Can You Trust the Validity of Breathalyzer Results in Arizona?

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Are Breathalyzer Tests Accurate?

It’s common for people to be pulled over by law enforcement due to a suspicion of driving under the influence. The law enforcement officer may then try to determine a person’s blood-alcohol content by asking them to take a breathalyzer test. They will have to blow into a machine designed to determine the level of alcohol in their system. Should their blood-alcohol content register as, over the legal limit, they will be arrested for DUI. However, the results of a breathalyzer test are often controversial.

breathalyzer test


Many people don’t realize that the efficiency of a breathalyzer test often doesn’t meet expectations. This has caused many people to be subject to false charges. It can be important to know how a breathalyzer test works and its flaws, especially if the test results are not always conclusive.


A breathalyzer can’t directly measure the blood alcohol content in a person’s blood. So, it’s designed to measure the level of alcohol in a person’s breath. A breathalyzer uses a chemical reaction to determine the level of alcohol in a person’s system. It does this using an alcohol-based color change. It consists of a tube people must blow through and a sample chamber. A DUI attorney knows this popular alcohol screening device is not always reliable.


First, a breathalyzer can be improperly calibrated. These machines must be periodically tested and calibrated. This is done to make certain they are properly measuring blood-alcohol levels. However, testing and calibration are not always done on these machines when required and this can cause them to malfunction.

Residual Alcohol Results

Most people are responsible and watch how much they’re drinking if they know they must drive home. However, even sipping one drink for a long time could be a problem. Alcohol can stay in a person’s mouth in a residual form. It can also be absorbed in the food between their teeth if they were eating at the same time or just before. This type of residual alcohol is one reason a person might receive an inaccurate test.

Software Errors

A breathalyzer must operate properly to provide an accurate blood-alcohol level reading. This means that the software used to run it must be working properly. If there is a problem with the software, it will result in the breathalyzer malfunctioning. This can cause an inaccurate reading.

Metabolism and Temperature

The natural behavior of a person’s body can affect their blood-alcohol reading on a breathalyzer. This has to do with a person’s metabolism and body temperature. A breathalyzer is made to test the breath of a person with a temperature of 98.6°F. There is a problem if a person’s temperature is any higher. It has been proven that this can cause an inaccurate reading of up to 20%. A person’s metabolism can also impact their breathalyzer reading. People with lower metabolisms take a longer time to absorb alcohol. This could cause a person’s breathalyzer reading to far exceed the amount of alcohol in their bloodstream.

Human Error

When something goes wrong with a breathalyzer test, the initial thought is to blame the machinery. But it may also not have worked properly because of human error. The law enforcement officer administering the test may not have been trained properly, and as a result, improperly used the breathalyzer. Proving this could be a challenge for a DUI lawyer, but it is possible.

Influenced Results

If a person is extremely upset during a breathalyzer test, they may be hyperventilating. This could cause them to hold their breath. When this happens, a person’s blood-alcohol content can increase up to .81%. Hyperventilating causes molecules of alcohol to be released into a person’s trachea. They may also be a diabetic or on a certain diet that could cause them to have higher acetone levels. That can read as ethanol to a breathalyzer.

Body Reactions

A person’s natural reflexes may impact the results of their breathalyzer test. If they were to hiccup or belch, it could cause a higher blood-alcohol reading.

Simply because a person is charged with a DUI does not mean they will be convicted. Nobody should feel helpless because of the breathalyzer test result. It will take more than the result of this test to obtain a conviction. If you’re in this position, it may be time to call a knowledgeable and experienced DUI Defense Attorney like Robert A. Dodell, Attorney at Law. Contact him today. His website is

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