BAC Calculation

Blood Alcohol Concentration

What is blood alcohol concentration?
Blood alcohol concentration (BAC) refers to the amount of ethyl alcohol that is present in your blood stream.  Your blood alcohol concentration can be determined through the administration of a breath, blood, or urine test. 

Blood Alcohol Concentration and DUI Arrest
When you are stopped for driving under the influence, you will be asked to submit to a breath alcohol test by the police officer.  You have the right to refuse to take to the portable preliminary breath alcohol test in the field, but it is a violation of law to refuse to take the breath alcohol test administered at the station.

If you consent to the breath alcohol test, and your BAC is 0.08% or higher, you will be placed under arrest for driving under the influence.  In Virginia, it is illegal to operate a motor vehicle with a BAC of 0.08% or higher. 

Breath Alcohol Testing - During a breath alcohol test, you blow into an instrument such as the Intoxilyzer 5000.  Your breath alcohol concentration is related to your blood alcohol concentration.  By measuring your breath alcohol concentration, the police can figure out your blood alcohol concentration (BAC).  Most states, including Virginia, have adopted 0.08% as the standard.  This means there is 0.08 grams of alcohol present per 100 milliliters of blood. 

Blood Alcohol Testing - Through a blood alcohol test, your blood alcohol content can be directly determined.  Blood testing is the most accurate way to determine your blood alcohol concentration.  During a blood alcohol test, blood is drawn from your arm, and then it is analyzed.  If the blood test reveals your blood alcohol concentration to be 0.08% or greater, you are considered intoxicated.   

Blood Alcohol Concentration and Administrative License Suspension
If your Blood Alcohol Concentration is measured by the police at .08 or greater (or .02 for those under twenty-one) or if you refuse to take the test, the police are required to suspend your privilege to drive in Virginia for a period of seven days.  For a second DUI or refusal, the period is sixty days.  For a third or subsequent DUI or refusal, the suspension lasts until the DUI trial.

Inaccurate Blood Alcohol Test Results
Most people are under the impression that blood alcohol tests are 100% accurate, but this is not true.  In many cases, it has been discovered that the person’s reported BAC was inaccurate.  Inaccuracy can stem from many things, including:  defective test equipment, improper test administration, unlicensed or uncertified person administering the test, and police radio interference (common with breath alcohol tests).  Additionally, you may have an inaccurate BAC if you ate before the test, used mouthwash, hiccupped, vomited, or wore dentures. 

Fairfax DUI Defense Attorney: The Law Offices of Scott C. Nolan
If you have been charged with DUI in Fairfax, you need to consult with a skilled DUI Defense Attorney immediately.  The Law Offices of Scott C. Nolan has been representing clients charged with DUI in Fairfax and Northern Virginia for years.  At the Law Offices of Scott C. Nolan, each and every case is handled with personal care and seasoned experience. At the Law Offices of Scott C. Nolan, you’ll receive the thorough legal counsel and aggressive defense you need to contest your DUI charges. 

Hiring the Law Offices of Scott C. Nolan, DUI attorney
If you have been charged with DUI or an intoxication offense in Fairfax, you should contact Attorney Scott C. Nolan immediately.  Scott Nolan is an aggressive DUI defense attorney who is committed to fighting his clients’ DUI charges and protecting their best interests. 


Contact us about your legal matter today!