"Blood Alcohol Content" (BAC) in Nevada DUI Cases

Nevada DUI laws
make it a crime to drive with a .08% or higher BAC, which is short for "blood alcohol content." The threshold is even lower for commercial drivers and drivers under 21 years of age. 

Drivers in Nevada

Legal BAC threshold*

Non-commercial drivers age 21 and older

Under .08%

Commercial drivers

Under .04%

Drivers under 21 years old

Under .02%

*Driving while impaired by alcohol is illegal even if the driver's BAC is within legal limits.

Drivers arrested for DUI can elect to take a breath test or a blood test to measure their BAC. If the driver refuses both, the cop can get a warrant to forcibly administer a blood test.

Sometimes police wrongly arrest people for driving under the influence and miscalculate their blood alcohol content. Many factors can falsely influence test results, including:

  • rising blood alcohol,
  • medical conditions, and/or
  • faulty testing equipment

In this article, our Las Vegas DUI defense attorneys answer frequently-asked-questions about BAC in Nevada drunk driving cases, including testing methods, the consequences for refusing a chemical test, and drugged driving. Click on a topic to jump to that section:

motorist taking a roadside breath test to measure BAC
Driving with a BAC of .08% is illegal in Nevada.

1. What is BAC in Nevada DUI law?

BAC stands for blood alcohol content. This also goes by "blood alcohol concentration" or "blood alcohol level." In short, BAC is the quantity of alcohol in the driver's blood. Therefore, a person's level increases the more alcohol he/she drinks.  

Specifically, a BAC is the number of grams of alcohol per 100 milliliters of blood or 210 liters of breath. These are expressed as a percentage. In Nevada, it is a DUI to drive with a BAC of .08% or higher.

Note that commercial drivers commit DUI if their BAC is .04% or higher. Learn more about Nevada commercial DUI laws. Also note that drivers under 21 commit DUI if their BAC is .02% or higher. Learn more about Nevada underage DUI laws.1

2. How is blood alcohol content measured?

Blood tests or breath tests. Drivers arrested for driving under the influence of alcohol in Nevada may choose which test to take:

2.1. Nevada DUI blood tests

Blood tests are the most reliable method for determining BAC because they involve actually testing the blood itself. Like it sounds, DUI blood tests require a phlebotomist drawing a blood sample from the driver's vein (usually in the arm) and sending it to a lab. In Nevada, it takes several weeks to get the test results. 

2.2. Nevada DUI breath tests

Breath tests are the most convenient method of measuring BAC because they are quick and non-invasive. The suspect simply breathes into a small machine called a Breathalyzer that analyzes the person's alveolar (deep lung) air. Breath testing machines in Nevada calculate these numbers immediately.2

3. How accurate are DUI blood and breath tests?

It depends on the situation, but there are many reasons why BAC results may be plain wrong in Nevada DUI cases. 

3.1. False Nevada DUI blood tests

Many factors can cause DUI blood tests to return inaccurate results, including: 

  • improper procedures for taking the blood,
  • improper procedures for storing the blood,
  • contamination of the blood,
  • insufficient amounts of anticoagulant and preservatives in the blood vial, or
  • procuring the blood sample too long after the alleged DUI incident
A DUI blood test being administered
Blood tests render more accurate BAC results than breath tests in Nevada DUI cases.

Even such factors as the phlebotomist having an expired license can cast doubt on the accuracy of the test results in Nevada DUI cases. North Las Vegas criminal defense attorney Michael Becker illustrates this concept:

Example: Ben chooses to take a blood test after getting arrested for DUI in Las Vegas. The BAC result is .15%. While Ben's defense attorney is investigating the case, he discovers that the phlebotomist who took the blood let his license lapse a year ago. He informs the Clark County District Attorney, who then agrees to reduce the DUI charge to the Nevada crime of reckless driving

In the above example, it is likely that the BAC was in fact .15% despite the tester's lapsed license. And if the case went to trial, it is possible that Ben could still be found guilty of driving while inebriated based on other evidence. However, the defense attorney was able to use the phlebotomist's mistake to Ben's advantage; he negotiated a favorable solution that resulted in lessened charges without the uncertainty, time, and expense of going to trial. 

Note that it may be possible to get blood draws independently tested in Nevada DUI cases.

3.2. False Nevada DUI breath tests

BAC numbers calculated from breathalyzers are already less reliable than blood test results. Other situations that can cause inaccurate breath tests include:

  • mouth alcohol taking the place of deep lung air,
  • inconsistent breathing pattern, 
  • outside interference from RFI (radio frequency interference), temperatures, or other causes that hinder the breathalyzer's circuitry and utility,
  • various medications, or
  • various medical conditions such as GERD or diabetes (read more about diabetes as a Nevada DUI defense)

Even burping prior to a breath test can cause inaccurate BAC results in Nevada DUI cases.

4. How long does it take to get test results after a DUI arrest?

Breath test results are available immediately. Blood test results often take weeks to come back. 

5. Does a BAC of .08% or higher mean a person is intoxicated?

No. Many drivers hold their alcohol well and can drive safely with high blood alcohol levels. However, Nevada law makes it a crime to drive with a BAC of .08% or higher even if the person is not impaired by the alcohol.3

Note that blood alcohol level is influenced by such variables as: 

  • weight,
  • gender,
  • whether the person has eaten or has an empty stomach,
  • whether the person is ill or on certain medications,
  • how long the person was drinking, and
  • the type of alcohol consumed

Consequently, different people who drink the same amount of alcohol may show two totally different results.

Also, note that the way a person's liver metabolizes alcohol may cause a person's BAC to rise for up to two (2) hours even if he/she has stopped drinking. This is called "rising blood alcohol," and it can cause a breath or blood test result to be higher than the person's actual level at the time he/she was driving. Therefore, a BAC test result of .08% or higher does not necessarily mean that the person did not have lower, legal BAC level when he/she was behind the wheel.

6. Does having a BAC below .08% mean that the driver is not guilty of DUI?

No. Driving under the influence of alcohol is always a crime no matter what the blood alcohol content is. So a person may be convicted of DUI for driving while impaired by alcohol even if his/her level is lower than .08%. These cases often involve people who are not used to drinking or who have a very slight physical frame. North Las Vegas criminal defense attorney Neil Shouse gives an example:

Example: Addalee is driving home from a charity luncheon at the Venetian, where she had a glass of champagne. Addalee never drinks and weighs only 100 pounds, so she gets intoxicated quicker than her friends. A Las Vegas Metropolitan Police Department cop notices her car failing to maintain a lane and pulls her over. After Addalee fails the Nevada field sobriety tests, the cop arrests her and books her at the Clark County Detention Center. There the cop administers a breath test, which returns a BAC of only .06%. 

In the above example, Addalee can still be convicted of DUI in Nevada because the champagne compromised her ability to drive safely. Driving under the influence is still against the law even with a level of less than .08%.

7. If I am arrested for DUI, should I take the breath test or blood test?

Each test has its pros and cons...

  • Breath tests are painless and non-invasive, whereas blood tests are painful and invasive;
  • Breath tests are quick, whereas blood tests take several minutes, especially if the phlebotomist has trouble finding a workable vein;
  • Breath tests return immediate results, whereas blood test results take several weeks;
  • Breath tests results are not as accurate as blood tests results; and
  • Breath tests cannot be retested by an independent lab, whereas a defense attorney can request that blood be retested. 
a cocktail next to a car key
BAC numbers measure only alcohol, not drugs.

Another difference concerns driver license suspension, which is a penalty of getting arrested for DUI. When a DUI arrestee takes a breath test, the police officer will immediately confiscate the person's driver's license. But when a DUI arrestee instead takes a blood test, the suspension does not begin until the blood results come back positive for DUI. 

Note that when a driver gets her/his license suspended, they are given a temporary seven (7) day license and the opportunity to contest the suspension at a Nevada DMV hearing. Also note that the length of the driver license suspension depends on the driver's prior DUI history:

Learn more about Nevada DUI penalties.4

8. What if a driver is under the influence of drugs instead of alcohol?

When a cop suspects that a driver is under the influence of a controlled substance or other drugs, the driver is obligated to submit to a blood test. (If the driver refuses, the cop can get a warrant to take the blood test.) And this blood test will test for various narcotics and drugs instead of BAC.

9. Can I refuse to take a test if I get stopped for DUI?

If the driver refuses to submit to a breath or blood test, the police officer can ask a judge for a warrant to force the driver to submit to a blood test...

The Nevada DMV will also revoke the person's license for at least one (1) year. Note this revocation is extended to three (3) years if the person already had his/her license revoked due to refusing an evidentiary test in the last seven (7) years...

Finally, the prosecutor can also use the refusal as evidence against the defendant if the DUI case goes to trial.

Arrested for DUI in Nevada? We are here for you...

If you or loved one has been charged with a "DUI" in Las Vegas, throughout Clark County, or elsewhere in Nevada, call our Las Vegas criminal defense attorneys at 702-DEFENSE (702-333-3673). We can provide a free consultation in the office or over the phone. Depending on the case, we may be able to get the DUI charge reduced or even dismissed so your record stays clean. 

For information about California BAC laws, read our article on California BAC laws

 Legal References:

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