Some New York motorists who have acid reflux or diabetes or even those who are in ketosis might cause a false positive on some types of breath tests used by law enforcement to determine blood alcohol content. These conditions can cause a person to breathe out isopropyl alcohol, and some say not all breath tests can distinguish between this and ethanol alcohol.
One of those people is a Texas attorney who got charges dropped against his client who was on a low-carb diet that put him in ketosis. He says that no peer-reviewed studies have been done to show that breath tests that use fuel cells to determine a person's blood alcohol content can tell the difference in ethanol and isopropyl alcohol. This claim is disputed by manufacturers, who say there are no issues with their products. However, there is an article published in 2006 by a professor of forensic technology that examines the case of a man on a low-carb diet who was unable to activate his company vehicle. The vehicle had a breath test device on its ignition, and it used fuel cells.
People who are accused of driving under the influence and who know they are sober might ask to be tested on the infrared spectroscopy devices at the station. Another option may be requesting a blood test.
For a person who is facing DUI charges, an attorney might look at whether the test was administered correctly and whether any other factors might have caused a false positive or made a person appear to be drunk. An attorney might also examine whether the person's rights were violated at any point in the process. When the evidence appears to be strong, however, it might be possible to negotiate a plea bargain, which can involve pleading guilty to lesser charges and getting a lighter sentence.