BAC Explained

3BAC Explained

One of the most serious offenses that a driver may be charged with is driving while impaired, DWI. All states have DWI laws in place to restrict driving a motor vehicle while impaired due to the use of drugs or alcohol. In North Carolina, the legal blood alcohol concentration (BAC) limit is 0.08%. The police may arrest a driver when their BAC is 0.08% or higher, or they are suspected of driving while impaired. Some people think there is a magic number of drinks they can consume before they reach impairment, but that is not true.


How the Body Utilizes Alcohol

When you consume any food or beverages, the body begins to use them. The stomach and intestines absorb some of the alcohol rather quickly, and it enters your bloodstream. Your liver metabolizes alcohol, which the body considers a toxin. However, if you drink too much or too quickly for your liver to process the alcohol, you will become intoxicated. Intoxication happens when your bloodstream has a high level of alcohol. In general, the average person’s liver can process about one alcoholic drink per hour.


Charlotte DWI Lawyer Brad Smith answers the question: “Are breath test results always accurate?”


Factors That Determine BAC

There are a variety of factors that determine a person’s blood alcohol concentration. Your weight and age are important variables that may impact BAC. For example, a person who weighs more than average will likely be able to drink more alcohol before reaching impairment. Other factors include whether you ate before you began drinking alcohol, how quickly you consume alcoholic beverages, and the amount of alcohol you consume. Typically, beer and wine contain a lower percentage of alcohol than hard liquor. A regular can of beer usually has about 5% alcohol.


BAC Levels and What They Mean

Alcohol in the system acts as a depressant. It can affect the central nervous system and all your body’s organs. A BAC of 0.00% means that there is no alcohol present in the blood. When your BAC is under 0.08% in North Carolina, it means that you are not considered impaired, and it is legal for you to drive (unless you are under the age of 21). At 0.08% BAC, you will have reduced muscle coordination and begin to have poor judgment. Your reaction times are also reduced. A BAC of 0.15% is significant intoxication, and you may be slurring your words, unable to stand or wine-DWI-Charges-in-North-Carolina-Defense-Attorney-scaledwalk, and nauseated. A BAC of 0.40% BAC is considered a fatal level.


Can I Determine My BAC Before I Get Behind the Wheel?

There is no sure way to know your BAC without testing. The amount of alcohol you consume one day may not affect you, while the same amount another day might make you intoxicated. Further, a person may develop a tolerance to alcohol, so they may not feel impaired, even if their BAC is high. There are personal testing devices that you can use to measure BAC. However, the only sure way to know that you are not impaired by alcohol is to refrain from drinking.

  • Breathalyzer Tests – A police officer may take a preliminary breath test using a device called a breathalyzer. The device measures your BAC by measuring your breath. At the police station, you may be given a more sophisticated test using a breathalyzer machine to measure BAC.
  • Blood Tests – A blood test is the most reliable way to measure BAC. Blood is drawn and then analyzed to measure the BAC.

It is important to note that the BAC test should be done as close to the time you are driving as possible to obtain an accurate measurement of your BAC at the time. Your BAC can continue to go up for some time after you take your last drink. Then, it will begin to go down. A BAC is only considered accurate when you take the test within six to 12 hours after your last alcoholic drink.


If you have been charged with DWI, you will want to seek legal guidance as soon as possible. There are some ways to successfully defend DWI, depending on the circumstances. It is always better to talk to an attorney right away since there may be some things your attorney can do immediately. To learn more about fighting DWI charges, contact us today at Arnold & Smith, PLLC, at (704) 370-2828 for a consultation.






The criminal defense attorneys at Arnold & Smith, PLLC make it their mission to zealously defend their clients on a wide range of criminal matters at both the state and federal levels. These matters may include any charge from traffic offenses; DWI/DUI; drug charges (from simple possession to possession with intent to distribute and trafficking); gun permit denials; weapons offenses; and property crimes (larceny, breaking and entering, robbery, fraud, embezzlement, white collar offenses); to sexually related offenses (indecent exposure; sexual assault, crimes against nature, removal from sex offender registry); and violent crimes (domestic violence; assault; manslaughter; homicide, murder). Other legal issues that Arnold & Smith, PLLC criminal clients may be facing include restraining orders, restraining order and probation violations, expungements; appeals; and immigration issues related to criminal charges. Our criminal defense attorneys are passionate about ensuring that individuals empower themselves by being informed about their constitutional rights, and stand at the ready to fight in the defense of those facing criminal charges.



Definition: BAC from 10 CFR § 26.5 | LII / Legal Information Institute (

Official NCDMV: Driving While Impaired (


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