The race toward the legalization of marijuana has set off another inevitable race: one to be first on the market with a handheld breathalyzer for pot. Reuters reports that Canadian company Cannabix will be the likely winner, given that it has a prototype device now being tested that can detect the presence of THC, the active ingredient in marijuana.

Another contender is Lifeloc, based in Colorado, whose chief executive cautions that the first versions of these devices will be relatively primitive. "I think the first breathalyzer on the market will be a simple 'yes' or 'no' for the presence of THC at the time of the test, and in that sense it won't provide a quantitative evidential measure," says Barry Knott.

In other words, the devices will be able to tell a police officer if you've got marijuana in your system, but not if you're actually impaired.

Medical Daily notes that "not enough is known yet about exactly how much is needed to impair driving abilities," and thus there's much confusion and inconsistency among states trying to impose such laws.

(Washington and Montana, for instance, have set a 5 nanograms/milliliter limit for drivers; in other states, the limit is zero.) Engadget echoes that, predicting that "until both the science and policy surrounding cannabis advance beyond their present states, don't expect these devices to be entered into evidence in your DUI case anytime soon." Still, the market is clearly there: Lifeloc, for example, thinks it will be able to sell its first models for about $3,000, about 10 times the price of its alcohol breathalyzers.

The companies declined to say when their products might be ready for market. (Also, it seems that marijuana can help heal broken bones.)

This article originally appeared on Newser: Coming Soon: Breathalyzer for Pot

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