Buy your own Breathalyzer

Keeping a breath alcohol tester in your car may sound like a smart idea when it's party night, but there are caveats.

By MSN Money Partner Jan 11, 2013 5:40PM

This post comes from Mark Vallet at partner site logoAre you OK to drive, or should you call a cab?


Drunken driver © rolfo, Flickr, Getty ImagesIf you make the wrong decision, you may end up in jail or worse. You will meet lawyers. You will wear out your checkbook. And you will flinch when the car insurance bill comes.


Or you could buy your own personal alcohol breath tester and blow.


Devices cost $3 to $300, and their accuracy varies almost as much. The wrong device is worse than useless if it puts a drunk behind the wheel.


Yet more and more people are slipping one into their glove compartments. According to Wintergreen Research, sales of breath alcohol analyzers hit $284.6 million in 2011, and they forecast that number will climb to $3.2 billion by 2018 as prices fall and accuracy improves. In fact, French law already requires that all drivers carry one.


A guide, not a guarantee

In the end, the only number that counts is the one on the police officer's device.


A first-time DUI can cost thousands in court fees and will easily double your insurance rates, says Penny Gusner, a consumer analyst with A second DUI may send your rates up 300% -- when you get your license back.


A final caveat: Blowing a number under the legal limit is not a free pass to drive. Impairment is more than just a number, and it is possible to be under the legal limit and still be arrested.


According to Gusner, the insurance premium jump for impaired driving is very similar to one for a DUI conviction.


"I would give myself a wide, wide margin of error," Gusner says.


A long way from the Drunkometer

While alcohol intoxication is defined as a blood alcohol concentration (BAC), testing blood is just not feasible when you are out on the town.


The modern, portable method of measuring breath alcohol concentration emerged in 1954, when Robert F. Borkenstein, a forensic scientist with the Indiana State Police, perfected the Drunkometer.


Breath analyzers work because alcohol shows up in exhalations. It is not digested, or even chemically changed in the bloodstream. While the police use desktop spectrophotometer units at the station to collect a reading that can be introduced in court, they use personal breath testers out on the road.

If you're shopping for personal use, four types are available:

  • Fuel cell. Allen D. Porter, the president of, says fuel cell breath alcohol analyzers closely mirror what law enforcement officers use in the field. The fuel cell produces an electrical charge when it interacts with alcohol that can be precisely measured and translated into a BAC reading. Prices start around $100, and high-end models can run more than $300. 
  • Semiconductors. Breath testers that use a semiconductor as a sensor range from strictly novelty items to models that rival fuel cells in accuracy. The type of semiconductor material is what separates the toys from the real thing, Porter says. Silicon oxide-based models are more expensive, ranging from about $85 to $250, but are considered more accurate.
  • Crystals. These are single-use disposable units. You simply squeeze the unit to activate it and then blow into it. The crystals will change color if you are blowing over a set BAC level. According to Porter, they are popular with the military and are fairly accurate. These disposable units are priced about $3 but can be cheaper in bulk.
  • Key chains and phone apps. Breath testers that cost less than $50, come on a keychain or connect to your iPhone are best considered novelties for entertainment purposes. (Some apps, for example, track your eye movements.)


Personal breath testers are available at a variety of stores. Amazon carries a wide selection, as do Best Buy, Target and even Wal-Mart. Specialty websites such as offer every brand under the sun.


Finding the right breath alcohol tester

Regardless of the type you choose, there are a few things you should look for in a personal breath alcohol analyzer:

  • FDA certification. The Food and Drug Administration considers breath testers to be medical devices and certifies them as safe after testing. Any device that lacks FDA certification is sure to be inaccurate.
  • A mouthpiece. Accurate analyzers have a mouthpiece that is attached directly to the device. This ensures that the sample is not contaminated by smoke or other pollutants in the air. The mouthpiece should be removable and washable. Most models come with extra mouthpieces.
  • Accuracy rating. An analysis is useful only if it is accurate. The highest accuracy ratings for testers run around +/-0.005. Most experts recommend a device with an accuracy rating of at least +/-.01.
  • Calibration. An accurate breath analyzer will require calibration at some point in its lifetime, with the exception of disposable units. If it doesn't require recalibration by its manufacturer, it may not be accurate enough to rely on. Fees range from $20 to $50. Currently there are models on the market that use a replaceable sensor module, eliminating the need for factory calibration.

Experts say you should wait at least 20 minutes from your last drink or cigarette to check your BAC. This will give the most accurate rating.


They also advise some practice -- in the security of your own home -- to make sure you know how to use the device before trusting it after drinking.


A possible consequence for poor accuracy? A highly accurate, state-sponsored model you'll have to use every time you turn the key.


More from and MSN Money:



Jan 11, 2013 11:42PM
You can use it in a bar and ask a woman to blow into it.  When she shows drunk, you can take her home. 
Jan 11, 2013 7:18PM
I think most people who drink know if they're over the limit.  Why spend big bucks just to confirm what you already know.  Just don't drink and drive.  Plus the law can make it anything they want.  Be safe!
Jan 11, 2013 11:47PM
There used to be these devices back in the 70's in bars that told you what your B.A.C. was turned out to be a bad idea because of competitions that arose to see who could score the highest
Jan 14, 2013 10:06AM

Why aren't breathalyzers required, standard equipment in vehicles? Because the insurance and legal systems use DUI as a gigantic money making ponzi scheme. Ten thousand deaths per year, yet not a word published on how little alcohol it takes to reach the 0.08 limit (of course a lot depends on your weight, how quick you drink it, etc.) but not a word. Seems that should be published on a biannual basis. In 2014 all new cars will have a black box under the seat so the insurance companies can watch your driving habits. The information is suppose to be confidential of course but if you believe that one I have a bridge you might want to buy, but a breathalyzer, no way. I wonder how many billions the scheme takes in? So TV's and monitors with cameras and microphones in them, isn't that an unconstitutional invasion of privacy? But have to blow before it will start? Not a chance.



Sep 25, 2013 2:50PM
Depending on your needs, portable breathalyzers can be inexpensive or run into the hundreds of dollars.  Most folks simply want something that'll give them an indication that they should not drive after a night out.  I've seen people simply want a cheap device that'll prove a point to their friend/spouse, etc. that shows what their BAC is.  I review portable breathalyzers extensively at and hope you join my deep dive into how a PB can change your life.
Oct 20, 2013 10:57AM
What's great about today's portable breathalyzers is that they're getting less expensive and more accurate.  They're also getting easier to use (for example, there's on that interfaces with your iPhone).  My family has benefited from using a portable breathalyzer that we've even started our own company, <a href="">Breathalyzer City</a>. 

Get yourself a portable breathalyzer and save a life. 
Jan 14, 2013 11:31AM
You don't need a breathalyzer.  If you drink at all don't drive.  No margin for error that way.
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