In California breath testing is a choice you have if you are arrested for DUI, but what you do not know about how the machine and people with certain medical conditions can hurt you. You see, most breath testing devices are prone to false positives when the subject has an ailment known as gastro esophageal reflux disorder or GERD for short. The condition causes stomach contents to ruminate up into the airway and dissipate through the mouth, when a person is administered a breath test any remnants of alcohol in the stomach can flow up through the air pipe, and enter the machine, mixing with alcohol already in the blood coming from the lungs and exaggerating the blood alcohol concentration of the subject.
The basis of the GERD defense in DUI cases is that the subject is leaking alcohol from the stomach up into the airway where it will be analyzed by the breath machine and report a false high BAC concentration. As such, it is imperative that the individual actually have raw alcohol in their stomach which necessarily implies recent drinking. In short, if the subject stopped drinking alcohol more than 5 hours before the test, there will be no issue. In addition, criminal prosecutors will argue that the machine will detect this condition and void the test. This is simply wrong.
The scientific community has addressed this issue with mixed opinions about the affect, if any, it has on ethanol concentrations for DUI suspects. One study coming out of Australia concluded the medical condition renders anyone with GERD as not a good candidate for breath tests and should be offered blood instead. The Wells and Farrar study was overshadowed in recent years by a study conducted by A.W. Jones who asserted that GERD was a non issue in breath testing within the context of drunk driving and as long as the safeguards inherent in the regulatory schemes are followed, such as a deprivation period, observation by the arresting officer, etc. then a person with gastric reflux is ok to give breath.
Many in the legal and scientific community disagree with these conclusions and urge the state to do more testing and add additional steps to the breath testing process such as inquiry into whether the suspect has the condition which would allow them to choose blood where appropriate. Whatever the law chooses to do about the issue, it remains clear that enough doubt does exist to cause concern about whether a GERD patient is truly getting a fair shake in the criminal justice system.