An attorney in Texas got a man's DUI charge dismissed after he was able to demonstrate that the man was in ketosis from a low-carb diet at the time of the breath test. The man had performed normally during sobriety tests, but his blood alcohol content appeared to be above the legal limit when a breath test was done. However, ketosis can cause a person to blow out isopropyl alcohol, and some types of breath tests may not distinguish between this and ethanol alcohol.
The device most law enforcement agencies have at their stations, which uses infrared spectroscopy, can distinguish between the two types of alcohol. According to the attorney in Texas, the breath test devices that law enforcement generally carry in their cars, which use fuel cell technology, have never been demonstrated in a peer-reviewed study to distinguish between the two types of alcohol. Furthermore, a professor of forensic technology wrote a paper about a man who was on a low-carb diet who was unable to start his company's vehicle, which required a breath test. That device also used fuel cells. However, manufacturers say that their devices are accurate.
Other conditions, including acid reflux and diabetes, may also cause a person to breathe out isopropyl alcohol. Combined with a small amount of alcohol, it could be enough to put a person over the legal limit.
A person who is facing charges for drunk driving may want to consult an attorney about the options for criminal defense and drunk driving. In addition to looking into whether the person might have a medical condition that could resemble intoxication, the attorney might also examine the accuracy of the test and what prompted the traffic stop. If the person's rights were violated at some point in the process, the case could be dismissed.