The Problems with Breath DUI Testing

May 22, 2019


Breath testing for DUI can be very problematic. However, most drivers, and far too many attorneys, really do not understand how frequent these problems arise. In this post, I will highlight some of the common problems with DUI breath testing.

Breath Testing Machines Cannot Measure Just Ethanol

Ethanol is the substance in wine, beer, or other alcoholic beverages. Breath testing machines cannot measure ethanol exclusively. The machines measure substances that carry a similar chemical makeup and therefore, they can falsely produce a high number due to the presence of isopropyl alcohol and methanol.

Isopropyl alcohol, more commonly known as rubbing alcohol, is a common disinfectant that can be found in hand sanitizers. It can also be found in many cosmetics and lotions. Methanol is commonly used as an industrial solvent. It can be found in paint thinner, for example.

Because breath testing machines are not specific to ethanol, a driver who uses common products like hand sanitizer, mouth wash, or paint thinner can produce an inflated (and, thus, inaccurate) Blood Alcohol reading.

There is a Difference Between a 105 lb Woman and a 280 lb Man

Every person’s body is different and processes alcohol differently. Breath testing machines measure the content of alcohol in a breath sample and then convert that to an estimated blood alcohol content. The conversion factor that is used is called a partition ratio. However, since every person is different, partition ratios are also different and the assumed ratio can lead to an artificially high blood alcohol reading.

Residual Mouth Alcohol

Another problem with breath testing is over reporting due to residual mouth alcohol. If someone has consumed alcohol just before the breath test, there may be alcohol left over in the mouth. The machines falsely interpret this to mean that there must be more alcohol in that person’s system than the actual amount of alcohol. This is why police officers are required to administer an observation period before testing a driver. If this procedure is not followed correctly, the breath machine can report a high number.

As you can see, there are many problems with breath testing machines. Unfortunately, most attorneys do not know enough about the science behind the testing to be able to identify and challenge these issues in court. This is why it is important to find an experienced DUI attorney who has the knowledge and training to correctly fight your case.

Attorney Mike Bowser is a Board Certified DUI Specialist. This means he had to pass a rigorous examination process that tested his knowledge of DUI science. If you want his superior knowledge and skill on your side, all you have to do is call 888-526-9737 and schedule your free consultation.

What is the Bowser Law Difference?

Mike Bowser has unique experience and knowledge which he uses to protect his clients.

  • Mike Bowser is the only Board Certified DUI Defense Specialist who practices in MA, NH & ME. This means he had to pass rigorous examinations and interviews about his knowledge of DUI law to become certified.
  • Because he practices in all three states, Mike Bowser knows how to handle the complications that arise when you are charged as an out of state driver.
  • Clients who have hired Mike Bowser LOVE him! Take one look at his reviews and you will see why Mike Bowser is The Most Reviewed 5 Star DUI Defense Lawyer Practicing in MA, NH & ME!
  • He uses his deep understanding of forensic science to pick apart the evidence against you and looks for errors that he can challenge. He then carefully prepares your case with the goal of highlighting these issues and putting you in the best possible position.
  • He is a ruthless cross-examiner who is at home in the courtroom. Judges, prosecutors, and police officers often praise his professionalism and knowledge.

If you are facing a DUI charge, don’t delay. Call now to setup your
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(888) 526-9737

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