In Wisconsin, it is unlawful to operate a vehicle if you have a blood alcohol concentration (BAC) at or above 0.08%. While officers can smell your breath and monitor your actions, they are likely to want to gather more concrete proof of your BAC. Asking you to breathe into a testing device is how the police try to achieve this goal.
Alcohol breath testers should correctly measure your BAC. Regrettably, that is not always the case, as many factors can lead to false-positive results. These include the foods you eat, the medical conditions you have and the medications you take. Vaping may also cause you to fail an OWI breath test.
E-liquids may contain ethanol
A recent study from Virginia Commonwealth University found the e-liquid that goes into electronic cigarettes often contains ethanol, which is a type of alcohol. In fact, out of 56 e-liquid samples researchers tested in the study, only three did not have ethanol. Even more alarming, many of the tested e-liquids contained 10% or more of it.
Ethanol registers on breath tests
While the ethanol in e-cigarettes is not likely to be sufficient to drag your BAC over the legal limit, residual ethanol in your mouth may register during a breath test. If you vape shortly before or during your OWI stop, the testing device may erroneously believe your BAC is 0.08% or higher.
It is not illegal for most Wisconsinites to use e-cigarettes, of course. Ultimately, if you can prove a testing device gave an erroneously inflated reading because of your vaping and not your drinking, you may have a valid defense against the OWI charges you are facing.