“Cannabis sativa” by Manuel is licensed under CC BY 2.0

Cannabis Breathalyzer Still In Its Infancy

MedicalResearch.com Interview with:

Tara M Lovestead, PhD, (She/her/hers)Group Leader | Fluid Characterization Group Applied Chemicals and Materials Division National Institute of Standards and Technology Gaithersburg, MD 

Dr. Lovestead


Tara M Lovestead, PhD, (She/her/hers)
Group Leader | Fluid Characterization Group
Applied Chemicals and Materials Division
National Institute of Standards and Technology
Gaithersburg, MD


MedicalResearch.com: What is the background for this study?

Response: In 2012, when cannabis was decriminalized for adult recreational and medical use in Colorado, I started thinking about how a cannabis breathalyzer could work. I knew that an alcohol breathalyzer model would be pursued for a field sobriety test, but also knew that THC, the main psychoactive compound in cannabis, was a completely different animal, chemically speaking, than ethanol, the intoxicant in alcohol. I began by measuring the vapor pressure of THC and determined that it is a million times less volatile than ethanol. This is why the main strategy for measuring THC in breath is based on collecting breath aerosols with filters (ethanol is measured as a vapor in breath and does not need to be “collected”). My colleague, Dr. Kavita Jeerage and I began working together to design a study using a simple device that samples breath aerosols that hadn’t been used before. We designed this as a small study to piggyback on a larger study with our collaborator Prof. Cinnamon Bidwell at the University of Colorado, Boulder. Bidwell’s experience studying the effects of legal market cannabis product use on psychology and behavior was leveraged to launch the pilot study.

MedicalResearch.com: What are the main findings?

medical-marijuana-cannabisResponse:  The main finding is that it is really hard to sample such small quantities of THC and that small differences in participant behavior or timing could have impacted the results. We collected nanograms of THC after sampling 12 breaths, about a million times less than the amount of ethanol you would get from one breath from an intoxicated individual. The technology is there to measure this small amount of THC – however, the standardization isn’t. There is a huge spread in the data from our study and the six other pilot studies in the peer reviewed literature. Standard materials, standardized sampling protocols and unbiased evaluation of cannabis breathalyzer devices need to be in place. We also concluded that more than one sample might be necessary to differentiate recent use vs. past use. 

MedicalResearch.com: What should readers take away from your report?

Response: Development of a cannabis breathalyzer is very desirable for workplace safety and law enforcement, yet there is much more research that needs to be done to standardize and implement such a device. The alcohol breathalyzer is a more straightforward device to design and deploy; the cannabis breathalyzer is in its infancy by comparison. That doesn’t mean it isn’t possible, it just means that we will be working on the science of cannabis breathalyzer measurements for many years.

The NIST team has two ongoing studies right now. One study is investigating another sampling device and includes participants that smoke or vape. Another study with the same device will have a larger participant group and will include multiple study sessions for each participant. 

MedicalResearch.com: What recommendations do you have for future research as a results of this study?

Response: Studying other forms of consumption is important. Sampling devices are important too. Studying different modes of cannabis use and different breath sampling devices will enable us to determine how THC and other cannabis compounds enter the breath and are carried in breath. Laboratory studies with standardized methods and materials to compare device performance are also necessary.

Disclosures: The research is funded by an award from the National Institute of Justice (NIJ)  in the Department of Justice (DOJ): Chemical Foundations of a Cannabis Breathalyzer. PIs: Jeerage, Widegren, Lovestead, Award # DOJ-NIJ-19-RO-0008, Sept 2019-Dec 2022.


K.M. Jeerage, C.N. Beuning, A. Friss, C. Bidwell and T.M. Lovestead. THC in breath aerosols collected with an impaction filter device before and after legal-market product inhalation — a pilot study. Journal of Breath Research. Published online May 22, 2023. DOI: 10.1088/1752-7163/acd410


The information on MedicalResearch.com is provided for educational purposes only, and is in no way intended to diagnose, cure, or treat any medical or other condition. Always seek the advice of your physician or other qualified health and ask your doctor any questions you may have regarding a medical condition. In addition to all other limitations and disclaimers in this agreement, service provider and its third party providers disclaim any liability or loss in connection with the content provided on this website.



Last Updated on May 24, 2023 by Marie Benz