The Hidden Cost of Guessing: Why Employers Pay Twice When Workplace Drug Testing Can’t Tell Impairment from Presence
Cannabis policy has moved faster than cannabis science, and employers are the ones absorbing the gap. Most workplace drug tests still answer a question nobody actually asked: was THC present in this person’s system at some point in the last several days to several weeks? What employers actually need to know, especially before an employment decision, is whether the person was impaired at the time in question. Those are two different questions, and conflating them is proving expensive. Closing that gap, with workplace impairment testing rather than presence-only screening, is quickly becoming a legal necessity, not just an operational upgrade.
Why Cannabis Employment Case Law Hasn’t Caught Up
Cannabis employment litigation is still thin relative to the scale of workplace cannabis use, and that thinness cuts against employers rather than protecting them. Courts in states like Connecticut, Massachusetts, New York, Delaware, Arizona, and Minnesota have begun recognizing private rights of action for employees terminated or rejected from employment over a positive THC test when off-duty or medical use was involved. Noffsinger v. SSC Niantic Operating Co. is the clearest example: a Connecticut federal court held that rescinding a job offer over a positive pre-employment THC screen violated the state’s medical marijuana anti-discrimination statute, rejecting the employer’s argument that federal drug law preempted the claim. Because so few of these cases have gone to full verdict, employers have almost no body of precedent against which to calibrate their policies. Every new termination decision is effectively litigated on a blank slate, which raises both the likelihood of a costly misstep and the cost of defending against one.
California compounds this with AB 2188 and SB 700, which bar most employers from taking adverse action based solely on the detection of nonpsychoactive THC metabolites in urine or hair, a category of result that says nothing about same-day impairment. Employers who built policies around metabolite-based cutoffs now have a statutory gap between what their test measures and what the law allows them to act on. But even that does not go far enough: an oral fluid drug test certainly shows more recent use, but no drug test result or level proves impairment.
What Workplace THC Testing Uncertainty Actually Costs Employers
When an employer cannot show that a positive test reflects impairment rather than use from days earlier, every termination carries litigation exposure, and that exposure is not cheap:
Per-claim legal cost. Employment attorneys commonly cite a range of $50,000 to $250,000 in combined legal fees and settlement exposure for a single wrongful termination claim that proceeds through litigation, even before a verdict.
Settlement range. Average wrongful termination settlements fall between roughly $5,000 and $100,000, with EEOC data placing the more typical range at $5,000 to $80,000. Roughly one in ten cases that reach verdict produces an award of $1 million or more, a risk that is difficult to insure away entirely even with an EPLI policy.
Indirect costs. Beyond the check written to plaintiff or counsel, employers absorb discovery costs, management time, reputational exposure, and the cost of replacing an employee who may have been terminated without adequate cause. The National Safety Council estimates employers lose $81 billion annually to workplace substance impairment in productivity, absenteeism, and healthcare costs, a number that includes both genuine impairment employers failed to catch and positives that removed otherwise fit employees from the workforce.
The uncomfortable part is that this exposure exists on both sides of the same error. Employers who terminate based on a metabolite result risk a discrimination claim from an unimpaired employee. Employers who decline to test or to act at all risk the accident, injury, and workers’ compensation costs of an actually impaired employee. A testing regime that cannot distinguish the two is expensive no matter which way the employer leans.
Why Impairment Testing Changes the Economics of Workplace Drug Testing
Functional impairment assessment, tools that measure reaction time, eye tracking, cognitive processing, or motor coordination at the moment of testing, addresses the underlying defect in metabolite-based testing rather than just the symptom. Building a workplace impairment testing program around these tools shifts the legal question employers are answering, from “was THC present” to “was this person impaired right now.”
It gives employers a defensible, individualized basis for action. A termination grounded in a documented, same-day functional deficit is a fundamentally different legal position than one grounded in a positive THC test that could reflect use from two weeks prior. That distinction is precisely what statutes like AB 2188 are pushing employers toward, and it is the distinction that is hardest to argue against in front of a judge.
It reduces the volume and cost of testing. Organizations that layer impairment screening on top of, or in place of, drug testing can use lab-based confirmation testing for cases where an impairment screen actually flags a concern, rather than testing on a fixed schedule regardless of need. Conventional lab-based drug tests run $30 to over $100 per test depending on panel and method, and that figure does not include the indirect costs many employers absorb: transporting employees to an offsite collection site, sitting a worker on the sidelines pending lab confirmation, and the administrative time of managing the process. Impairment screening tools are frequently priced per employee or per subscription rather than per incident, allowing unlimited testing at no marginal cost per test, which changes the cost curve entirely at scale. And with cannabis legalization limiting pre-employment screening, low-cost impairment testing just makes sense.
It supports testing employers currently cannot afford to do. Pre-shift or post-break impairment checks are operationally and financially impractical with drug and alcohol testing but straightforward with a rapid functional assessment, closing a real-time safety gap that metabolite testing was never built to fill.
The Bottom Line for Employers
The absence of settled case law is not neutral ground for employers. It is a standing invitation to litigate, and the underlying reason is a measurement problem: presence is not impairment, and until an employer’s testing program can tell the difference, every adverse action carries avoidable legal risk. Impairment identification technology, and a workplace impairment testing program built around it, does not eliminate that risk, but it replaces a guess with a documented, defensible, individualized finding, which is exactly what both the courts and the statutes are beginning to require.
When a Termination Decision Ends Up in Court
Every organization eventually faces a case where a positive THC test and a termination decision collide with a lawsuit. When that happens, the strength of your position depends on whether your testing program and your documentation can withstand scrutiny.
Capwell Consulting Group’s Drug Testing Expert Witness Services give attorneys and employers an independent, scientifically grounded review of drug and alcohol testing programs, from specimen collection and chain-of-custody to lab methodology, cutoffs, and impairment interpretation. Nina M. French brings more than 30 years of toxicology, testing, and regulatory experience to expert reports, depositions, and courtroom testimony that hold up under cross-examination.
If your case relies on what a drug test result does (and doesn’t) prove, contact Capwell Consulting Group for a free case assessment.
About The Author
Nina M. French is a nationally recognized authority in drug and alcohol testing, cannabis science, impairment assessment, and regulatory compliance. She brings more than 30 years of industry leadership to her role as a Drug & Alcohol Testing and Impairment Expert with Capwell Consulting Group, where she leads the firm’s drug testing, impairment, and expert witness services.
About Capwell Consulting Group
Capwell Consulting Group is a nationally recognized litigation support and risk mitigation consulting firm specializing in highly regulated industries. Our firm provides industry-leading guidance, research, reporting, and expert witness testimony for legal proceedings involving employment screening & negligent hiring, FCRA litigation, drug & alcohol testing, and medical device quality and regulatory compliance matters. With over three decades of industry experience, Capwell Consulting Group is a trusted advisor to employers, attorneys, and consumers around the globe.
The information published within is provided for educational purposes only. The information is not intended to or constitute legal advice; instead, all information, content, and materials are published for general informational purposes only and not considered the views of a particular expert or consultant of Capwell Consulting Group, LLC. © 2026