A breathalyzer, or breath alcohol test, can be administered by law enforcement officers to determine whether a driver has consumed alcohol. Drivers who refuse, in most states, can be at risk of a driver’s license suspension. Exactly how long does alcohol stay on your breath?

When Can an Officer Give a Breathalyzer?

Officers usually give breathalyzer tests in three scenarios: (1) traffic accidents with injury; (2) traffic stops; and (3) checkpoints. Laws in many states require breathalyzer tests of all drivers involved in accidents with injuries. 

At checkpoints and traffic stops, officers evaluate a driver’s sobriety using tools like:

  • Roadside sobriety tests
  • Breathalyzer tests
  • Blood tests

DUI urine tests are administered under certain circumstances. In the urine, alcohol can be detected for 12-24 hours after the last drink was consumed. 

Non-invasive procedures, such as urine and breathalyzer tests, can be administered at the officer’s discretion. For a blood test, however, a judge must authorize by signing a warrant. 

Before giving a breathalyzer test or asking a judge for a warrant to give a blood test, an officer has to develop specific, articulable facts that demonstrate the driver’s condition. 

A driver may be under the influence of alcohol if the officer observes: 

  • Red or flushed skin
  • Glassy or bloodshot eyes
  • Loud talking 
  • Slurred speech

To develop a reasonable suspicion that the driver is operating a vehicle under the influence of alcohol, officers do not even need to smell alcohol on a driver’s breath.

How Do Officers Determine Sobriety?

At sobriety checkpoints and during traffic stops, officers have discretion in the use of sobriety evaluation methods. Depending on the officer’s judgment, they may choose to use a method that has not been scientifically evaluated for validity. 

An experienced DUI lawyer may be able to get your test results thrown out if an officer used an invalid or questionable method to evaluate your sobriety. 

Field Sobriety Tests

To establish probable cause for arrest, officers conduct field sobriety tests. The National Highway Traffic Safety Administration (NHTSA) established the validity of a battery of tests including:

  • Horizontal Gaze Nystagmus test
  • Walk-and-Turn test
  • One-Leg Stand test

Even though the NHTSA validated the accuracy of these tests, their use has been criticized by disability advocacy groups. 

Unfortunately, some officers use sobriety tests that have not been validated by the NHTSA. Field sobriety tests with questionable validity include: 

  • Finger-to-Nose test
  • Alphabet test
  • Counting backward test

Other tests that have not been validated by the NHTSA include counting fingers while touching the finger of the opposite hand and standing with feet together, head back, and eyes closed. 


A breathalyzer detects the presence of ethanol in the lungs. Ethanol, the scientific term for alcohol, is water-soluble. Since it is water-soluble, it can travel throughout the water spaces in our bodies, like our bloodstream. 

The body first absorbs alcohol through the stomach within minutes after the first sip. 

From the stomach, here’s how alcohol gets to the lungs:

  • Ethanol molecules are absorbed into the inside lining of the stomach and intestine
  • Ethanol molecules travel through the membranes
  • Outside of the gut cells, ethanol molecules pass into tiny blood vessels in the gut

After entering the bloodstream in liquid form, ethanol travels through the circulatory system to the lungs. 

In the lungs, ethanol is vaporized into a gas. This gas can be detected by the breathalyzer. For 12-24 hours after the last drink is consumed, alcohol can be detected on the breath. 

The factors that influence how long alcohol stays on the breath include:

  • Age
  • Weight
  • Gender
  • Amount of alcohol consumed
  • Period of time over which alcohol was consumed

No one knows their metabolism well enough to estimate how long alcohol stays in their bloodstream. Never risk driving drunk. Even if you think you can manage driving after a few drinks, any time you drive drunk it can lead to your first DUI

Blood Tests

Sometimes, drivers refuse breathalyzers. For multiple-offense drivers, another DUI may mean a felony DUI charge, so a breathalyzer test may be tempting to refuse. But an officer can often get a warrant from a judge to have a driver submit to a blood test. For up to six (6) hours after the last drink is consumed, alcohol can be detected in the bloodstream. 

Contact the Indianapolis DUI Defense Attorneys at Suhre & Associates DUI and Criminal Defense Lawyers For Help Today

For more information, contact the Indianapolis DUI defense Attorneys at Suhre & Associates DUI and Criminal Defense Lawyers give us a call today at (317) 759-2599 or visit us at our Indiana law office.

Suhre & Associates DUI and Criminal Defense Lawyers – Indianapolis
101 W Ohio St #2000

Indianapolis, In 46204

United States