BAC

You have probably heard the term “BAC” in reference to the Driving Under the Influence Laws but what exactly is BAC? An Orange County DUI defense against BAC lawyer can explain.BAC stands for Blood Alcohol Content and refers to the scientific measurement of alcohol in the blood of an individual. Every tenth of a percent expressed represents one gram of alcohol content per 1,000 grams or 1,000 milliliters of blood. The legal BAC limit to drive in California is .08%. Thus, a person who has over 800 milligrams of alcohol in 1,000 grams of blood—or expressed another way: for every 100 mL of blood, there is 8 grams of alcohol in the blood stream— is at the BAC limit for driving.

Most often BAC is measured by a breath test. How can a breath test measure how much alcohol is running through an individual’s blood stream? When alcohol enters the body it is absorbed by the blood stream and enters the liver where is metabolized (broken down). This process equalizes the amount of alcohol in the person’s body. That is, the alcohol is no longer confined to the blood but is disbursed throughout the body. Without getting into the scientific explanation, the breathalyzer simply measures the amount of alcohol in one’s breath emanating from the lungs. Breath mints or other “tricks” cannot fool a breathalyzer because the test measures the alcohol content from the air in the driver’s lungs not the smell in the driver’s mouth. For further discussion regarding how the body metabolizes alcohol, you might take a look at my blog post“ Does One Drink an Hour Keep You Under .08?”. I am a DUI defense against BAC lawyer in Orange County who has handled many of these cases.

When you are charged with DUI, your BAC will be the primary, if not the only, evidence against you. Driving with a BAC above .08% is illegal in California. It doesn’t take many drinks to reach that level and depending on your size and how fast the drinks are consumed, just two glasses of wine (for example) can put you over the limit. A BAC over .15% calls for enhanced penalties under California law.

There are potential challenges to BAC evidence. Among these challenges is what is known as “rising blood alcohol.” I mentioned earlier that alcohol is first absorbed by the bloodstream and then metabolized by the liver. Depending on the individual’s metabolism, body size and other factors, this process can take up to three hours. If the absorption process has not completed, the blood alcohol level is still rising. So let’s say you are driving very soon after a few drinks. The alcohol you imbibed may still be in your bloodstream and not yet entirely metabolized. But then you get stopped and say 20 minutes later a chemical test is performed. By then the alcohol may have completed its circuit through the liver. In other words, the BAC continued to rise after you stopped driving. What matters is what your BAC was when you were driving, not what it was 20 minutes after you stopped driving. It may seem to be a difficult defense to present, and indeed it is, but if a DUI defense against BAC attorney in Orange County can show that is plausible under the circumstances, expert analysis and testimony can provide enough evidence to cast doubt on the chemical test results. This defense may be particularly helpful when the BAC results are on the low end.

Another potential challenge to the BAC results, when those results are determined by a breath analysis, is to challenge the operation of the testing equipment by challenging the operation of the device or the device itself. This potential defense is discussed in greater detail here.

Even though the measurement of BAC is a scientific measurement, it can still be challenged. Challenging BAC is often the first line of attack when the DUI charge is for a BAC just over the .08% limit or for a BAC just over the .15% threshold, which subjects the driver to aggravated charges. An Orange County DUI defense against BAC attorney, often in consultation with a BAC expert, is best able to assess the BAC evidence and determine whether a challenge to the test results is an appropriate defense.