What Is a Breathalyzer Test?

Law enforcement officer administering a breathalyzer test.

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If a person is pulled over for suspicion of driving while intoxicated, they will likely be asked to take a sobriety test. This usually involves a breathalyzer test, but other types of sobriety tests include saliva tests, blood tests, or urine tests. Breathalyzer tests are frequently used because they are fast and non-invasive.

This article explores how breathalyzer tests work and what happens if a person refuses to take one.

What Is a Breathalyzer Test?

When alcohol is consumed, it enters the stomach and small intestine, where it is absorbed and carried through the blood other parts of the body, including the brain and lungs. Because of this, alcohol is exhaled when people breathe.

A breathalyzer test, also known as a breath test, measures blood alcohol concentration (BAC) levels based on the amount of ethanol detected in the air expelled from the lungs.

These devices look similar to a handheld walkie-talkie or mobile phone. They are administered by having the driver blow into a disposable mouthpiece. 

The test may be administered more than once to ensure that the results are accurate. Failing a test, which means showing a BAC result over 0.8%, will result in arrest.

When Breathalyzer Tests Are Used

As blood alcohol concentrations rise, a person's level of impairment increases. In all states, it is illegal for people to operate a vehicle with a BAC level over 0.08%. In the state of Utah, the legal limit is 0.05%. And in all states, it is illegal for anyone under the age of 21 to drive with any level of alcohol in their blood.

If you are involved in an accident or are pulled over for speeding or because law enforcement suspect you have been drinking, you may be asked to take a breathalyzer test. This test can determine if you have been drinking and how high your BAC levels are. 

While manual and electronic tests are available, police typically use an electronic device. 

Passengers may also sometimes be asked to take a breathalyzer test. This may happen if the individual is under 21, is on probabion for a previous DUI or aother offense that includes a no-alcohol provision, or if the officer suspects that the passenger was the one who was actually operating the vehicle.

Breathalyzer Laws and Policies

Law regarding the use of breathalyzer tests can vary by state. Regardless of where you are, if your BAC is over the legal limit, you may be arrested and charged with driving under the influence.

Implied Consent

It is important to note that driving is not a legal right but a privilege. That privilege is granted by the state where you live after you meet certain conditions, such as passing a written and/or driving test.

You are also not granted the privilege to operate a motor vehicle unless you agree to abide by certain regulations and conditions. In all 50 states, those conditions include something called "implied consent." Whenever you apply for a license or renew your driver's license, you must sign an agreement promising to abide by the implied consent laws of your state.

Typically, most states implied consent laws include:

  • Carrying a driver’s license and proof of insurance and producing them when asked by law enforcement.
  • Consenting to blood, urine, saliva, and/or breath tests to determine your blood-alcohol content if asked.
  • Performing field sobriety tests when requested.

In some states, the implied consent terms are printed on the back of your driver's license itself.

No Refusal

In the crackdown on drunk driving, some states have now developed "no refusal" strategies, in which they can obtain immediate search warrants to obtain blood samples from drivers who refuse to take breathalyzer tests.

During targeted periods, usually around holiday weekends, judges remain on-call to issue search warrants on the spot to streamline the due process procedures. The result has been more guilty pleas and fewer DUI trials.

Consequences of Refusing a Breathalyzer Test

Regardless of the implied consent laws in your home state, you are subject to those in the state in which you are driving. Even though you agreed to abide by these conditions when you applied for a driver's license, you can still refuse to take the sobriety tests.

However, in every state, refusing to submit to such testing is itself a violation that carries penalties, regardless of whether you are convicted of drunk driving or not. In 10 states, refusal to submit to testing can result in criminal penalties and civil ones.

The 2016 Supreme Court decision of Birchfield v. North Dakota allows people to refuse warrantless blood tests without being criminally punished since blood tests can be considered invasive. However, refusing to submit to a breath test can still be punished.

Immediate Suspension of License

In most states, the officer can immediately confiscate your driver's license as an administrative, not criminal action, because you broke your written promise to submit to such testing when you applied for that license.

You may be thinking that is a violation of your right against double jeopardy and being punished for the same crime twice. But in most states, taking away your driving privileges has been set up as an administrative function of the Department of motor vehicles and not a function of the criminal court.

Because it is the Department of Motor Vehicles that grants driving privileges, the DMV also has the power to take them away.

If you refuse the officer's request for sobriety testing, your license can be immediately suspended for 90 days up to two years, depending on the laws of the state in which you are arrested. You may also have to pay fees and penalties before your license can be returned.

Cause for Arrest

It's the job of our law enforcement officers to keep the roads safe for everyone. If the officer believes that you are intoxicated and a danger to yourself and the public, they can arrest you just because you refused to take the tests.

Increased Fines and Penalties

In all states, if you refuse to be tested, the penalties will be more severe if you are eventually convicted than they would have been if you had submitted to the tests in the first place.

Refusing to take a test will not eliminate evidence of guilt. Courts will convict drivers of driving under the influence based on the officer's observations before pulling them over and during the arrest. The officer's statements that they smelled alcohol or that you were slurring your words or unsteady on your feet can all be considered evidence.

Most police vehicles today are equipped with dash cams, which means that video of an arrest may also be available as evidence.

Admission of Guilt

In some jurisdictions, the fact that you refused to take the requested tests is itself evidence of your guilt. Your refusal to submit to blood-alcohol concentration testing is seen in some states as an admission of guilt that can be used against you at trial.


The bottom line is that refusing to take the sobriety tests will cost more in the long run, including larger fines and fees, longer license suspension, and possibly longer jail time if it's not your first offense. If you are stopped, your best bet is to take the tests.

Frequently Asked Questions

  • If you refuse to take a breathalyzer test, how long is your license suspended?

    Refusing to take a breathalyzer test can result in your license being suspended for 90 days and for as long as two years. Specific timelines vary depending on state laws.

  • When can you refuse a breathalyzer test?

    You have the right to refuse a breathalyzer test, but it comes with a cost. In addition to immediate suspension of your driving license, in some states, you may be charged for refusal to take the test, and you can still be convicted of a DUI even without taking a breathalyzer. In some states, you may also be required to install an interlock device on your car for up to a year if you refuse a breathalyzer test.

6 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Conference of State Legislatures. Traffic safety trends: State legislative action 2019.

  2. Birchfield v. North Dakota. No. 14-1468. Supreme Court of the United States. 2016.

  3. Foundation for Advancing Alcohol Responsibility. Improving DUI system efficiency: A guide to implementing electronic warrants.

  4. Foundation for Advancing Alcohol Responsibility. National drunk driving statistics map.

  5. National Conference of State Legislatures. Criminal or enhanced civil penalties for implied consent breath test refusal.

  6. Youngentob K. Changing lanes: the criminalization of refusal in DUI laws. Vand L Rev. 2017;70:121.

By Buddy T
Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism.