Dieting May Cause Positive DUI Breathalyzer Test

Here's a bit of chemistry you may want to know if you're ever pulled over and given a breath test: dieting can cause you to test positive for a DUI breathalyzer. According to the National Substance Abuse Index, many breathalyzers measure methyl groups, which are a product of alcohol metabolism, rather than the presence of ethyl alcohol itself. This means that any chemical exposure or metabolic process that produces methyl groups may produce a false positive breathalyzer result. High protein, low carbohydrate diets, including the Atkins diet, causes your body to produce ketones or acetone, which the test reads as a possible metabolite from drinking alcohol. Other causes of false positive DUI breathalyzer tests include absorption of chemicals from pumping gas, inhaling glue fumes, handling glue or medical conditions including hyperglycemia.
In-car ignition interlock devices may test for alcohol, but non-specifically, meaning any alcohol will register a positive result. Strict dieting may produce isopropanol, an alcohol which would make you unable to start your car.