What does BAC Mean?

Blood alcohol content (BAC) or blood alcohol concentration is a measure of the concentration of alcohol in blood, and is represented in percentages. BAC can be measured either by blood, urine or breath testing and is often used by law enforcement to determine whether or not a motorist is "legally drunk."

BAC of 0.10% means 1 gram of alcohol per 1000 grams of an individual's blood.

In field sobriety tests, and after an arrest at a police station, BAC is often estimated from breath alcohol concentration (also called BrAC) measured using a machine commonly referred to as a Breathalyzer.

The number of drinks consumed, as illustrated by this BAC chart, is not in itself an accurate measure of intoxication, or BAC. A person's physiology and alcohol tolerance also play a big part in how easily BAC is increased. A single drink containing one ounce (28 grams) of alcohol will increase the average person's BAC roughly 0.03%, but this can vary significantly, depending on body weight, gender, and body fat percentage.

Additionally, neither BAC nor the number of drinks consumed is a necessarily accurate indicator of level of impairment. Tolerance to alcohol varies from one person to another, and can be affected by such factors as genetics, adaptation to chronic alcohol use, and synergistic effects of drugs (i.e. drinking alcohol with medication). The effects of alcohol can be different from one individual to another.

However, when it comes to law enforcement, a standard must be set. In the US the legal limit has been set at .08% (see .08 BAC Limit for Every State). A person can be considered driving under the influence (DUI) or driving while intoxicated (DWI) if his/her BAC is above the legal limit.

Related Articles:

• Effects of Alcohol
• Field Sobriety Tests
• What is a Breathalyzer?

Related Libraries:

• Legal DUI Articles
• Drunk Driving Research

Also See:

• Personal Portable Breathalyzers
• DUI / DWI Laws by State
• DUI / DWI Attorneys by State
• SR-22 Auto Insurance Quotes

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