Alcohol metabolizes at 0.015 blood alcohol content per hour, so a peak of 0.03 blood alcohol content dissipates in two hours, according to the Law Dictionary. The length of time a breathalyzer detects alcohol in the breath is dependent on several factors, including peak blood alcohol levels.
The type of alcohol consumed, rate of consumption and amount of food on the stomach all affect the rate of metabolism. Some people metabolize alcohol at a faster rate than others. Even though a person shows no signs of intoxication, the breathalyzer continues to detect alcohol in the breath, notes Lifeloc Technologies. A person with twice the legal limit of alcohol requires more than 10 hours to sober completely. After five hours, he is still likely over the limit for driving.