The legalization of marijuana in several states in recent years has fueled concern over drugged driving — and not just among law enforcement officials who want to prevent it. Pot users are also concerned that without a way to measure if a person is high — current tests can only determine whether the person has recently used the drug — they could unfairly face consequences for driving under the influence.
A California company now says it has a solution.
Hound Labs Inc. is announcing Wednesday the development of a new handheld marijuana breath test, analogous to the Breathalyzer device that measures alcohol levels. The company says the product will for the first time allow for detection of the level of THC, the chemical responsible for most of marijuana’s psychological effects, in a person’s system from a breath test.
“The issue was really all-around measurement,” said Hound Labs CEO Mike Lynn. “We need a way to not only test ‘yes’ or ‘no’ for the presence of marijuana, but to actually measure and correlate THC levels with impairment, like we have done for alcohol.”
Other companies have touted the ability to detect marijuana through the breath in products currently in testing, but Mr. Lynn says his product will be the first to give precise measurements in picograms — measurements of one trillionth of a gram — that can be used to determine a person’s current level of intoxication from smoking marijuana.
Hound Labs plans to begin clinical trials of its breath-testing device in conjunction with the University of California, San Francisco, and San Francisco General Hospital early next year. The technology has been in development for two years, and while Mr. Lynn said he doesn’t plan to make any recommendations as to what levels of THC should be considered legally intoxicated, he hopes that his product will be able to serve as a tool for lawmakers looking to devise those limits.
“We are not going to be the ones to create the standard, we would leave that up to research groups,” he said. “For alcohol it took some time to develop the impairment standards. I’m sure it will take some time to develop the THC standards.”
One downside to the test, however, is its inability to detect THC intoxication if a person has ingested marijuana edibles — a wide array of products ranging from the standard marijuana-infused brownies and candy to tea. Mr. Lynn said that he’s trying to develop technology that could detect edible marijuana intoxication as well.
Four states and the District of Columbia have legalized recreational marijuana use, with others like California adopting lenient medical marijuana laws that allow for widespread use of the drug.
But so far, only Colorado and Washington state have set a legal limit for intoxication from THC. Motorists in those states are considered to be driving under the influence — jokingly referred to as “driving while baked” — if 5 or more nanograms of THC are found in their blood. However, critics have countered that habitual marijuana users may build up a level of THC in their blood that stays above that level even if they have not recently used the drug and are not high while driving.
“We have individuals who have been using cannabis throughout the day for decades, and they say if you institute something like this, they won’t be able to drive anymore,” said Amanda Reiman, manager of marijuana law and policy for the Drug Policy Alliance.
But law enforcement officials continue to worry about the mix of pot and driving, fearing that widespread access to marijuana in states like Colorado could contribute to more traffic crashes.
The Colorado State Patrol reported in 2014 that, out of 5,546 citations for driving under the influence of drugs or alcohol, 674 — 12.2 percent — involved suspected use of marijuana either alone or in combination with other intoxicants. Marijuana was believed to be the only substance used by 354 of the people cited.
But others remain critical of the idea that marijuana use can even be measured in the same way as alcohol impairment.
“To date, no such data exist correlating THC/breath detection levels with behavioral impairment,” said Paul Armentano, deputy director for the National Organization for the Reform of Marijuana Laws. “In fact, no scientific study that I am aware of has even attempted to correlate the detection of THC in breath with actual behavioral or psychomotor impairment of any kind.”
Ms. Reiman said while inventors and entrepreneurs have focused on trying to develop a device similar to those used by police to detect alcohol, it may not be the best-suited device for determining whether a person is too impaired to drive.
“The research we see is there really isn’t a standard limit at which intoxication occurs,” she said.
Instead, Ms. Reiman pointed to several smartphone applications already available that individuals can use to test their own response times while under the influence. Identifying the same type of performance measures used in the apps and creating more reliable field sobriety tests based on some of those measurements might be more beneficial to law enforcement than waiting for a breath test that works, she said.