Common Misperceptions about Ignition Interlock Devices

MYTH: An ignition interlock random retest can shut down a car in traffic, creating a dangerous hazard.

FACT: The interlock will periodically prompt the driver to take a random retest while driving to ensure that the driver does not consume alcohol after performing the initial breath test. If alcohol is detected, the ignition interlock will not turn the engine off while the vehicle is in motion. It may signal the driver to stop by blowing the horn and flashing the lights.

MYTH: It is easy to bypass the device or have someone else blow into it.

FACT: Ignition interlocks are built with anti-circumvention technology that makes it difficult to bypass. Users are trained to use specific blow patterns and there are random retests that require an additional breath sample once the car has started. Some states may require advanced technologies, such as cameras, to prove the user’s identity.

MYTH: An ignition interlock unit drains the car battery.

FACT: The device will not drain the battery unless the vehicle is not started for approximately 10 consecutive days.

MYTH: Spicy food will cause the device to fail.

FACT: This phenomenon does not occur with devices specified for alcohol testing. Modern ignition interlocks use Fuel Cell technology which eliminates this as a variable.

MYTH: Cigarette smoke and chewing tobacco cause the device to fail.

FACT: Cigarette smoke does not affect the alcohol-specific devices; however, smoke should never be blown into any unit. Users are instructed to always take a few deep breaths before blowing into a device if they are smokers.

MYTH: Perfume, hairspray, after-shave colognes, or hand sanitizers cause the device to fail.

FACT: Most perfumes and colognes contain alcohol, but interlocks rarely react to them unless sprayed into the device directly. Interlock users should consider waiting to apply these items until after they arrive at their destination if they have concerns.

MYTH: Mouthwash and mouth spray cause the device to fail.

FACT: Mouthwash and sprays usually contain up to 30% alcohol and will definitely react as alcohol in all interlock devices. The breath alcohol concentration level can register as high as 0.25, but will dissipate within 15 minutes. Less if the mouth is rinsed with water. Interlock users are instructed to use non-alcohol mouthwash and rinse out their mouths with water before every test.