How Often Do I Have To Blow Into My Ignition Interlock Device?

If you’ve been convicted of DUI/DWI, chances are good that you’ve been ordered to install an ignition interlock device (IID) in your vehicle. All 50 states have ignition interlock device laws, and 29 states require you get an IID even if this was your first DUI conviction. Each state has different regulations though, so how often you have to blow into your ignition interlock device will depend on the specifics of your case and which state you live in.

You can find more information on our state laws & requirements page. We try our best to keep that page up to date, but states are changing their DUI/DWI laws all the time. If you have a specific question about your state’s laws, consult with your DUI lawyer or your monitoring agency for the most current information.

How Ignition Interlock Devices Work

Ignition interlock devices are a two part system. Your ALCOLOCK technician will install the Electronic Control Unit (ECU), which is attached to your car or truck’s electrical system — specifically, the starter. Then the handheld device (that you blow into) is attached by a cord to the ECU. Your technician will give you a full training session at the time your device is installed so that you know how to properly use it.

When you blow into the mouthpiece on the handheld device, it communicates with the ECU. If there is no detectable alcohol on your breath, you can start your vehicle. If the device detects alcohol on your breath that is above the breath alcohol content (BrAC) limit set by your program, the IID won’t let you start your vehicle. The fail level is extremely low in most states, for example, .025 or below is allowable, but blowing above that is an IID violation.

So at a minimum, you will be required to blow into the IID before you can start your vehicle. All state programs then require what is called a rolling retest. At periodic intervals, you will have to blow into the device again, to prove you are not drinking while driving. We do not advise that you give a breath sample while the vehicle is moving down the road.It’s much safer to pull onto the shoulder or into a parking lot to take the test. Your ignition interlock device will sound an alert a few minutes before the next test is required to give you time to find a safe location.

If your vehicle is still running and you blow above your program’s BrAC limit, the device will record that as a violation. If you skip a rolling retest, that will be recorded as a violation. For safety reasons, the ignition interlock device will not shut down your vehicle in the middle of traffic. But you should know, if you fail or skip a rolling retest, it will be reported to your monitoring authority as a violation. In many states, you are only allowed one program violation before you have to take your vehicle back into the ignition interlock installation service center for unscheduled service.

If You Haven’t Been Drinking But You Failed the Test

This is relatively uncommon, but it does happen. If you haven’t been drinking but you failed the test, it could be because you ate or drank something that had alcohol in it. This is why it’s always a good idea to swish your mouth with water before blowing into the device.

Some common items that contain alcohol include:

  • Mouthwash
  • Some breath mints
  • Cough syrup
  • Vanilla extract
  • Some energy drinks
  • Foods such as rum cake or pasta with vodka sauce

If you failed the test but you haven’t been drinking alcohol, you’ll want to notify your service center as well as your monitoring agency. If you have a DUI lawyer, you will want to notify them as well. A failed test, regardless of why it happened, is a program violation and could result in you needing to have the ignition interlock device in your vehicle for a longer time, or facing other legal consequences.

Get Back on the Road With ALCOLOCK

At ALCOLOCK, we believe getting an ignition interlock device installed in your vehicle should be quick and painless. Your IID will help monitor your progress towards getting full driving privileges back. We understand you want to get your life back to normal as quickly as possible. Call us at 866-700-9300 to get started, or use our contact form to schedule your installation.