What is the legal limit on a breathalyzer test?
Therefore, women should refer to the female chart. All states have set .08% Blood Alcohol Concentration (BAC) as the legal limit for Driving Under the Influence. For commercial drivers, a BAC of .04% can result in a DUI conviction nationwide. Subtract .01% for each 40 minutes of drinking.
So that means for every hour you are not drinking, .015 of the alcohol in your body is being metabolized and disappearing from your body (thanks to David J. Hanson, Ph.D. for this information). So, if your BAC was 0.08 (legally impaired), it would take about 5.33 hours for the alcohol to be eliminated from your body.
- BAC goes down at a slow and predictable rate. This is because your liver can only metabolize a predictable blood alcohol concentration per hour. The normal body will metabolize between .015 percent and .020 percent BAC per hour. We use a conservative .016 percent BAC per hour in the following charts.
- Adding up your units. If you drink a large (250ml) glass of wine, your body takes about three hours to break down the alcohol. If you drink one pint of beer, your body takes about two hours to break it down. One pint of strong lager is equivalent to three units, so this will take longer.
- It takes 30 minutes to feel the effects of alcohol. It may take an hour to metabolize a drink, but it takes approximately thirty minutes before you feel alcohol's effects. This is a good gauge for pacing yourself. Drinking more than one drink every 30 minutes means you are probably drinking too much, too fast.
That means, if someone blows a .08 or higher when given a breathalyzer test, they're considered too drunk to drive. But that number's a bit abstract if you don't know what it's measuring. The number on the breathalyzer refers to your blood alcohol concentration (sometimes referred to as blood alcohol content or BAC).
- The PBT is limited as to when it can be used in court and is generally not admissable as evidence during the trial of the case. However, the Breathalyzer administered in the police station is the test which may be admissable as evidence at trial to prove the offense of Driving Under the Influence of Alcohol.
- Therefore, women should refer to the female chart. All states have set .08% Blood Alcohol Concentration (BAC) as the legal limit for Driving Under the Influence. For commercial drivers, a BAC of .04% can result in a DUI conviction nationwide. Subtract .01% for each 40 minutes of drinking.
- BAC stands for blood alcohol concentration and is the percentage of blood that is concentrated with alcohol. It is a useful way of determining how much alcohol a person can consume. A BAC of .10 means that .1% of your bloodstream is composed of alcohol. BAC charts are only tools, and do not guarantee specific BAC.
Updated: 18th September 2018