back to article 2014: El Reg booze lab proves Bluetooth breathalyzers are crap. 2017: US govt agrees

If you’re trusting a personal breathalyzer to protect you from a drunk driving conviction, think again, since the devices might not work as advertised. In the past few years, various companies have begun marketing personal breathalyzers that fit in your pocket and can report blood alcohol content (BAC) levels to a smartphone. …

  1. Your alien overlord - fear me
    Pint

    What about testing those disposable ones that you have to carry when driving in France?

    1. JetSetJim
      Pint

      This article from a couple of years ago says they're not that brilliant (one was crap) and laments the lack of regulations in this area. The best of the devices tested would falsely reassure a drunk that they were safe to drive approximately 1 in 20 times.

      More readable writeup here. Dunno which brands are on sale in France.

      Naturally the Alcosense website makes no mention of this research...

    2. agurney

      If my memory serves me correctly.. the French ones had to be from an approved manufacturer, sealed and in date. If you were stopped, the police would test you with your own kit, with presumably any indication of booze in the system resulting in a trip to the station for a test with an accurate machine. Potential nice little earner for the manufacturers involved, and savings for the Gendarmerie, but now there's no penalty for not carrying them.

  2. Anonymous Coward
    Facepalm

    What if people got arrested because of these devices ?

    If they thought it would be safe to get behind the wheel because the device said they would be ?

  3. Anonymous Coward
    Anonymous Coward

    "We chose to settle in order to focus on our mission,"

    LIAR

    1. Joel 1
      Trollface

      Re: "We chose to settle in order to focus on our mission,"

      I think you mean "alternative fact stater"

  4. Anonymous Coward
    Anonymous Coward

    I knew that too

    It's a very simple device to test. You will need a lot of booze and some breath.

  5. Adam 52 Silver badge

    Breath testing in general is quite variable. Standard practice, before all the cuts, was to send student Constables out to get pissed with a portable Police issue unit. Some would be over after 1 pint, some could be legless and still only blow a warning result.

    When the units came back for audit they were noticeably different to units used in the field - in real life results were clustered around no alcohol and well over, the student ones had a more even distribution (which you'd expect really, as you only ever test people whose driving is bad or who were being tested routinely).

  6. Ol'Peculier

    Best line in the article:

    "If you’re concerned that you’ve had too much to drink, it’s probably a sign that you have, and a taxi is in order."

    Amen to that.

    1. Anonymous Coward
      Anonymous Coward

      Re: Best line in the article:

      Agreed, but what about the next day? If I leave my car in a pub carpark, can I retrieve it at noon the next day? 2pm? 5pm?

      I've looked into this before, but didn't want to risk my license on a piece of cheap crap that might tell me I'm fine when I'm not.

      Obviously common sense prevails - if you feel fine you probably are but without something to confirm it reliably, you're taking a risk.

      1. Anonymous Coward
        Anonymous Coward

        Re: Best line in the article:

        I unfortunately had the misfortune to think I was OK to move my car after 2 pints. I wasn't. After leaving the cop shop I went out to try and rid a nightclub of it's entire back row of spirits.

        Next morning, when I went to pick up my car keys I was still over the limit. About lunchtime I tried again and was only just under the limit. Next day driving is not worth it if you've had more than "a few" the night before.

    2. Anonymous Coward
      Anonymous Coward

      Re: Best line in the article:

      I think it's the opposite; it's when I think that I can drive that I have had too much to drink!

      (full disclosure: I can not drive)

    3. Anonymous Coward
      Anonymous Coward

      Don't use it that way

      If you have any question that you might be over the limit, you shouldn't drive. If I have any intention or concern of getting near the limit, I don't have my car so its not an issue.

      I have a personal breathalyzer (not fancy bluetooth, it is self contained) I keep in my glovebox. Every time I am driving and have had anything to drink, even a single glass of wine at dinner, I do a quick check. I know what my reading "should" be based on what I've had over how many hours, and have found it matches up extremely well with this breathalyzer. I use it as a sanity check in case a drink was overpoured, or a craft beer had a higher BAC than I thought. If I'm over .05 (limit here is .08, I go by .05 to give the device a margin of error) then I'll go back inside for a bit and have a glass of water. It is rare because I'm pretty careful when I have my car but there have been a few times over the years I've found I was over .05 and waited.

      Posting anon because some people are so crazy on this issue they'd downvote anyone for daring to suggest it is OK to drive after even a single drink. Half of them think talking on the phone hands free while driving is fine though, even though studies show it is equivalent to driving after several drinks.

  7. horsham_sparky
    FAIL

    Too true

    I used to work for the company that designs and supplies breathalyers to police forces worldwide. The roadside units are based on fuel cells and are pretty expensive. Even then their accuracy isn't wonderful, but its good enough provided you're sufficiently under/over the limit.

    If there's any doubt, the analysers back at the station are based on infrared absorption, are are much more accurate (and correspondingly expensive).

    The commercial units are all based on semiconductor sensors, which are frankly Sh*~te.. don't both with them. As the article says, if you're feeling it, you're over the limit. Even if you're not feeling it, you may still be over the limit.. I speak from experience of testing these things (yes I was paid to do that, hahahahaha!) :-)

    And before you ask, you can't beat the analyser. Breath mints, mouthwash, penny on the tongue etc etc, all don't work. At best they add chemicals to your breath which the instrument is insensitive to. At worst, they will increase your reading (some older mouthwashes used to have alcohol in them). The best way to prevent alcohol being on your breath is avoid drinking alcoholic drinks... :-)

    1. Kane
      Boffin

      Re: Too true

      The best way to prevent alcohol being on your breath is avoid drinking alcoholic drinks

      Right, straight onto the intravenous drip then!

      1. horsham_sparky
        Devil

        Re: Too true

        Best check yourself into hospital when you try that one.. :-)

        Now IV caffeine.. that would be so much better than carrying a coffee cup around all day..

        1. Captain DaFt

          Re: Too true

          "Now IV caffeine.. that would be so much better than carrying a coffee cup around all day.."

          Ever try caffeine patches?

      2. Anonymous Coward
        Anonymous Coward

        Re: Too true

        Right, straight onto the intravenous drip then!

        Occured to me a long time ago that a syringe full of ethanol would be a great suicide method.

    2. tiggity Silver badge

      Re: Too true

      The best measure for accuracy is actually a blood sample, given that in UK, the limits are based on levels of alcohol in blood, and analysis of exhalations is always a poor substitute for what's actually running through your veins.

      1. horsham_sparky

        Re: Too true

        yup!

        But then you have to train the bobbies to take blood safely (and without turning your arm into a pin cushion if you've been a troublesome drunk), or taking to you a hospital to have it done (thereby using lots of scant NHS resources)

        Time is also a factor as your body is constantly breaking down the alcohol, so getting them to take a breath test at the roadside rather than a delayed blood sample will give a more accurate reading overall as to their state whilst they were driving.

        1. Robert Helpmann??
          Childcatcher

          Re: Too true

          The standard in at least parts of the US is to administer a field sobriety test and then confirm with a blood test at the station. I recently pulled grand jury duty and heard this litany over and over.

          1. allthecoolshortnamesweretaken

            Re: field sobriety test

            You should see the field sobriety test in Austria.

        2. MrDamage Silver badge

          Re: Too true

          > "But then you have to train the bobbies to take blood safely..."

          In Australia, once you've been pinged by the roadside unit, you're then taken back to the station for a secon reading from the bigger, more accurate unit, which is the one your charge is based on.

          After that reading you then have the option of having a blood test, which is conducted by a doctor/nurse who has to be called in to take the blood sample. Depending on locality, that can take anywhere from 15 minutes to a couple of hours.

          If you're only just over th limit (eg: 0.051), it may be worthwhile taking this option if it has been a while since your last drink, as there is a chance it will drop to below the limit by the time the medical professional arrives. If you've been boozing up until the point of jumping into the car, it's a gamble, as you could well go from low range to high range during the wait.

  8. toughluck

    *Sigh* Told you a million times, don't use *that* lab!

    According to the FTC, Breathometer sold more than $5m worth of its alcohol testing devices and claimed that they were “law-enforcement grade products” that were subject to “government lab-grade testing.”

    Of course they used lab tests. The problem is, they used the labs dedicated to testing blood samples collected from politicians and rich businessmen.

    1. Anonymous Coward
      Anonymous Coward

      Re: *Subject to testing"

      Anything can be subject to testing - the key thing is whether or not it's passed those tests.

      A noticeable example of this use of language is mouthwash. Most dentists will tell you it's a bit of a waste of money, and that you're better off just maintaining a good regime of brushing & flossing - I've never had a dentist of hygienist recommend mouthwash to me. Watch the adverts for mouthwash on TV, and they will very often carry the slogan "tested by dentists", but rarely "recommended by dentists"

      1. Duffy Moon

        Re: *Subject to testing"

        What I have read recently, by dental experts, is that mouthwash is effective (especially original Listerine) and thar flossing is pretty much a waste of time.

  9. Tikimon
    Angel

    Establishing a baseline - seemed to work OK

    Lots of charts and things available that show how much a person of given weight can drink and metabolize,etc. But like any other table based on an average of the general population, Your Results May Vary Amazingly. For instance, the BMI scale insists I'm badly overweight instead of the lean mountain biker I really am. So I got a BACTrack to establish an approximate baseline for myself. I did not trust my own assessment of my competence under the influence, even though I never or hardly felt the effects.

    I tested myself over several sessions of various drinking (wine tasting, night out, home) and at various time intervals per session. Over a period of weeks, I worked out some consistent numbers on how X number of drinks affects me over a given frequency of consumption, and after X hours have elapsed afterward. Where one test might be iffy, this gave me a decent data set to work with.

    I claim success. I now know to within a useful approximation how quickly I absorb and burn off alcohol. To what end? I do NOT try to game my BAC so I can be Barely-Legal and drive! However, I confirmed that my usual drinking habits (very careful) tended to give me a BAC of .003 or so. Which is worlds more specific and accurate for my body than a chart generalized from an unfit, overweight population.

    My point? BAC testers are not reliable enough for deciding at a given moment whether to drive or not. However, they can be useful to aggregate several readings and get a feel for ones personal relationship to alcohol.

    1. horsham_sparky
      Boffin

      Re: Establishing a baseline - seemed to work OK

      Frot the brief look at the BACTrack product, it seems a reasonably accurate fuel cell based unit.

      One of the things people forget with these units is that you need to wait for a period of time after you last consumed any food or drink (20minutes minimum) to get a true deep lung reading (i'm assuming the unit makes you breath out deeply before it takes a sample). The reason is that you will have alcohol in your stomach and vapour in your esophagus after you've drunk alcohol which skews the readings. Food tends to make you belch which gives the same problem.

      The other problem is the rate at which your body produces ADH (the enzyme that breaks down alcohol) varies significantly depending on your health, whether you drink on a regular basis, the time of day etc etc.

      Also the rate at which you absorb alchohol in your stomach varies on how much food you've eaten (i.e. empty stomach absorbs quickly so your blood alcohol level will spike high quickly, whereas with food in there it won't spike as quickly but hangs around longer)

      So I wouldn't put too much faith in past performance of your body as it will change with circumstances and time...

      sorry I'm a bit of booze-nerd, I had to know about this stuff when I was doing the electronics for the breathalysers :-p

  10. EddieD

    Life is easier up north

    Here in Scotland, we have a much simpler system - you don't drink at all if you're going to drive - and for best practice, not even the night before you're going to drive.

    The lower alcohol limit seems to have cut the number of folk who are measured over the limit.

    Which is good.

    1. Anonymous Coward
      Anonymous Coward

      Re: Life is easier up north

      And no-one stopped for a moment to think about the poor workers brewing Tennents at Wellpark whose very livelihoods are flung into jeopardy by this reckless disinclination to get smashed...

    2. horsham_sparky
      Trollface

      Re: Life is easier up north

      doesn't always work.. Sweden has one of the lowest limits in Europe (0.2g/l compared to 0.5 for scotland and 0.8 for the rest of the UK). And booze there is hideously expensive.. and yet they still have big problems problems with drink driving;

      https://ec.europa.eu/transport/road_safety/specialist/knowledge/alcohol/prevalence_amp_rate_of_alcohol_consumption/drinking_and_driving_en

      http://news.nationalpost.com/news/canada/canadas-drunk-driving-death-rate-worst-among-wealthy-countries-u-s-study-finds

      Go figure! :-p

    3. agurney

      Re: Life is easier up north

      "..The lower alcohol limit seems to have cut the number of folk who are measured over the limit."

      If Mrs May finds out, she'll reduce the number of bobbies in her neck of the woods which will also cut the number of folk who are measured over the limit.

    4. Kernel

      Re: Life is easier up north

      "The lower alcohol limit seems to have cut the number of folk who are measured over the limit."

      But has it actually reduced the number of deaths on the road which can be attributed to drink-driving?

      I ask this because when they reduced the limit in NZ a couple of years ago it was justified on the basis of a reduced road toll - so far it seems to have had the opposite effect, especially over the xmas holiday periods, and the only real benefit has been to government coffers.

  11. Herby

    Yes, good advice...

    "If you’re concerned that you’ve had too much to drink, it’s probably a sign that you have, and a taxi Uber is in order"

    FTFY. Got to have the IT angle in all good things.

    Of course, you might want to check the BAC of the Uber driver as well.

  12. Anonymous C0ward
    Pint

    Needs to connect to a website

    where you submit your high score!

  13. Anonymous Coward
    Anonymous Coward

    If you’re concerned that you’ve had too much to drink, it’s probably a sign that you have

    I think what the buyers of the product are worried about is are they drunk enough to be ticketed based on the results of a breathalyzer.

    Given how high that blood alcohol level is in most states, it's a safe bet it was unsafe for them to drive a number of drinks earlier.

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