Some foods, beverages and even alcohol-based mouthwash can cause a failed breath test in some ignition interlock devices. However, RoadGuard Interlock devices minimize this problem because they can tell the difference between breath alcohol and mouth alcohol, such as mouthwash.
Keep products containing alcohol like hand sanitizer, mouthwash, hairspray, perfume, etc. away from the device. Do not consume any food, beverages other than water, or tobacco products within 15 minutes before taking a breath test.