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BACtrack Keychain Operating Instructions

Below are basic operation guidelines for the BACtrack Keychain breathalyzer. For more detailed instructions and explanations, please read the BACtrack Keychain Breathalyzer Owner’s Manual.


IMPORTANT: Users must wait 20 minutes after eating, drinking, or smoking before blowing into the Keychain Breathalyzer. Failure to wait 20 minutes can provide inaccurate test results and possibly damage the sensor.

    • Before Starting 

      (Optional) Attach the mouthpiece to the folding breath tube. This enables a more hygienic sharing method, but is not required.

    • Step 1

      Press the Power button. 

    • Step 2

      When the countdown approaches 2, begin to inhale a deep breath. 

    • Step 3

      When the countdown reaches zero, the Keychain Breathalyzer will beep and a red dot will appear on the LCD. Blow through the mouthpiece firmly and continuously for five seconds until the beep sound comes on--this means it has enough breath sample. 

    • Step 4

      Once the sensor has analyzed the breath sample, the estimated BAC value is displayed. Note: for most accurate results, wait one minute between tests for the sensor to return to neutral. When testing high alcohol levels, wait 3-5 minutes between tests. 

A breath alcohol tester cannot determine the exact BAC in the blood of the test subject. Correlation between Breath Alcohol Content and Blood Alcohol Content depends on many factors, such as temperature and health conditions. Therefore, only use this device as a tool to screen for the presence of alcohol.
Many people consider a 0.02% or greater a positive test for alcohol in “zero tolerance” screening. Most states have 0.08% as the legal BAC limit for tasks such as operating a motor vehicle. Some states prohibit driving commercial vehicles or any vessel with a 0.04% BAC or higher. Many states and countries prosecute individuals for driving under the influence at any level.

Powering Off

To turn the power off at any time, leave the unit alone. Not touching the power button for 10 seconds will trigger it to automatically shut itself off with minimal effect on the life of the battery.


    • This indicates that the reading exceeds the upper limit of 0.40% BAC. Make sure the use has waited 20 minutes after consuming alcohol before blowing. 

    • If a user does not blow a sufficient breath sample, the LCD will display “FL." Press the Power button to restart the countdown cycle and retest.

    • This indicates that the sensor is damaged. Contact Customer Service support for assistance.

    • Low battery. Replace with a new AAA alkaline battery.