FDA Weighs Petition On ‘Significant Harm’ Of Marijuana Hair Testing Device’s Positive Results From Secondhand Smoke
Marijuana hair testing device faces FDA scrutiny over secondhand smoke risks. Picture a break room at 3 a.m., stale coffee, uniforms creased by a long shift, and a plastic envelope of hair clippings masquerading as truth. That’s the scene the FDA is stepping into as it considers a citizen petition arguing that a widely used marijuana hair testing device may be doing quiet, serious damage—confusing mere exposure with actual use and turning livelihoods into collateral. The petition, filed by Harmed Americans for Reform in Medical-Device Safety (HARMS), says the Psychemedics Corporation’s FDA-cleared device is labeled in a way that suggests it identifies cannabis use, when in fact it detects cannabinoid metabolites that can lodge in hair from secondhand smoke. In the rough-and-tumble world of cannabis drug testing and employment screening, that distinction isn’t academic; it’s the difference between a paycheck and a pink slip.
What the FDA is weighing
Hair testing is seductively simple: clip, wash, analyze, pronounce a verdict. But chemistry is messy, and the body is a stubborn narrator. Metabolites like THC-COOH can be detectable for months in hair, introduced not only by intentional consumption but also by “external contamination”—ambient smoke floating through a room, a party you didn’t partake in, a neighbor’s porch session on a windy night. HARMS is asking the agency to order clearer labeling so no one mistakes the presence of metabolites for proof of marijuana use. They want an explicit disclaimer that the device cannot confirm use, only metabolite detection, and even suggest the technical wording for the instructions—down to the calibrator threshold of 10 pg per 10 mg of hair. In regulator-speak, that’s an attempt to draw a thick, dark line between detection and accusation. The FDA has acknowledged receipt of the petition, which is publicly posted on regulations.gov for the kind of daylight that forces precision and accountability. You can examine the filing here: FDA-2025-P-5438. As HARMS frames it, hair testing can detect cannabinoids, but it cannot definitively confirm marijuana use because external contamination is always possible
—especially with variability across hair types, treatments, and growth rates.
The human cost of a lab result
This is not a sterile lab debate. It’s about real people being labeled as users and disciplined—or fired—because a test marketed for employment and law enforcement settings implies more certainty than the science can deliver. A false positive in this context isn’t an abstraction; it’s a mortgage payment that doesn’t get made, a career tracking sideways, medical care altered because a chart now whispers a story it can’t back up. As David Simon of HARMS puts it, the labeling and instructions for use are the device—the moral of the story bound to the instrument. If the manual suggests it can identify marijuana use when, at best, it flags metabolites with multiple possible origins, then the tool invites misuse. And let’s be honest: in workplaces and police departments under pressure to make quick calls, caveats get lost. Overstated certainty is a hell of a drug.
Science, policy, and the fog of war
We’ve layered a century of drug-war reflexes onto a fast-evolving cannabis landscape, and the result is a fog thicker than cold gravy. Even outside hair testing, experts continue to question whether THC levels track reliably with impairment, and whether per se limits in driving laws map onto real-world safety. The upshot: cannabis science is still negotiating with the demands of courts, HR departments, and insurance adjusters. Meanwhile, other fronts in the culture clash rage. As Congress toys with rules for THC-infused beverages and hemp-derived drinks, the alcohol lobby has started flexing: see this pulse check on how Alcohol companies lobby Congress on cannabis drinks (Newsletter: October 22, 2025), and the broader push as the Alcohol Industry Steps Up Lobbying On Hemp Drinks As Congress Debates THC Ban. At the state level, voters approve reform and legislatures sometimes tug the reins, like in Ohio where Ohio Lawmakers Advance Bill To Scale Back Voter-Approved Marijuana Law And Impose Hemp Regulations. And on the innovation beat, scientists are inventing ways around the plant entirely—yes, really—such as the report that Scientists Develop New Class Of CBD Using A Common Kitchen Spice—Not Cannabis. All of it feeds back into the testing dilemma: if policy, products, and pathways to cannabinoids are proliferating, then a blunt instrument that can’t distinguish context invites collateral damage.
What clarity looks like now
Clear labeling won’t solve every fight over cannabis drug testing, but it’s a start. The petition’s ask is modest and technical: direct the manufacturer to stop implying that a metabolite-positive hair sample proves marijuana use, and replace it with precise, sober language that tells employers and law enforcement what the device can and can’t do. If that sounds small, it isn’t. In a system that often defaults to punishment first and questions later, guardrails save careers and protect patients from inappropriate care. Employers can do their part, too—use multiple measures, consider context, and avoid substituting forensic theater for fact. The FDA has an opportunity here to make the rules of engagement clearer, to let science speak without bravado, and to keep a lab result from becoming a scarlet letter. And if you’re navigating this shifting terrain yourself and prefer your cannabis experience straight from the source rather than from the rumor mill of a lab report, explore our curated selection here: https://thcaorder.com/shop/.
