Updated on July 14th, 2023 at 03:43 pm

What Breath Alcohol Tests Are Used in VA?

The breath alcohol test in Virginia is the most common chemical testing done for a DUI case in this state. The breath alcohol breath test requires you to blow into a machine that measures your breath alcohol content (BAC). But how many types of this test exist?

There are two types of breath alcohol breath tests given in Virginia – the portable breath test (PBT) and the evidentiary breath test, which are done on the street and at the police station, respectively. There’s also a third; the ignition interlock test that’s installed in motor vehicles, and drivers convicted of DUI have to test their BAC levels before they can drive. 

If you take either of the first two tests, you need a Harrisonburg DUI lawyer who understands the science behind the machines used and knows how to challenge the validity of the BAC results in your case.

What is a PBT Alcohol Test, VA?

A preliminary breath test in Virginia is a roadside breath test that drivers submit as part of a field sobriety test to determine their blood alcohol levels. The test is conducted to determine probable cause for an arrest. As such, if the BAC reading is higher than the legal 0.08%, they are arrested for DUI.

Unfortunately, these are the most unreliable of the two blood alcohol breath tests. The exact blood alcohol content levels these preliminary breath tests provide are often not admissible in court but may be admissible if your attorney challenges the probable cause the police officer had to arrest you for a DUI. Their propensity to fault is because the PBT machines do not have the same filters the evidentiary machines have.

They are also highly susceptible to weather temperatures and other factors that affect the reliability of these alcohol screening devices. Refusing to give a breath sample for a PBT does not violate Virginia’s Implied Consent law.

What is an Evidentiary Alcohol Breath Test, VA?

An evidentiary alcohol breath test is a test that measures the amount of alcohol in the breath sample you provide. The device uses this measurement to estimate your blood alcohol content. Unlike PBTs, drivers submit to evidentiary tests at the police station.

There has been a lot of litigation across the nation about the reliability of these machines. There are a number of factors that affect the reliability of the results these machines produce, but courts – while acknowledging there are problems with the machines – have made it the duty of your defense attorney to prove the machine malfunctioned in your particular case.

Unlike PBT tests, unreasonable refusal of evidentiary alcohol breath tests at the station can result in refusal charges. Consequences of refusal may include license suspension.

How common is a false breathalyzer reading?

Breathalyzer tests give accurate BAC results only 40% of the time. Even worse, the machines have a margin of error between 0.005% and 0.02% in their readings.

Several things could cause false positives, including medication and certain foods spike BAC levels above the legal limit. DUI suspects in Virginia can fight DUI charges by submitting evidence proving false breathalyzer results and that he wasn’t drunk during the test.

Personal hygiene products

Some personal hygiene products contain alcohol as an ingredient. These include:

  • Mouthwash
  • Breath sprays
  • Colognes and perfumes
  • Toothpaste
  • Aftershave
  • Hand sanitizers

These products may produce false positive breath test results since breathalyzers test alcohol fumes. The alcohol fumes from these products (even when on the skin) can trigger a false positive.

Certain foods

Foods that contain alcohol and high levels of yeast can cause a false positive. Yeast in foods ferments and converts sugar into alcohol, and this process is responsible for the trace amounts of alcohol in baked foods.

Other foods include:

  • Ripe fruits
  • Hot sauces
  • Protein bars
  • Fermented sodas
  • Energy drinks
  • Non-alcoholic wine and beer

Medical conditions and medications

Medical conditions like GERD and diabetes can cause false positives. Medication, including allergy pills, and cough syrups, can also trigger false positive breath test results.

Note: We should mention that residual alcohol in the mouth from foods, and medication dissipates within 20 minutes. With the 20-minute time frame required before the breath alcohol technician takes an official breath sample, scenarios of false positives are reduced.

Our defense lawyers in Harrisonburg will guide you on when a false positive breath test result is a viable defense.

How long can alcohol be detected in a DUI breath test?

How long a breathalyzer can detect alcohol levels from your breath depends on the individual. For some, the breathalyzer can detect alcohol levels for 12 hours, while in others, it can detect alcohol levels even 24 hours later.

An average person breaks down one alcoholic drink in an hour. This rate differs from person to person depending on age, height, weight, sex, and body fat percentage. Other people metabolize alcohol far slower, so they have alcohol breath for longer. Generally, females break down alcohol slower than males, so they have alcohol in their system for longer.

Can I call my attorney before taking a breathalyzer test?

The decision to submit or not to submit to a breath test is important. As such, some people think they can consult with their lawyer before deciding. Unfortunately, this isn’t true.

By the time you get to call your attorney, you might have already made a decision. There are no repercussions for refusing to take the PBT but refusing the evidentiary breath test can make you look guilty and be used as evidence against you in court.

Harrisonburg DUI Lawyer 

Both of these machines fail to take into account several factors that would determine your actual blood alcohol concentration, including, but not limited to, your gender, your lung capacity, and various medical conditions.

Whether you take the PBT or the evidentiary blood alcohol breath test is your choice. There are consequences for refusing the evidentiary blood alcohol breath test that may include a longer license suspension.

Refusing the test does not guarantee you will not be convicted but may help you avoid certain penalties if your BAC is .15 or higher. Contact Harrisonburg DUI Attorney at Keefer Law Firm for a free, confidential case review before taking a breath test.

To schedule your free consultation with our Harrisonburg DUI lawyer, you can reach us at (540) 433-6906.

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When You Need a Traffic Lawyer,

Keefer Law Firm Can Help.

  1. Attorney Keefer is one of the few people in Virginia to call himself a NHTSA Certified Field Sobriety Instructor.
  2. He has completed the DOT Certified Breath Technician course on the EC/IR II, Virginia’s breath tester for evidence.
  3. He was a founding member of the DUI Defense Lawyers Association and is a member of the National College for DUI Defense.
  4. Attorney Keefer has more than 30 years of experience providing legal representation throughout Virginia.
  5. Our office contains the Alco-Sensor III, which is also used by law enforcement for preliminary breath testing.
  6. We offer free consultations for traffic offense and DUI cases.