What Is BAC and How Does It Affect a DWI in Texas?

February 27, 2024 | By Fulgham Hampton Criminal Defense Attorneys
What Is BAC and How Does It Affect a DWI in Texas?

If you are charged with Driving While Intoxicated (DWI) in Texas, one of the most important factors in your case may be your BAC. But what does BAC stand for? In criminal situations involving the consumption of alcohol, BAC stands for blood alcohol concentration or the amount of alcohol found in someone’s blood. An experienced DWI attorney in Fort Worth can assess your situation, analyze evidence, challenge legal aspects, and advocate for reduced charges or dismissal.

Depending on your age and possibly your driving status, the legal limit of alcohol in Texas will vary. As a result, you might be arrested for different DWI or DUI charges depending on your unique situation.

Typical Drivers Over the Age of 21

Under Texas DWI laws, a driver who is 21 years old or older is considered legally intoxicated if their BAC is 0.08 percent or greater. Most DWI defendants fall into this category, and these typical drivers usually face a Class B misdemeanor DWI charge as a result of their BAC results. If a typical driver’s BAC is measured at 0.15 percent or more, they can be charged with a Class A misdemeanor, which is a more serious crime that comes with additional penalties.

Drivers Under the Age of 21

BAC Test of Drivers Over the Age of 21

Since drinking alcohol is not legal in Texas for people under the age of 21, drivers who are younger than 21 are not allowed to have any trace of alcohol in their systems. This means drivers who are younger than 21 with a BAC showing any amount of alcohol can be arrested for Driving Under the Influence (DUI) in Texas.

Commercial Drivers

Another exception to a typical driver’s legal limit for alcohol in Texas applies to commercial truck drivers. Due to the dangerous aspect of their job, should an accident occur, commercial truck drivers can be charged with DWI in Texas if their BAC measures 0.04 percent or more.

Because a Texas DWI charge is an extremely serious offense, it’s crucial to understand the factors that affect BAC levels when considering how to defend a DWI charge. To learn more about your possible defenses and how Texas DWI laws impact your personal situation, consult with a dedicated Texas DWI lawyer right away.

How Is BAC Tested?

Blood alcohol concentration, or BAC measures the amount of alcohol found in someone’s bloodstream at the time of the test. Total alcohol content can be determined by testing someone’s breath, saliva, blood, or urine. The most common testing method used by law enforcement members at the scene of a DWI arrest is breath testing with a breathalyzer device.

Factors That Affect BAC Results

Now that you understand what BAC stands for let’s look at the factors that affect BAC levels in general. Keep in mind nothing can reduce your BAC except the passage of time. Coffee, a cold shower, or drinking copious amounts of water will not help you sober up any faster. 

Whether you submit to a BAC test at the arrest scene—or later if you are arrested and placed in police custody—a slight difference in your BAC results can change the trajectory of your criminal charges.

Unless you have a breathalyzer or ignition interlock device in your car, you likely do not know what your blood alcohol content is at any given moment. The difference between 0.07 percent and 0.08 percent is small in decimal numbers but big when you consider the thousands of dollars in fines and fees that you might have to pay after a DWI arrest.

Pair this with the fact that there are several factors that affect BAC results – some of them valid, some not – and it becomes incredibly important to know how blood-alcohol level works and what you can do to impact your BAC.

The following factors can affect your BAC:

Body Composition

Before we talk about alcohol consumption, it’s important to know that everybody will react differently when they consume alcohol, and no similar set of factors will result in the same BAC for two people. The following physical factors may have an impact on how one standard alcoholic drink affects your BAC:

What Is BAC and How Does It Affect a DWI in Texas
  • Your gender
  • The amount of body fat versus muscle tissue in your body and the water level of your cells
  • Your overall build
  • Your typical metabolic rate (the rate at which your body turns food into energy)
  • The amount and type of food in your stomach before you began drinking
  • The amount of stress you are under and your emotional state
  • Whether you are diabetic
  • Your age

In other words, just because you and a buddy both had two beers, that does not mean your BAC will be the same. Legally speaking, he might be fine while you are not – or vice versa.

The Total Amount You Have Had to Drink

This is an obvious factor, but the more you drink, the higher your blood alcohol content will be. Those who drink quickly will consume more alcohol per hour, which will increase their BAC overall. Also, if you prefer drinks with higher alcohol content, your BAC will be higher than someone drinking the same portion of a beverage with a lower alcohol content.

If you are going out for the night and plan to drive home, it’s wise to stop drinking after an early beer or two to ensure you are safe on the way home. Of course, skipping booze altogether when you know you will be driving is even safer and recommended in case you must head home early.

Carbonated beverages may also skew BAC test results since carbonation can increase how fast alcohol passes through your stomach. This could lead to a higher-than-expected BAC test result.

If you are going to drink and drive, though, you should understand what counts as a standard drink before you go out. If you have a glass of beer and then fill that glass with a vodka soda, you will most likely have consumed more than two standard drinks. 

How Much Time Has Passed Since Your Last Drink

It takes time for your body to process alcohol and decrease the concentration amount in your blood. In general, it takes one hour to process a standard drink. That is just a general guideline, though. If you chug four drinks in an hour, it could take longer than four hours to get the alcohol completely out of your system.

Essentially, once the liver is tasked with processing at least one drink, it becomes overwhelmed. For this reason, it is best to wait at least an hour or two between finishing a drink and hitting the road.

Were There Any Medications in Your Bloodstream?

In general, it is not a good idea to mix medication and alcohol. A simple ibuprofen like Tylenol can spike your BAC higher than it would normally be without any medication. One simple headache tablet could mean the difference between driving away without any charges and spending a few days in jail for DWI.

There Could Be Hidden Alcohol in Your System

This is where the question of truth and justice comes in. There are lots of ways that our body can provide test results that look as if we have consumed alcohol – even if we have not done so in a traditional way.

For example, if you swish with a mouthwash that contains alcohol, a test may show that you are way over the legal limit. Also, certain foods cooked with alcohol can cause the same issue. Those are just two ways this can happen. There are many others, and they are important to recognize so you can protect yourself against unwarranted charges. Talk to an experienced DWI attorney if you think you may fall into this category.

Legal Limit for Alcohol Intoxication

If you are ever in a situation where you want to check your BAC before you get behind the wheel, options are available. Smartphone apps exist that allow you to calculate a BAC estimate by using factors like the food and drinks in your stomach, as well as your weight. Alternatively, you could ask the bartender if there is a breathalyzer at the bar, or you could even purchase one yourself.

Importantly, you need to remember that these tools all just provide an estimated BAC. Skilled DWI attorneys have shown in court that the breath test devices used by law enforcement can be woefully inaccurate. So, taking your own estimate really is not any worse.

Also, remember that in Texas, you do not have to submit to field sobriety tests, but you do have to submit to chemical tests if you are arrested. Also, if you refuse to take field sobriety tests, you will face other repercussions, including the loss of your driving privileges. 

When You Face a DWI Charge in Texas Based on a BAC Test Result, Talk to a Knowledgeable DWI Lawyer to Protect Your Rights

Driving while intoxicated in Texas affects hundreds of lives each year—and those are just the numbers for our state. In the past few years, Texas law enforcement officials have experimented with different methods for reducing the number of fatalities on the road. Extra vigilance and more DWI arrests seem to be doing the trick—but are they at the expense of truth and justice?

If you have questions about factors that affect BAC results in your case, reach out to the skilled DWI team at Fulgham Hampton Criminal Defense Attorneys for answers. Call (817) 877-3030 or fill out our online contact form for more information.

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