Breakthrough: Detecting Cannabis in Breath After Edible Consumption

Recent research has demonstrated that cannabis can be detected in a person's breath following the intake of edible cannabis products, a significant development in drug testing and roadside sobriety assessments. As cannabis consumption becomes increasingly popular in the United States—surpassing alcohol in daily recreational use—law enforcement faces challenges in accurately determining recent use due to the lack of reliable roadside testing methods. Unlike alcohol, which can be quickly measured through breathalyzer tests, THC, the psychoactive component of cannabis, presents a complicated detection issue because of its low volatility and presence in small concentrations.

A groundbreaking study published in the Journal of Analytical Toxicology highlights the first successful measurement of cannabinoids in breath after ingestion of cannabis-infused edibles. Led by researchers at the National Institute of Standards and Technology (NIST), the study involved 29 participants who brought in gummies containing THC doses ranging from 5 to 100 milligrams. The researchers collected baseline breath samples before ingestion and continued to analyze samples every hour over a three-hour period.

Results showed that THC could be detected in most participants' breath even before edible consumption, indicating slow elimination from the body. After ingestion, 19 participants exhibited notable increases in THC levels in their breath, peaking within the observation period and then gradually declining. Interestingly, some participants showed no change or even a decrease, which could be due to measurement timing or individual metabolic differences.

This study confirms that THC and other cannabinoids do not solely originate from smoked cannabis but can also enter the lungs after ingestion of edibles, taking time to manifest in breath. This finding challenges previous assumptions that detectable THC in breath was only from recent smoking. Since THC can remain in the system for hours or even weeks, a single breath test cannot reliably determine recent use or impairment.

The research involved observing participants who consumed gummies with varying THC concentrations and measuring cannabinoid levels periodically. The results demonstrated that edible cannabis could make its way into breath samples, offering new avenues for developing roadside testing devices. However, the low volatility of THC and its presence in minute amounts make creating an accurate, easy-to-use breathalyzer a complex task.

While NIST is not developing a breathalyzer, its role is to establish standards to ensure measurement accuracy and reliability. Future research aims to explore timing of THC appearance in breath and potential levels linked to impairment, similar to alcohol testing. A workshop scheduled for September will facilitate collaboration among device developers to establish measurement standards.

This research marks a significant step toward real-time, non-invasive detection of cannabis use, regardless of consumption method, paving the way for improved law enforcement tools and safety measures. Still, the interpretation of such data will require further understanding of how these measurements correlate with impairment, a crucial aspect being addressed by toxicologists and related experts.

Source: https://medicalxpress.com/news/2025-07-cannabis-edibles.html