What factors can affect a driver’s BAC level?

There are many different factors, such as weight, that can affect a person’s BAC level after he or she consumes alcohol.

According to the California Vehicle Code, any driver who operates a vehicle with a blood alcohol concentration (BAC) level at or above 0.08 may face the penalties associated with a DUI. Although many drivers are aware of this law, many do not understand which factors impact how quickly their BAC level rises to this point and end up receiving a DUI as a consequence.

Defining BAC

Generally speaking, BAC is the amount of alcohol in a person's body compared to a specific volume of blood. When people consume an alcoholic beverage, alcohol travels through the walls of the stomach and the small intestine before it goes into the bloodstream. After it does this, it then travels throughout the body and then eventually makes its way up to the brain. This process usually takes between 30 to 70 minutes, at which point the BAC level can be measured, either via a breath, blood or urine sample. One of these 3 tests is required, and a refusal to provide such a sample can result in (1) a forced blood draw, and (2) enhanced penalties for the underlying offense. Keep in mind that if you provide a breath sample, there will be no way to retest your BAC level as a sample of your breath is not retained. Thus, blood or urine are preferred by most attorneys.

Important factors

Although it can take over an hour after consumption for alcohol to reach the bloodstream and travel throughout the body, many different factors can affect how quickly this process occurs. These include:

  • Weight - water dilutes alcohol within the body and lowers the BAC level. Since people who weigh more have an added amount of water in their body, they often have lower BAC levels.
  • Gender - compared with men, women generally have more body fat per pound and less water in their body. Since alcohol has a hard time entering fat cells, a higher concentration of alcohol stays in the blood of women.
  • How quickly the alcohol was consumed - those who consume alcohol at a rapid rate will reach a higher BAC level than if they had consumed the same amount of alcohol over an extended period of time.

The type of alcohol consumed does not have an impact on BAC level. This is because most alcoholic beverages contain approximately half an ounce of alcohol. Thus one 12-ounce beer, a shot of distilled spirits and a 5-ounce glass of wine have the same alcohol content.

Reach out to an attorney

Drivers who are pulled over for driving under the influence of alcohol in California may face serious legal and financial consequences. In this situation, one should contact an attorney to find out what legal steps to take next to defend against drunk driving charges. Often, time is of the essence.


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