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Researchers Say New Breathalyzer Can Measure Pot Intoxication

marijuana breathalyzer

It took decades for the alcohol breathalyzer to gradually gain acceptance. There was an ongoing debate from the 1930s through the 1960s among lawmakers, police, scientists, and the public on the accuracy of the numbers given by the device, the correct legal limit for drivers, and the reliability of a machine over the testimony of a cop.

In today’s times, there has been a return of the same debate, with cannabis being the substance in question.

In 33 states and the District of Columbia, marijuana has been legalized in some form. Devices similar to the breathalyzer, which could potentially help law enforcement, have started to appear in various phases of development. But according to scientists and legal experts, there is a long road ahead before those devices will be able to detect a motorist’s impairment.

New Devices to Detect THC in the Breath

In a recent announcement, a University of Pittsburgh team of researchers presented the latest device to detect THC, or delta-9-tetrahydrocannabinol, the primary psychoactive component in marijuana, in the breath. 

Under the leadership of Alexander Star, the university’s Star Lab started developing the box-shaped apparatus in 2016. At this time, there was a strong wave of cannabis legalization throughout the country. To create the prototype, Star, a professor of chemistry, joined forces with Ervin Sejdic, an electrical and computer engineering professor who is also at the university.

In this device, carbon nanotubes, which are 1/100,000 the size of human hair, are used to identify THC in the breath, even in the presence of other substances, such as alcohol. The molecules contained in THC bind to the tubes’ surfaces, changing their electrical properties.

A news release from the Swanson School of Engineering at the university elaborates that nanotechnology sensors can identify THC at levels that are comparable to or better than mass spectrometry, a gold standard in THC detection.

The device is now almost ready for large-scale production.

In an interview with Jeremy Hobson from Here & Now, Star said that the device itself would be ready in a few months if they find an appropriate industrial partner. He says that the remaining steps include prototype testing and correlating the output of the device to the level of impairment of the driver.

The “Blood to Breath” Ratio

Impairment due to alcohol is measured by the level of alcohol in a person’s blood. A Breathalyzer can help determine this using the “blood to breath,” or “partition” ratio.

Denver-based lawyer Chris Halsor, who specializes in matters involving legal cannabis, believes that in terms of marijuana breath tests, that is the most vital question right now.

Does a ratio exist that links the level of THC in a person’s breath to the amount of THC in their blood? Can this tell us precisely how stoned this person is? According to Sejdic, the answer is no, as the correlation is lacking from a scientific perspective.

Sejdic and Star have determined how to set a limit on their device to detect only a specific level of THC, which they believe will avoid flagging marijuana use from several days earlier. However, in the absence of an in-depth understanding between that amount and the level of impairment of the driver, the device may not be especially useful to cops.

How much of Cannabis in the Blood is Safe for Driving?

Apart from this issue, there is the legal aspect of what level of cannabis intoxication is safe to be behind the wheel. It can be hard to determine this amount. The courts in the US took several decades to decide on the present blood alcohol concentration limit of 0.08 percent.

Haslor has spent years teaching law enforcement about cannabis DUIs and says that some cops that he works with a reluctant to buy into the use of such devices. They fear that a police officer with insufficient training might use one as a shortcut rather than assessing a person and evaluating how there are functioning physically, cognitively, and mentally. 

He proposes a more practical approach, i.e., training cops to understand and identify pot usage without the use of breath or blood tests. Haslor believes in the possibility of having a great device to detect marijuana usage in the future, but for now, he has his reservations.

He is particularly concerned about devices not undergoing human testing due to federal laws surrounding marijuana.

This is a challenge that Star and Sejdic understand well. They reveal that it took six months just to commence their research as they had to obtain the permission of the Drug Enforcement Administration to be able to work with THC.

Sejdic believes that the issue is both ethical and legal. Cannabis is still a Schedule I drug, which makes it challenging to conduct any research involving this substance.

Haslor says that the breakthrough that would make this type of device practical might take place in Canada. The nation decided to legalize marijuana last year. It has now opened its doors to allow cannabis research to take place unencumbered. 

The researchers at the University of Pittsburgh hope that the United States might get the ball rolling as well.

Consult with an Experienced DUI Attorney Today

If you face a DUI charge, it is a good idea to work with a qualified DUI lawyer to ensure that you receive the minimum penalty possible. At the law offices of Ron Aslam, an experienced attorney can review your case and recommend the best legal course for the situation. Call (502) 581-1676 today or message us online for a free consultation.