Is there a breathalyzer for marijuana?

The breathalyzer has become the go-to piece of evidence in DUI cases across the country, but it only works for alcohol. Is there some way that police can determine whether a person is “too stoned to drive” with a roadside breath test or a machine like the Datamaster?

Not yet.

There is a breathalyzer for marijuana in development that may become available for use in the next few years. But, when a breathalyzer for marijuana is released and placed in the hands of law enforcement, can it really detect whether a person is too stoned to drive?

Would a breathalyzer for marijuana detect the levels of THC in a person’s system? How long it has been since a person smoked marijuana? Could it really determine to what extent a person’s faculties to drive have been impaired?

Is There a Breathalyzer for Marijuana?

The new “holy grail” for DUI enforcement is a “breathalyzer for marijuana.” Of course, the assumption that a marijuana breathalyzer would work is based on several other assumptions – that people who smoke even a small amount of marijuana are too impaired to drive, for example…

Is There a Breathalyzer for Marijuana in Development?

According to the Sacramento Bee, there are several marijuana breathalyzers in development that could be released as soon as next year:

Drivers suspected of being high on pot may soon face the same type of roadside breath test cops use to catch drunken drivers, as several firms prepare new devices for the street.

Hound Labs of Oakland expects to have a marijuana breathalyzer ready by the second half of 2020, according to Mike Lynn, a medical doctor and co-founder of Hound Labs. Another firm, SannTek of Canada, also is racing to have a product ready in that timeline.

But what exactly will marijuana breathalyzers tell police?

Can it tell police if a person is too impaired to drive safely, or will it just tell police whether a person has smoked marijuana regardless of the amount?

What Kind of Legal Challenges will Face a Breathalyzer for Marijuana?

For a police officer who believes any amount of alcohol is too much to drive – the type of law enforcement officer who will take a person to jail if they smell alcohol, and then claim the person was high on drugs when the breathalyzer says their BAC is under .08 – a marijuana breathalyzer that detects any amount of THC might seem good enough.

But the law does not say it is illegal to drive after drinking any amount of alcohol. SC DUI laws also do not say it is illegal to drive after smoking or ingesting any amount of THC…

Breathalyzers for Marijuana Probably Will Not Detect Levels of THC

Establishing that a person has THC in their system is not enough for a DUI conviction. Obviously, if a person smoked marijuana the week before or even the day before a traffic stop, they are not “under the influence.”

The marijuana breathalyzers that are currently in development claim that they will determine whether a person has smoked marijuana within three hours of taking the breath test – the time frame when a person is “most impaired:”

Hound Labs says its test will show whether a motorist smoked marijuana within a three-hour window before driving. That, Hound Labs’ Lynn asserted, is the time frame when drivers are most impaired. He cited statistics indicating that 14.8 million Americans have used marijuana within an hour of starting a car.

SannTek’s Noah Debrincat, a nanotechnology engineer from the University of Waterloo in Canada, said his device also can identify a driver who has gotten high within three hours of driving.

But is that good enough for a DUI conviction?

Just as a person can have a beer or a glass of wine or two before driving, a person can also smoke a joint before driving, depending on how strong the weed is and how big the joint was…

What Does the State Have to Prove in a DUI – Marijuana Case?

It is not against the law to drink and then drive in SC. It’s also not against the law to smoke a joint and then drive in SC. (Well, it is against the law to possess a joint in SC, but it’s not against the law to drive after smoking one…)

It is against the law to drive when you are intoxicated to the extent that it materially and substantially affects your ability to drive.

Whether the intoxicating substance is alcohol, marijuana, or cough syrup, the state must prove your level of intoxication. Their best evidence is usually the breathalyzer because the breathalyzer provides a measurement of just how much alcohol is in your system. Greater than .08 blood alcohol content = DUI per se under SC law.

What is the “threshold limit” for THC? There is none.

If police take a blood sample and it is tested in a lab, they can determine the levels of THC in a person’s system. Then a toxicologist can testify on behalf of the state (or the defense) as to the likely effect of a particular level of THC in a person’s system and how it would affect their driving ability.

As with alcohol, testimony that a person has THC in their system, or even that a person ingested THC within three hours of the test, is not enough to convict a person of DUI. DUI-marijuana cases rarely go to trial, because unless the state has 1) a blood sample or urinalysis, and 2) a toxicologist prepared to testify, they cannot prove DUI through chemical analysis.

Will Police Start Using Marijuana Breathalyzers?

I doubt police will use marijuana breathalyzers anytime soon. They will immediately be challenged in court and, if they cannot determine the level of THC in a person’s system, they should not be admissible at all.

It will have immediate applications in the workplace, however:

Lynn said he expects the Hound Labs device will also be used in the workplace, where employers can ensure that workers are not high on the job, and employees won’t face sanctions if they partied the day before.

Debrincat said there is demand for the breathalyzer in jobs like truck driving and construction, where workers are operating heavy machinery.

“I actually do see it as benefiting all parties” in the workplace, he said. Presently, most employers rely on urine tests, designed 30 years ago. Those tests can show that an employee smoked weed as much as a month ago, but don’t establish that they are high on a test day.

For purposes of a DUI arrest, it is irrelevant whether a person smoked marijuana three hours ago if the state cannot also establish the person’s level of intoxication.

In the workplace though, especially in weed-legal states, it may be effective in distinguishing whether a person smoked a bowl the night before or if the person smoke marijuana while they were on the clock or just before clocking in…

Marijuana Defense and DUI Lawyers in Charleston, SC

Grant B. Smaldone is a criminal defense trial lawyer in Charleston, SC who accepts both marijuana defense cases and DUI defense cases in the Eastern SC area.

If you have been charged with DUI in Charleston, SC or the surrounding area, call now at (843) 808-2100 or schedule a consultation through our website to talk to a Charleston, SC DUI defense lawyer today.