Mouthwash’s Effect on a Breathalyzer


Today someone asked if mouthwash can affect the results of a breathalyzer and, if so, how. Since it’s not the first time that someone has asked this question, I thought that it would be a good idea to address the issue of whether mouthwash can affect a breathalyzer.

A breathalyzer is intended to analyze only the air which comes from deep within a suspected drunk driver’s lungs. The air that comes from the lungs is called alveolar air and any alcohol in alveolar air is related to the concentration of the alcohol in the blood. As the alveolar air passes from the lungs, through the mouth, and into the breathalyzer mouthpiece it can pick up residual alcohol that may be located in the mouth. This alcohol is called “mouth alcohol” and is not necessarily related to the consumption of alcohol or how intoxicated someone might be. Yet, mouth alcohol can cause a breathalyzer to produce an erroneously high blood alcohol reading.

So what causes mouth alcohol?

Mouth alcohol can be cause by many things. Cough drops containing menthol can get stuck in the teeth and cause an elevated BAC reading. Breathalyzers can detect alcohol that may be trapped in the small crevices of dental work or mouth piercings. Belching, vomiting, smoking, and chewing gum can cause vapors of alcohol located in the stomach to rise into the mouth. And yes, mouthwash can linger in the mouth after it is gargled and it, too, is mouth alcohol.

Although none of the above mentioned causes of mouth alcohol leads to intoxication, all of them can cause a false-positive BAC reading on a breathalyzer.

The answer is “yes.” Mouthwash, along with a number of other things, can cause a breathalyzer to produce an incorrect blood alcohol reading which, in turn, can cause a person to be falsely arrested for DUI.

This entry was posted in Chemical Tests, DUI Laws, Field Evidence and tagged , , , . Bookmark the permalink.

26 Responses to Mouthwash’s Effect on a Breathalyzer

  1. Rich Ronning says:

    My wife blew a .054 from mouthwash on an interlock system and they revoked her license and made her start over from day one after being on it for 18 months of the 3 years she was given. WTF?? Can we fight this in the state of MN.?

    • PC Plod says:

      Erm no… they test with a evidential test at the station mouth wash effects would not be so long lasting she was drunk and deserves prison

      • Dave says:

        Youre an idiot. You dont know a damn thing about her. You also dont know a damn thing about the law or alcohol because the legal limit is 0.08 and she blew a 0.05. Secondly- he said “on the interlock” not “at the station” so you clearly cant read either.

  2. Lawrence Taylor ESQ says:

    Rich,
    I’m sorry for your troubles.
    We can definitely fight for your rights and work to getting this decision reversed.
    The first step is to call my office for a free consultation to review your case. Please call to schedule an appointment: 877-777-3449.
    I’m here for you Rich.

  3. Benjamin says:

    I was test positive for alcohol by means of a breatherlizer.Half an hour pryer to the test i flush my mouth with corsodyl,is it possible

  4. Felisha Mitchell says:

    My seventeen year old son was pulled over and charged with minor consumption. He had just rinsed his mouth out with Listerine and had finished breath mints before he was pulled over. He blew a 0.037 is what the officer told my mother when he realeased my son to her but the officer put in the report that he blew 0.05. My truck that he was driving was impounded It cost me $180 to get it out of impound. We havent been to court yet but I already feel like we are being railroaded. We could use some help.

  5. Emily fresquez says:

    how will it get dropped? i have court tomorow and im 19
    with the same proplem

  6. todd says:

    Got pulled over 2 weeks ago , cop said I was weaving blew .10 told them both I had mouthwash ed due to cigar smoking, not to mention having had a stroke 3 years ago and no balance so I failed the field test

  7. Rachel says:

    I did have 2 glasses of wine hours before driving but went through a check point i was honest about the two hours ago i didn’t think i had done anything wrong i later rewent through all steps before i got in my truck i washed my mouth with mouth wash they are saying.10 im so shocked i had lunch after my wine i saw places in the city i was fine could this be true?

  8. Rosa says:

    Rachel. I also had drank 2 glasses of wine I told the officer and I rinsed my mouth with listening and chewed gum and I blew 0.09 and trust me.officer tested my abc’so and counted backwards and the pen test leg test and he still arrested me he said my eyes said I was intoxicated.I am so scared right now

  9. Rosa says:

    Oops spell check listerine

  10. Beatles4Ever says:

    This thread has helped me greatly tonight so thank u everybody. But I have a question that someone can hopefully honestly help me out very soon because I have work in a couple hours. The question I have is how much alcohol will technically be in your system if you use listerine (or any other mouthwash that contains alcohol) before work? I usually get non-alcohol mouthwash but I ran out of that so now I’m back to listerine haha. This is a new thing to me that is kinda worrying me. I’m sorta young like I’m nder 21 so I can’t legally drink alcohol at all. Where I live we have a zero tolerance for underage people driving with any bit of alcohol in their body so if I get breathalyzed I’m gonna get some bad shit coming my way. I just got a delivery driving job so I feel like this is kind of important in case I get pulled over cuz I’ll lose my job and get into stupid court issues. Sorry for rambling haha but how much alcohol will be in my system in like 3 hours after I use the listerine? I tried to google it but ended up getting a lot of different answers

  11. Beatles4Ever says:

    please respond as soon as anyone is able to. Sorry if I’m just being paranoid for no reason. I’m just a pretty new driver and I’m trying to learn as much as I possibly can

  12. Peggy says:

    Had someone say he used scope. When blood work was done for alcohol it showed .03. Is this possible?

  13. Jay says:

    I used mouthwash and blew a false positive on my breathelyzer at 10 and then again at 10:10 and again at 10:50 how is this possible and how should I argume my case against this bullshit

  14. Goodropi says:

    I. Got failed a breath test at probation for a little over an hour the other day. I had used the green listerine and now my po is making me go to jail for 20 days. I have not had a bad UA or failed a breath test in 4 months. I don’t know what to do because the 20 days should have been waived and now I am losing my job and everything.

  15. Jan says:

    If you used mouthwash and had no drinks, reuse the breath test and make them take you to the hospital for a blood test.

  16. Dean says:

    I use prescription mouthwash 12% alcohol with my interlock and sometimes it takes up to 30 minutes. I get warns, no fails. I am under doctors care for infection. So, not to much probation can do about it.

  17. Christopher says:

    How long does it take for me to pass the breathylizer after using Listerine?

  18. mike says:

    i blew a .27 after leaving my house 10 mins later a .07 and then a .00000. now im being punished cuz i ran out house in a hurry after using Listerine. anyway to beat this???

  19. mike says:

    10-15 min between each bac.

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