 of a WorkCare series on workplace drug and alcohol testing programs. In this post, we examine the “when,” “who,” and “how” of occupational health drug testing, and why the answers matter more than ever in today’s complex risk environment.  (Read Part 1 here if you missed it.)

In 2022, a record-high 525 workers died from drug overdoses on the job, a 13% year-over-year increase, according to the Bureau of Labor Statistics. 

Meanwhile, opioid prescriptions remain widespread, marijuana legalization continues to evolve, and synthetic drugs like fentanyl are contributing to a surge in accidental poisonings. All of this is hitting employers where it hurts: safety, compliance, and cost. 

Here’s the thing: occupational health drug testing isn’t just about catching users; it’s about prevention, deterrence, and confirming fitness for duty. A well-run substance testing program sends a message: We take occupational health and safety seriously here. 

Testing Triggers: What Seasoned Leaders Watch For 

The use of illegal drugs and misuse of prescription drugs, particularly opioids, is identified as a persistent public health risk in a March 5, 2025, report by the U.S. Government Accountability Office. The National Council on Alcoholism and Drug Dependence has estimated that substance abuse costs U.S. employers a $81 billion+ per year. And in a study, the National Safety Council and NORC at the University of Chicago found that U.S. employers annually spent an average of $8,817 per employee with an untreated substance use disorder (SUD), while they could have saved $8,500 on an employee with a SUD by suIf you’re managing a drug-free workplace policy, you already know when occupational health drug testing should happen. But sometimes the challenge isn’t knowing the rules — it’s navigating the gray areas. Let’s recap the main triggers and review some real-world reminders: 

Pre-Employment 
A failed screen is easy. But what about a dilute sample? What if a candidate has a valid prescription? WorkCare can help guide the next steps and support regulatory compliance. 

Post-Accident 
Timing is everything. Wait too long, and the window to detect impairment closes. Department of Transportation (DOT) guidance is clear, but internal policies should be just as tight for non-regulated roles in drug-free workplaces. 

Random Testing 
Recognized by both the Substance Abuse and Mental Health Services Administration (SAMHSA) and the DOT as an effective deterrent, especially in safety-sensitive environments. But even random programs need documentation to show fairness and true randomness. 

Reasonable Suspicion 
Employers often stumble when it comes to for-cause or reasonable suspicion testing. Are your supervisors trained to spot potential impairment, question employees, make referrals, and document incidents in ways that will hold up under legal scrutiny? 

Return-to-Work/Follow-Up 
These aren’t just check-the-box moments. They’re critical signals to the employee and the team that recovery is supported and safety remains the priority. 

Matching Risk, Role, and Regulation with Workplace Drug Testing 

An occupational health drug testing program is not a one-size-fits-all proposition. It needs to be adaptable to fit the situation. For instance, an occupational health and safety manager might need immediate substance detection to determine whether an employee should be instructed to stand down, while a risk officer may care more about a long-term use pattern in the entire employee population. Choosing the right test method should be less about the cost (“What’s the cheapest way to test)?” and more about “What best fits with our risks?” Here’s how they stack up: 

• Urine: Tried, true, and federally accepted. Best for broad-panel detection and DOT compliance. 
• Oral Fluid: Quick, clean, and tamper resistant. Detects very recent use — considered ideal for post-incident and suspicion-based screens. 
• Hair: Tells a story over time (up to 90 days). Especially useful in pre-employment to filter out chronic users. 
• Blood: Gold standard for precision. Costly and invasive, but ideal for legal or post-accident verification. 
• Breath: Primarily used to detect alcohol (Part 4 of this blog series will discuss timing, detection windows, and compliance protocols). 

Accuracy and Defensibility: The Case for Doing It Right 

According to Quest Diagnostics’ 2024 Drug Testing Index, adulterated or substituted urine samples surged by more than 600% in 2023 — the highest rate in over three decades. 

Here’s how smart occupational health drug testing programs and employers stay protected: 

• Chain-of-custody protocols, from collection to lab, to preserve defensibility. 
• Lab-based confirmations to confirm rapid results. 
• Adulteration checks to catch synthetic urine or substitution attempts. 
• Medical Review Officers (MROs) to assess results, evaluate prescription medications that show up on a drug screen, and make a fitness-for-duty determination. 

The Prescription Problem: Legal Doesn’t Mean Safe 

Nearly 66% of U.S. adults take at least one prescription drug, based on Centers for Disease Control and Prevention data from the National Center for Health Statistics. This underscores the importance of occupational health drug testing programs. 

Opioids, medications to help relieve anxiety or depression, and sleep aids, taken as prescribed, can impact decision-making, coordination, and awareness among workers on the job. But a defensible process must be followed to reduce the temptation to make assumptions or take action before necessary evidence has been produced.   

Don’t fall victim to this real-world risk. When an employee using a legally prescribed medication is involved in an incident, you must follow specific steps to connect potential drug side effects with the incident by ensuring proper documentation and review. Otherwise, the liability risk falls on leadership. 

That’s where occupational health drug testing intersects with fitness-for-duty evaluations. WorkCare’s physicians can help you assess whether a worker can safely perform their essential job functions while on medication, ensuring that your response is medically sound and legally protected. 

How WorkCare Supports Smarter Occupational Health Drug Testing Programs 

Our end-to-end Workplace Drug + Alcohol Testing give employers the clarity and consistency you need to make informed decisions: 

• Nationwide network of secure testing sites 
• On-site drug testing services to minimize disruption 
• Help with policy development, program audits, and compliance 
• Medical Review Officer support and fitness-for-duty case review 
• Supervisor training to spot and document signs of impairment 

Focus less on process and more on prevention. 

Wrapping Up: Testing That Reinforces Safety Culture 

For your workforce, occupational health drug testing isn’t just about following the rules. It reflects your corporate values and commitment to occupational health, safety, and employee wellness. A comprehensive response to employee substance use risks will have a much greater impact than a safety poster on the wall ever will.  

Let WorkCare help you refine your approach and ensure your team has the right tools to protect and promote employee health – now and in the future. From policy to practice, we’ll make sure your testing strategy supports your people and your business. Contact us to get started.