DUI Breath Test

Challenging a DUI Breath Test

Breath tests to gauge a driver’s blood alcohol concentration (BAC) are inherently unreliable. They are meant to work by measuring the amount of alcohol in your lungs. However, a breath test for BAC can by definition only be an estimation, and unfortunately, is subject to a myriad of influences that can result in a falsely high reading. Experienced attorney James E. Novak is able to challenge breath tests by identifying these factors, and he may be able to have the results omitted. If you would like to learn more about fighting the results of a driving under the influence (DUI) breath test, please contact our Greater Phoenix-area practice to schedule a consultation today.

Mandatory BAC Testing

Like field sobriety tests, results from portable breath tests (PBT) taken during a DUI stop are considered preliminary. They cannot be used to demonstrate guilt of DUI, and you have the right to decline either test without penalization. To bring charges, another chemical test is required. This will likely be done with a large breath machine inside the police station. It could also be done with a blood or urine test, and it might be administered at a hospital. Of the three chemical tests, urine is the least reliable, followed by breath, and lastly blood. If you refuse the mandatory BAC test after arrest, your driver’s license will automatically be suspended for one year under the Implied Consent law.

Problems with Breath Testing

All breath tests are problematic. First, they assume that the person is no longer absorbing alcohol into the blood. Therefore, someone with a slow metabolism may still be absorbing alcohol by the time they take the test. This means they are more impaired during the test than while operating the vehicle. The test can also be inaccurate if it was not administered correctly, or if the machine was not properly maintained and calibrated.

Several other circumstances and health conditions have the potential to affect DUI breath test results:

• Acetone in the breath can produce falsely high BAC estimates. This can be caused by hypoglycemia related to diabetes and other health conditions, but may also be present in normal, healthy people. Acetone levels may also be raised by medications, fasting, and certain types of diets (including high-carb and low-carb). Overexertion, fright, and anxiety can also raise acetone.
• Residual alcohol in the mouth can cause a false positive. Factors that increase levels of alcohol in the mouth include how recently you had your last drink; whether you have belched, hiccupped, or vomited recently prior to the test; and whether you wear dentures, which can trap alcohol. In addition, recent use of certain kinds of mouthwash, cold medicine, cough syrup, and lip balms can result in a mistakenly high reading.
• The flow of the breath can have a significant impact on test results. Alcohol concentration changes as the breath is exhaled, resulting in a higher concentration at the end when the breath is expelled from the bottom of the lungs closer to the alveolar sacs. If you are instructed to breathe unnaturally by blowing longer and harder than normal into the breathalyzer machine, it will register an inaccurately elevated reading.

Building an Effective Defense

Being charged with DUI does not equal a conviction. All chemical tests, including breath, blood, and urine, have the potential to be successfully challenged. With his vast experience and skill handling DUI cases, James Novak is able to create effective strategies for your defense. To find out more, contact his law offices today.