A key component of any DUI charges against you is the test the officer used to determine what your blood alcohol content (BAC) was at the time of the arrest. This can be a breathalyzer test (roadside, or at the station), or a blood test. Naturally, if the test itself is inadmissible, or flawed, it will be very difficult for the Prosecutor to prove an essential element of the crime; that you were under the influence at the time you were driving. It should be noted that California law requires the officer conducting the test to wait 15 minutes before performing a breathalyzer test on you; failure to comply will result in the test being thrown out. There are a number of ways to challenge the tests themselves, in addition to the 15 minute waiting period, which will be addressed below.

The breathalyzer test is administered by the officer who initiated the traffic stop on suspicion that you were driving under the influence. The breathalyzer itself will provide a measure of your BAC at the time by measuring the ratio of alcohol in connection with the amount of air exhaled; this is known as an “indirect value.” Since the test creates an “indirect value”, it is susceptible to attack on a number of grounds. It is somewhere between a blood test (which would actually measure the amount of alcohol in your blood), and an estimate. Suffice it to say, mistakes can happen. There are a vast number of factors that may alter the outcome of the breathalyzer test that was conducted on by the arresting officer.

  • The overall temperature of your body at the time of the test.
  • Your rate of respiration at the time of the test.
  • The length of time that has passed between the point where you were pulled over on suspicion of driving under the influence, and when the breathalyzer test is actually administered.
  • Whether or not you have recently used mouthwash, or other substances containing alcohol.
  • Whether or not bile is present in your stomach as a result of regurgitation, or vomiting.
  • A faulty breathalyzer device; either it hasn’t been calibrated properly, or it was malfunctioning. This is a very common defense, which skilled attorneys raise.
  • The breathalyzer was functioning properly, but the officer conducting the test performed it improperly.
  • Since the breathalyzer is simply applying a mathematical equation, which creates a ration of alcohol to blood content statistical arguments become valid. In this specific context, the equation (also known as the algorithm) is based off an assumption about the “average” individual. Not all people are identical in terms of what constitutes being “under the influence”, which makes the test itself highly speculative. Additionally, the factors listed above can have an impact on the value the breathalyzer comes up with. Having skill counsel on your team to fight the results of the test may be the single best way to avoid a conviction for DUI, and DUI related offenses.

The police departments around the country have come to realize that the breathalyzer test is inherently questionable. As a result, most officers administering this test typically require you to perform the test multiple times; this is an effort to strengthen the weight of the breathalyzer test. If an officer requests that you perform multiple tests, it is imperative that you do so. Failure to comply with that request may result in your driver’s license being suspended for one year. Perform the tests as requested, and contact an attorney at Los Angeles DUI Attorney Law Firm, and allow us to attempt to remove the test from evidence.

The attorneys at Los Angeles DUI Law Firm have been trained by a man with nearly 30 years of experience representing criminal defendants in a wide variety of criminal cases; including DUI offenses; Our DUI attorney has imparted his years of knowledge, his secrets to successful defenses, and his professional demeanor to each, and every, attorney at Los Angeles DUI Attorney Law Firm. The end result of DUI attorney superior tutelage is that every attorney at our firm is well versed in the art of dismantling evidence, and exposing the flaws in the test as it was conducted. This expertise will provide you the best opportunity to obtain a verdict of not guilty, or have the charges against you dropped entirely.

As mentioned above, there are a number of factors that may affect the result of the breathalyzer test. Below, we will discuss a few of those factors. Specifically, we will address the effects of: (1) mouthwash, and breath fresheners, (2) chewing tobacco, (3) GERD, or acid reflux; and (4), dentures.

The breathalyzer is designed to test only the “alveolar” air (deep lung air) from your breath. If the breathalyzer is measuring anything other than “alveolar” air, the breathalyzer becomes invalid, and must be excluded from evidence. As such, officers performing the test must wait at least 15 minutes between stopping you, and applying the breathalyzer test. This is required by California law. During this mandatory 15 minute waiting period, the officer is required to observe the individual and make sure they do not eat, drink, or smoke anything. Further, the officer is required to make sure the individual does not vomit, leaving residue in their throat or mouth. Thus, if the 15 minute waiting period does not occur, there is no argument that can be made to keep the results of the breathalyzer from being introduced to evidence against you.

        Alcohol Content (BAC)


Frequently, the result of a breathalyzer test can be tainted by the presence of mouthwash in the individual’s mouth. This is because mouthwash contains trace amounts of alcohol. There are a number of reasons why an individual may have drank mouthwash before being pulled over on suspicion of driving under the influence; most of these reasons are not sinister. Regardless, since a breathalyzer can only test the “alveolar air in your lungs to be a valid test, the fact that mouthwash may artificially increase the value the test yields this could be a basis for removing the test from evidence altogether. As mentioned above, if the Prosecution cannot introduce evidence that you were under the influence while driving, they cannot maintain a charge of DUI against you.


In some cases, the person who was pulled over on suspicion of driving under the influence has recently been using chewing tobacco. A large number of brands of chewing tobacco contain something known as “ethyl alcohol.” “Ethyl alcohol” is also found in common forms of alcohol such as wine, beer, and hard alcohol. As a result of the chewing tobacco, it is possible that the breathalyzer test will measure the “ethyl alcohol” from the chewing tobacco, resulting in an artificially inflated value from the test itself. It bears repeating, if the breathalyzer is measuring anything other than the “alveolar” air, the test is invalid. As such, if you had recently used chewing tobacco prior to your stop, and the subsequent test, it is important that you inform your attorney of that fact immediately; it may form the basis of excluding the results from the test.


A large number of people in America have what is known as GERD, or acid reflux. Many of these people do not know that the acid reflux can cause old alcohol to be present in your mouth. As a result, a breathalyzer could produce a higher result than is actually correct. Once again, if the test is measuring anything other than your deep lung air, it is an invalid test and must be excluded from evidence. If you have GERD or acid reflux, inform your attorney immediately so that they can begin attacking the breathalyzer results on those grounds.


Dentures themselves can have the practical effect of trapping old alcohol in their mouth. This is also true for dental caps, and dental bridges; they all trap alcohol in your mouth. As a result of this, a breathalyzer test could yield unusually high results, and ultimately form a flawed basis for pursuing DUI charges against you. If you have dentures, dental bridges, or dental caps, inform your attorney of that fact immediately.


If the arresting officer subjects you to a blood test, it is generally accepted that this is the most accurate measure of your true blood alcohol content at the time of the test. A blood test may also detect drugs in the individual’s system following their arrest. However, even the blood test is not immune to attacks for accuracy, much like the breathalyzer. Many errors can, and do, occur on a regular basis. Examples of the types of errors that occur with blood test include: errors in collecting the blood sample, errors in testing the blood sample, errors in analyzing the results of the tests on the blood sample. In these cases, the blood sample may “go bad” by coagulating or decomposing, which would result in erroneous conclusions. Another method your DUI attorney can employ to attack a blood test is to identify the flaws in the record keeping for your test results, failure to follow the correct procedures at the testing facilities, and contamination of the sample itself. All of these arguments may result in the results of your blood test being excluded from evidence.

In conclusion, neither the breathalyzer test, nor the blood test is perfect. The attorneys at Los Angeles DUI Attorney Law Firm will challenge the credibility of the test results, pointing to flawed methodology, and the presence of substances that were not supposed to be tested and resulted in erroneous results. The end result of these endeavors will be throwing the results into question, and the possibility of the charges against you being dropped.

Contact our office today at 424-285-5400 for a FREE consultation with our DUI lawyer today.