Alcohol is absorbed into the body at a much quicker rate than food. On an empty stomach, 20% of alcohol is absorbed immediately into the bloodstream.  The average person’s body breaks down alcohol at a rate of 20 to 30 mg/dl per hour.  The standard rate of alcohol excretion is 0.015 blood alcohol content points (BAC) per hour.  Breathalyzers use BAC to show the current measure of alcohol in your body via breath analysis.

Alcohol is either metabolized by the body or excreted via breath, sweat or urine.  Breathalyzers work by measuring the concentration of alcohol in the air exhaled by an individual.