What is Blood Alcohol Content? 12/26/14 Alcohol gets absorbed into our blood through our intestines and stomach lining. BAC is a measurement of how much alcohol has passed through and is now flowing in the blood throughout our entire body. A Breathalyzer test is often used by law enforcement and is considered a standard tool to measure BAC; it is considered accurate enough to be allowed into evidence into a court of law. Every 45 minutes, someone in the United States is killed from [...]