NIST Makes First Detection of Cannabis in Breath From Edibles
Summary
Researchers at the National Institute of Standards and Technology (NIST), working with the University of Colorado Anschutz Medical Campus, recorded the first measurements of cannabinoids in breath after participants ingested cannabis-infused edibles. In a study of 29 volunteers who each consumed a gummy (5–100 mg THC), breath samples taken before ingestion and at roughly hourly intervals for three hours showed that 19 participants had significant increases in THC in breath following ingestion. Some participants showed a peak then decline within that window; others showed no increase or only decreases, and many had detectable THC before the study began due to slow cannabinoid clearance from the body.
The findings demonstrate that THC from edibles can be exhaled and detectable in breath, not just a residue from smoked cannabis, and that edible-derived THC may take longer to appear in breath. The work is an initial step toward reliable breath-based measurements for cannabis use, though standards and further toxicology work are still needed to link breath levels to impairment.
Key Points
- This is the first reported detection of THC in breath specifically after ingestion of cannabis edibles.
- Study involved 29 participants consuming gummies with 5–100 mg THC; breath samples were taken prior to ingestion and about hourly for three hours.
- 19 participants showed significant post-ingestion increases in breath THC; four showed no change and six showed decreases.
- THC was often present in breath before ingestion because cannabinoids clear slowly from the body, complicating single-sample interpretation.
- Edible THC can travel through the digestive system and be exhaled via the lungs; this challenges the idea that breath THC only comes from inhaled smoke residue.
- Multiple breath measurements over time may be needed for reliable detection of recent use; standard reference methods and device standards are still required.
- NIST is providing measurement science and will host a workshop with device developers, but is not developing a breathalyser device itself.
Why should I read this?
Quick version: this is the first real proof that eating cannabis can make THC show up in your breath — so if you care about road safety, testing tech or regulation, this changes the game. It says single breath checks won’t cut it and device makers and policymakers need to pay attention. We read the paper so you don’t have to — here are the bits that matter.
Context and Relevance
As cannabis use rises and outpaces alcohol in daily recreational use in the US, accurate ways to detect recent use are urgently needed for road safety and law enforcement. Unlike alcohol, THC is low-volatility and persists in the body, so breath detection is scientifically challenging. This NIST study advances understanding of how cannabinoids distribute and are exhaled after ingestion, informing future device development, standards-setting and toxicology studies that aim to link breath measurements to impairment. The results are relevant to regulators, device manufacturers, forensic toxicologists and road-safety researchers.
Author
Punchy take: NIST’s work is a genuine measurement milestone — not a finished breathalyser — but it gives device makers and policymakers a much clearer target. If you follow transport safety, forensic testing or breath-device tech, this paper deserves your attention.