December 15, 2019

How Reliable are Breathalyzer Tests?


In California, a person cannot legally operate their vehicle with a blood alcohol content level of .08 percent or higher. Police routinely use breathalyzers to prove a driver is, in fact, under the influence. If the device shows a reading of .08 percent or higher, the person will be placed under arrest, his or her vehicle will be impounded and the driver will be charged with a DUI.

In most DUI arrests, the suspect will be asked to submit to a breathalyzer test. Whether a breathalyzer was taken or refused, our lawyers can help you fight a DUI charge. After all, there is much at stake, including losing one’s ability to drive a car and/or other criminal charges.

Our office can help clients during the criminal proceeding as well as with DMV hearings in order to ensure the best result possible.


Experienced DUI defense attorneys will challenge the reliability of breathalyzer test results as suspect because they are prone to operator error. Your attorney will need to determine whether the machine has been calibrated and properly maintained per state guidelines. If the maintenance of the machine can be questioned, so can the legitimacy of its results. Other areas of inquiry include challenging the police officer’s training and experience with the machine’s operation.

By doing a little bit of research in the case, a good DUI attorney can determine how best to challenge the breathalyzer results.


In California, every driver on the road implicitly agrees to a chemical test to determine their blood alcohol level when arrested for DUI. Under this law, any DUI suspect who refuses to submit to a chemical test will have their license automatically suspended.