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Breath Testing Machine Inaccuracies

Following a DUI arrest, the police officer administers a Breathalyzer test to determine whether your Blood Alcohol level is over the current legal limit of 0.08%. But many times BAC readings can be incorrect, with the reading being as much as 23 percent higher than it should be due to inaccurate breathalyzer testing. There are a variety of reasons for these problems and a growing number of courts across the country are finding the truth regarding these machines and suppressing BAC results. The following are a few basic problems to look for.

The manufacturers took this to be a sophisticated device with the potential for accuracy, however, it does have design flaws. But these flaws are issues a DUI defense attorney can challenge.


There are many problems with the accuracy of breathalyzers in general. For example, if you were to suffer from diabetes, esophageal hernia, heartburn, liver disease, or other illnesses this can cause inaccurate readings from the machines. If you were to be chewing gum or have taken cough syrup before you drove, this can also cause a false result. Also, the residual alcohol in your mouth can distort the results of the unreliable portable breathalyzers.

Common food items, like white bread or pizza dough, contain yeast that produces a low amount of alcohol (EtOH). When a person blows into the machine after having eaten bread, the Intoxilyzer will detect an elevated alcohol amount in the breath sample. This type of alcohol is different than that in a person’s bloodstream and does not affect driving abilities, but the machine cannot differentiate between the two.

Certain conditions, such as gastroesophageal reflux disease (GERD), can cause a person to inadvertently regurgitate the contents of his or her stomach. Alcohol from a person’s stomach, when refluxed, will then be present in the same airway which a person blows out for breath testing. In this instance, raw alcohol from the stomach will cause a falsely elevated breath test reading.

A fever will also cause the breath test readings to be falsely elevated by 6% for every one degree Celsius above a person’s normal body temperature.


When a breath machine operator tests a DUI suspect, they have to follow a number of basic steps to ensure that the breath results are accurate. First, the operator needs to make sure that electronic devices are removed from the breath testing room (because the machine may be affected by radio waves). Second, the operator must watch the person arrested for 20 minutes prior to taking the first breath sample. This task is to ensure the individual does not put food or liquid in their mouth or belch. Finally, the operator must take two breath test samples that are within .020 agreement of each other. If anyone of these requirements is not met, then the breath test results may be ruled invalid.

Therefore, while police officers are the ones administering the tests, this does not mean that they know how to operate the machine properly. Often they are given only minimal training on the device. A good DUI defense attorney will find out whether or not the officer in your case correctly used the machine.

So before you give up hope, let your defense attorney thoroughly review your case. They may just uncover something you never would have thought about.


Under Maryland’s “implied consent” law any individual who drives a motor vehicle public or private roadway is deemed to have given consent to be chemically tested if and when a police officer feels that driver is impaired. If you are stopped by a police officer and you refuse to take a Breath Test, your license will be suspended for up to 120 days. Moreover, refusing the test does not guarantee that you won’t be convicted – you could be found guilty of a DUI even if your refusal means that the state does not have proof that your BAC was over.08%, the legal limit. In fact, the prosecution can use your refusal against you by arguing that you refused the test because you knew that you were intoxicated and guilty of DUI. The penalties for a first offense in Maryland may include a $1,000 fine, and up to a year of jail time.

Get Help with Your DUI. If you are charged with a DUI in it is in your best interests to find the best DUI attorney in MD. A highly trained DUI professional can help challenge these charges and protect your rights and future. Do not hesitate to contact the attorneys at Alpert Schreyer today. Call (301) 321-7277 or fill out our online form to receive a confidential evaluation of your case by an experienced attorney.