Author: Boulder Daily Camera
Police have measured alcohol intoxication through breath for decades.But for cannabis, it’s not so simple.The University of Colorado Boulder, in partnership with the National Institute of Standards and Technology, conducted a pilot study to develop reliable protocols for developing a cannabis breathalyzer.Some startup companies have already begun creating cannabis breathalyzers, but there’s no science-based guidance for how to make an accurate one.“As companies create different types of prototype devices … we would like to be in a position to verify that those devices are working as intended,” said Kavita Jeerage, materials research engineer at NIST.Although it seems like breathalyzer science should be a smooth transition from alcohol to cannabis, that’s not the case, CU Boulder Associate Professor Cinnamon Bidwell said.“Unfortunately, there’s still a lot of steps to be completed to understand whether it’s going to be possible to develop a cannabis breathalyzer,” Bidwell said.The University of Colorado Boulder mobile lab van was used to conduct a study on detecting cannabis in breath (Matthew Jonas/Staff Photographer)Measuring cannabis impairment through breath is more complicated compared to alcohol.Detecting ethanol in breath is a reliable measure of roadside alcohol intoxication, but measuring THC — the component of cannabis that has the strongest link to impairment — is much harder.The THC that sticks around in breath or blood is at minute levels compared to alcohol, Bidwell said, and it’s like searching for a needle in a haystack.NIST research has shown that people exhale 1 million times more ethanol in a single breath than the amount of THC cannabis users exhale in 12 breaths.Low levels of THC are hard to detect and there’s no standardized measure for a large or small amount of THC on the breath, Bidwell said.Additionally, cannabis is stored in fat and throughout the body and could remain in someone’s system for several weeks without use.To complicate matters more, some people routinely use cannabis for medical purposes.“I think it’s important to remember that we at NIST and everyone who is involved are trying to figure out what we can learn from breath measurements and how to best implement them in the field,” Jeerage said.“And, as a starting point, it may not be as sensitive as maybe the alcohol breathalyzer is today.”For the study, researchers collected breath samples from 18 volunteers. The volunteers were told to purchase a specific strain of cannabis flower containing 25% THC.The researchers instructed the participants to use the cannabis in their homes and come outside to participate in tests at a mobile van laboratory.This system was created because cannabis is illegal at the federal level and researchers are not allowed to handle or administer it.The interior of the University of Colorado Boulder mobile lab van is seen on Wednesday, Oct.25, 2023.(Matthew Jonas/Staff Photographer)The breath samples were then taken to NIST laboratories for testing, and the results varied.Eight participants showed the anticipated increase in THC after cannabis use.In three breath samples, THC was not detected at all. In several other samples, THC levels in breath were similar to or lower than baseline levels.While the results varied, Bidwell said they had strong data to show they did detect cannabis in breath.Bidwell said the next step is to conduct a larger study to learn more.The data allowed them to get funding for another study, which is beginning now and will include about 45 people instead of 18.In future research, the NIST team hopes to get a better understanding of the chemical properties of THC, experiment with other methods of detecting it in breath and develop standard reference materials that labs could use to calibrate their equipment.Bidwell said if a cannabis breathalyzer will be used in a public safety setting, it needs to be reliable.“The impact is to move us forward and try to have an objective measure of cannabis use that can be used roadside,” Bidwell said.Jeerage said her goal is to figure out what’s feasible and what they can learn from breath sampling, which can provide valuable information for law enforcement and people on the road.She said to remember the alcohol breathalyzer took decades to develop and that scientists are just at the beginning of researching the science behind one for cannabis.“It’s important for public confidence,” Jeerage said.“I think that a technology that is potentially going to be deployed by employers or law enforcement needs to be based on sound science and that sound science can be important in building trust in the measurement.”
