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What Is the Difference Between a
Breath Test and a Blood Test?

Under The Influence of Alcohol?

PA DUI attorney

If a police officer pulls you over on suspicion that you might be under the influence of alcohol, he or she will want to test your blood alcohol concentration. In Pennsylvania, your BAC can be used to determine the level of penalties you might face if you are convicted of a DUI. An officer might ask you to submit to chemical testing to obtain sufficient evidence of intoxication to convict you. You might be asked to submit to chemical testing if the officer suspects you have been drinking through the observations he or she has made of your driving, your appearance, and any scent of alcohol that might be on your breath. If the officer asks you to take a portable breath test at the side of the road, you can politely refuse. However, if you are placed under arrest, you cannot refuse a breathalyzer or blood test without facing a mandatory driver’s license suspension and the highest penalty level for DUIs.

If you refuse to submit to chemical testing after being arrested for a DUI, your driving privileges will be automatically suspended for 12 months by the Pennsylvania Department of Transportation. If you are later convicted of a DUI, this suspension will run consecutively to the suspension period for your DUI conviction. People who refuse to submit to chemical tests also face the highest penalties for DUIs even if their actual BACs may have been lower at the time of their arrests. In most cases, it is best for you to submit to chemical testing. At the time of your arrest, you should be told by the officer that you can choose to take a blood test instead of a breathalyzer test. Here is some information about these tests from DiCindio Law that might help you to make your decision.

Breathalyzer Vs. A Blood Test

A breathalyzer test is a test that is performed at the police station or jail. In this test, you will be asked to blow into a tube that is attached to a machine. The machine analyzes your breath sample to test for alcohol molecules and produces a reading of your BAC.

A blood test involves submitting to a blood draw. This may be performed at a hospital by a phlebotomist. Once your sample is drawn, it will be given to the officer and taken back to the police station. The sample should be refrigerated and then transported to the crime lab for analysis.

Police officers do not need to get search warrants to get a breath sample on a breathalyzer machine. However, the U.S. Supreme Court has held that police officers must get warrants before they take blood samples since the process is more invasive.

Accuracy Of Breath Vs. Blood Tests

When you take a breathalyzer test, it measures how much alcohol is contained in your breath instead of your blood. Your BAC is then calculated from this measurement. The alcohol on your breath is proportional to the alcohol in your blood because of the oxidation process that occurs as your body metabolizes alcohol. However, breathalyzer tests are more likely to contain errors caused by issues with the machines and the administration process. Blood tests directly measure the amount of alcohol in your blood. While errors can occur because of problems in the vials, storage,

transportation, and lab processes, they are generally more accurate than breathalyzer tests.

False Results

Breathalyzer machines must undergo regular maintenance and be calibrated correctly to provide accurate readings. The officers who administer the tests must also follow specific protocols during the administration. For example, you should be asked about certain medical conditions. If you belch or hiccup, the officer should wait for 20 minutes before administering the test. You also should not be administered the test if you have gum in your mouth. All of these things can cause your breath test to read higher than it otherwise might. If you know that you have not been drinking and do not have any illegal drugs or non-prescribed medications in your bloodstream, you might want to ask for a blood test instead. While breathalyzer tests sometimes produce false positives, blood tests are more accurate as long as they are administered correctly and the samples are stored and transported properly.

Even though trained professionals draw blood and scientific measurements are used, blood tests can still result in erroneous readings. The most accurate test will be taken immediately after your arrest. If you were drinking right before your arrest, your BAC will continue to rise after your arrest if the alcohol has not already completely entered your bloodstream.

Rate Of Absorption Of Alcohol

The rate that your body absorbs alcohol is important. When you swallow an alcoholic drink, the alcohol does not immediately enter your blood. It first needs to be processed before it is absorbed into your bloodstream. 

Because of the absorption rate, alcohol will be detected at different rates depending on several factors, including the following:

  • When you last drank
  • Whether your stomach is full or empty
  • Number of drinks
  • How fast you drank
  • Your weight and gender

If alcohol is present in your stomach but not in your bloodstream at the time of your stop and arrest, it may have entered your bloodstream once you get to the police station for a test. This means that your test might not accurately reflect your BAC at the time of driving.

If you are on a ketogenic diet or are diabetic, your body can produce ketones that can increase your BAC during a blood test. If either of these situations applies to you, you should talk to an experienced PA DUI attorney for help.

How To Find A DUI Attorney Near Me

If you believe that your BAC was not accurate, getting help from an experienced DUI attorney is important. Michael DiCindio at DiCindio Law knows how to challenge breathalyzer and blood tests. He understands the procedures that must be followed and the maintenance and calibration standards for breathalyzer machines. Contact our office today at 610.430.3535.

If you or a loved one has been charged with a crime in Pennsylvania, contact Mike DiCindio, Esq today at 610.220.4691!

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