There are many people who believe that there are ways to fool a Breathalyzer or ignition interlock device (IID) into thinking they’re sober. The reality is that it’s extremely difficult to do so, and you’re actually more likely to be able to trick it into thinking you’re drunk.

Tricking a device isn’t easy, and there are a few reasons why. Here’s what you should know about the popular myth that you can trick a Breathalyzer or ignition interlock device when you need to.

Could you beat a Breathalyzer or ignition interlock device’s test?

It would be difficult to lower your blood alcohol concentration (BAC) in any way that would matter to the device. However, there are some things that can increase how much alcohol appears in your system. For example, if you hurriedly use mouthwash when an officer approaches, that mouthwash, if it contains alcohol, could make your BAC appear higher than if you hadn’t used it at all.

Breathing differently won’t help either, but it might make you dizzy or disoriented. Holding your breath, breathing quickly or tapering your breathing won’t help trick a Breathalyzer.

It’s not possible to trick your IID, either. Initially, yes, you could have someone else blow into the machine to start your vehicle. However, once you’re on your way, the device may request a rolling retest. If you do not give a sample to the machine or fail the test due to intoxication, it will set off your lights and alarm, forcing you to pull over or alerting others around you of a potential hazard.

If you have been charged with drunk driving, an experienced attorney can example the possible defenses to such a charge. He or she may also be able to work with the prosecution to come to some sort of plea agreement in your case.