If you are arrested for drunk driving in Nevada, the state’s “implied consent” law requires you to take an evidentiary breath test (EBT) or blood test to measure your blood alcohol content (BAC). Driving with a BAC of 0.08% or higher is an automatic DUI, even if you were not impaired.
Here are five key things to know:
- When police first pull you over on suspicion of DUI, they will ask you to take a preliminary breath test (PBT).
- The PBT results cannot come in as evidence at trial; police just use it to determine whether there is probable cause to arrest you.
- Refusing to take the PBT will result in the police officer confiscating your license and arresting you for DUI.
- If you refuse to take the EBT or blood test after your arrest, you face a 1-year driver’s license revocation and a forced blood draw.
- Potential defense to DUI charges are 1) the breathalyzer was defective, 2) your medical condition caused a false BAC result, or 3) the police mishandled the device.
In this article, our Las Vegas DUI attorneys discuss:
- 1. What are breathalyzers in Nevada DUI cases?
- 2. What is the difference between preliminary and evidentiary breath tests?
- 3. What if I refuse the breath tests?
- 4. How accurate are breath tests?
- 5. How can the results be challenged in court?
- 6. Can I be charged with DUI with no breathalyzer?
- Additional resources
1. What are breathalyzers in Nevada DUI cases?
Breathalyzers are mechanical devices that measure your blood alcohol concentration (BAC) through your breath. Police agencies such as the Nevada Highway Patrol and Las Vegas Metropolitan Police use them on drivers they suspect have an illegal BAC of 0.08% or higher.1
Unlike DUI blood tests, breath tests are largely painless and non-invasive: You blow into the breathalyzer, which then uses an internal aqueous solution of ethanol to analyze the breath and estimate your BAC.
2. What is the difference between preliminary and evidentiary breath tests?
The preliminary breath test (PBT) takes place on the road shortly after you are pulled over. The evidentiary breath test (EBT) takes place at the police booking station following your arrest. Each test is different and serves a distinct purpose:
2.1. Preliminary Breath Test (PBT)
When you are pulled over in Nevada – or when the police arrive at the scene of an accident where DUI is suspected – the police will probably ask you to do three things:
- take out your driver’s license and registration,
- perform field sobriety tests, and
- submit to a preliminary breath test (PBT).
The PBT is also called a roadside breath test or preliminary alcohol screening (PAS). It is meant to give the police officer an initial idea of whether you are under the influence of alcohol or not.
If the case goes to trial, PBT results may come in as evidence to show the police had “reasonable grounds” for arrest. Though PBT results cannot be used to show that you were driving under the influence.4
2.2. Evidentiary Breath Test (EBT)
Nevada law outlines strict rules that police must follow when administering an evidentiary breath test following your arrest. These regulations include the following:
- No more than two hours can elapse between the time of driving the motor vehicle and the breathalyzer test.
- The officer is required to observe you for at least 15 minutes prior to administering the breathalyzer test. This is to make sure you do not vomit, burp, belch, regurgitate or do anything else that can skew the breath results.
- The breath test must be administered two times right after each other, and the two BAC readings cannot differ by more than 0.02%.
- The breathalyzer needs to have been properly maintained and calibrated.
- The police officer needs to be certified to administer the breathalyzer.5
Unlike PBT results, EBT results can be used against you in court to show that your BAC was 0.08% or above.6
3. What if I refuse the breath tests?
Under Nevada law, you give “implied consent” to:
- submit to a PBT if you are suspected of DUI during a traffic stop; and
- submit to an EBT (or blood test) after you are arrested for DUI.
Nevada law imposes various consequences for refusing to take a PBT or EBT:7
|Type of Breath Test||Consequences for refusing to take a breath test|
|Preliminary breath test (PBT)|| |
|Evidentiary breath test (EBT)|| |
4. How accurate are breath tests?
Not very accurate considering so many variables unrelated to alcohol can cause false positives.
One problem stems from the manufacturer’s refusal to share the Intoxilyzer 8000’s source code. Just in the last few years, judges in
- Oklahoma, and
- even Ontario, Canada
have ruled that the Intoxilyzer 8000 cannot be trusted.9
5. How can the results be challenged in court?
Depending on the facts of your case, we will explore the following defenses when fighting your DUI charge:
|Ways to challenge breathalyzer results in Nevada DUI cases||Possible strategies|
|Procedural defenses|| |
|Environmental or mechanical defenses|| |
|Physiological defenses|| |
If we can cast doubt on the accuracy of the breath test, then the court might exclude it as evidence. Once the BAC results are excluded, the prosecution should be more willing
- to reduce the drunk driving charge to reckless driving or
- to throw it out completely.
6. Can I be charged with DUI with no breathalyzer?
Yes, you can be charged with DUI in Nevada based only on blood test results.
Even if the blood results show a legal BAC level, you could still be convicted if you were impaired. However, it is much harder for prosecutors to prove DUI without a failing breath- or blood test.
For more information about Nevada DUI laws, refer to our related articles:
- Nevada DUI: Should I choose a breath test or a blood test? – a side-by-side comparison of the pros and cons of each chemical test
- The court process in Nevada DUI cases – a step-by-step look at how drunk/drugged driving cases proceed through criminal court
- Top 20 defenses to a Las Vegas Nevada DUI charge – overview of the most common ways to fight DUI charges
- I was suffering from hypoglycemia when I was arrested for DUI in Nevada. Can I use this to fight the charges? – a deep-drive into how diabetes can affect breath test results
- Do I have to admit that I’ve been drinking if I’m pulled over for DUI in Nevada? – a discussion of how you should be polite to police but not answer any questions
- NRS 484C.110. See, for example: Field v. Department of Motor Vehicles & Pub. Safety (1995) 111 Nev. 552; State v. Eighth Judicial Dist. Court. (2021) 479 P.3d 1004. Breathalyzers usually employ infrared spectroscopy and/or fuel cell technology. The devices convert the quantity of alcohol in your breath to the quantity in your blood. This conversion often causes compromised results and inaccurate readings.
- See, for example, Intoxilyzer 8000 Reference Guide, Florida Department of Law Enforcement Alcohol Testing Program (2006). It is manufactured by CMI, Inc., in Owensboro, Kentucky. It was approved for use in Nevada by the Nevada Committee for Testing on Intoxication. The Intoxilyzer 8000 uses a two-filter wheel infrared (IR) spectrometer to detect organic vapors in a breath sample. Although it takes about 20 minutes to warm up, the device has a “standby” mode that permits it to run continuously without depleting its resources. Unlike previous models which had a pressure switch, the Intoxilyzer 8000 uses a flow sensor. In order for the flow sensor to work, the following four conditions must be met: 1) You blow no less than 1.1 liters of air into the tube; 2) You blow continuously for no less than one (1) second; 3) The alcohol concentration slope starts to plateau; and 4) The pressure reaches about 50 psi. Finally, the blood alcohol level results get printed on paper.
- Same. Note that Intoxilyzer breath testing machines are typically kept at police stations or detention facilities. Though police can bring traveling units to the scene of a suspected DUI. The machine uses the “Dry Gas Standard” to conduct control tests during the breath test sequence. The correct gas concentration is 0.08 g/210L with an acceptable range from 0.075 to 0.085 g/210L. When any analysis result falls outside of the acceptable range, the machine displays CONTROL OUTSIDE TOLERANCE.
- NRS 484C.150. Implied consent to preliminary test of person’s breath; effect of failure to submit to test; use of results of test. See also State v. Sample (2018) 134 Nev., Advance Opinion 25 (“Because the PBT was not administered pursuant to a warrant or an exception to the warrant requirement, we conclude that the district court properly suppressed the PBT evidence as an unconstitutional search.”). Note that if the police arrest you prior to giving the PBT, the police may not then give you a PBT without your consent to take it or without a warrant (or valid warrant exception). Otherwise, the PBT may qualify as an unlawful police search.
- NAC 484C.100–.120; NRS 484C.200; see Nevada DUI Prosecution Manual (2014).
- NRS 484C.160. Implied consent to evidentiary test
- NRS 484C.150; NRS 484C.160; NRS 484C.240.
- NRS 484C.160. If you are arrested for drunk driving in Nevada, you can usually elect to take a blood test instead of a breath test. Since taking blood samples is a more complicated procedure than using a breathalyzer, you must pay for all associated costs if a working breathalyzer was readily available, and you are ultimately convicted of DUI. Note that if police believe you are under the influence of drugs, you must take a chemical test for blood because breathalyzers cannot detect drugs. Then if your results come back positive for DUI, the Nevada Department of Motor Vehicles will mail you a letter notifying you that they will revoke your license.
- Sean Lavin, Breath tests banned from courtrooms in DUI cases, ClickOrlando.com (July 31, 2014); Dan Karpenchuk, Ontario court finds common breathalyzer inaccurate, opening legal can of worms, WBFO 88.7 (May 17, 2016); Krystle Sherrell, Breathalyzer Tests Dismissed As Evidence In Oklahoma DUI Cases, KFSM 5 News (September 28, 2016).