Some people in Virginia have medical conditions that may cause false positives on a breath test for blood alcohol content. An attorney for a man in Texas got the man’s DUI charge dropped because the man was in ketosis from his low-carb diet. In ketosis, people may breathe out isopropyl alcohol. Not all breath tests can tell the difference between isopropyl and ethanol alcohol. Diabetes and GERD are among the other conditions that could cause a false positive for similar reasons.

A professor of forensic technology wrote a paper in 2006 about a man on a low-carb diet who could not start his company vehicle. The vehicle’s ignition was equipped with a device that required a breath test. According to the professor, fuel cell breath analyzers may return a false positive. The Texas attorney reports that no peer-reviewed studies have established that such technology can distinguish between the two types of alcohol, particularly if a person has a small amount to drink. However, manufacturers say that they can.

The types of portable devices that police carry with them generally use fuel cell technology. Most police stations also have a device that the Texas attorney says can distinguish between the two because it uses infrared spectroscopy. Another option is to take a blood test although this could reveal the presence of other medications.

Penalties for a DUI could include jail time, fines and license suspension, and in some professions, a person’s career could be at risk. Some people might assume that they have few choices when facing DUI charges, but there may be options for criminal defense. Tests could have been conducted inaccurately, or a person might appear intoxicated because of another medical condition or an unexpected reaction to a prescription drug. A plea bargain, in which a person pleads guilty to less serious charges, might also be an option.