The device called the Breeze, from Burlingame startup Breathometer, will also book a taxi if users drink over the legal limit.
The Breeze is a 2.25-inch-long, 1.88-inch-wide wireless device that weighs less than an ounce. It easily fits in a pocket or purse and pairs by Bluetooth to a smartphone app.
To measure blood-alcohol level, or BAC, users have to blow into the Breeze at least 20 minutes after their last drink to allow time for the alcohol to get into the bloodstream.
The app counts down the five seconds users need to blow into the Breeze, the San Francisco Chronicle reported. An electrochemical fuel cell sensor calculates the BAC and transmits it to the phone, which displays the reading instantly, along with how much time it will take for their body to process all the alcohol.
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