Breathalyzer depicting a .02 blood alcohol level.


If you took a breath test after you were pulled over for DWI, and you “failed” the test, this article will provide you with information on the test itself and what you can still do to fight your case.

The breathalyzer is the machine you are going to blow into when an Officer pulls you over for DWI (Driving While Intoxicated) or DUI (Driving Under the Influence).  You would blow into the small cylinder as shown above, and your blood alcohol content would be revealed by digital number on the front of the machine.  In the picture above you see the .02.  In most states, the legal limit is .08 BAC (Blood Alcohol Content).  This means that if you blow into that little machine and blow .08 or higher, then you are considered legally intoxicated. No matter how clear minded you feel, no matter how coordinated you are, you are likely going to be arrested from Driving While Intoxicated.

Did you Get Pulled Over for DWI? Need a DWI Lawyer in San Antonio, Texas or surrounding cities? Call us! (210) 271-2800.

Facts About the Breathalyzer

A person’s pattern of breathing just prior to the breath test can alter the concentration of alcohol in the exhalation.  I have read reports that state that holding your breath for a short time before exhalation can increase the alcohol concentration by 15%.

Many people have wondered whether alcohol in the mouth, such as MOUTHWASH, will effect the breathalyzer results.  The answer is yes.  The breathalyzer is supposed to show results only for alcohol in the blood, but the alcohol in the mouth as well can change the test.  This is one reason why a person taking the test would have a more accurate result if they took two tests 15 minutes apart (enabling the mouth time to clear up any present alcohol).

Accused of DWI? Took a Breath Test?

Now remember, if you are accused of driving while intoxicated, the state has to show you were intoxicated while you were driving.  If a breath test is administered an hour after you were driving, that breath test could be inaccurate.  That is, your blood alcohol concentration can actually go up over an hour, which means the test can reveal you are currently intoxicated, but the question is, WERE you intoxicated when you were driving?

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Another relevant factor regarding the accuracy of the breathalyzer test is temperature.  The breathalyzer has to be calibrated using a sample.  The sample has to be done using the proper temperature.  If the temperature is inaccurate at the calibration stage, then the breathalyzer will give inaccurate results.

Above is a picture of the intoxilyzer 5000– this is the machine used in San Antonio for breath tests.  Its an untrustworthy dinosaur.

A Summary of Reasons The Breath Test Can Be Wrong

  • 1.  You blew with the wrong breath pattern.
  • 2.  You held your breath before blowing.
  • 3.  You had alcohol in your mouth
  • 4. The Machine was calibrated at the wrong temperature
  • 5.  The test was taken hours after you were driving.

All of these factors and many more can result in an improper DWI BAC level result.  Hire a Cook & Cook Lawyer  We can help you.

Things that can go wrong with the Intoxilyzer 5000:

  • If you have been inhaling certain compounds such as paints, thinners, or glues for a long period of time, this can effect your results depending on the configuration of the Intoxilyzer 5000.
  • A burp, can create a higher amount of alcohol in the mouth which will change the rest result than what is actually in your system.  (proponents of the machine claim that the machine measures only deep lung air for its measurement, but the ability to do so has been disputed)
  • If your temperature is higher, then the alcohol in your breath is higher.  So, if you have a temperature, you can fail a breath test you would otherwise pass!
  • The Intoxilyzer 5000 is just a machine.  Machines Break. Has your smartphone or computer every shut down on you or run the wrong way?  Same thing can happen with this breath test.  The difference is this can land you with a Drunk Driving Label for the rest of your life.

It goes without saying that we know the possible defenses when it comes to you DWI case involving a breath test.  Call us. The consultation is totally free (210) 271-2800.  Or email me at