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How a Breath Test Can Impact Your Texas DWI Case

When you are pulled over and suspected of driving while intoxicated (DWI), an officer will likely ask that you submit to a breath test. You may refuse or you may not. If you are arrested, you will be tested again once you are at the police station. Breath tests are a scary thing, and people automatically assume that breath tests don't lie.

But they do.

You just need an experienced attorney who can determine when the breath test is inaccurate or the results may not be reliable so that admissibility can be challenged. Carl David Ceder, an aggressive DWI defense attorney based in Plano but representing clients throughout the Dallas and Fort Worth, Texas, metro area, understands how these tests work and don't work. 

Remember, each case is different, and so there shouldn't be an assumption that each breath test can be successfully challenged. You should, however, know that in many cases they can, and an experienced DWI criminal defense attorney like Carl Ceder can make that determination. Your DWI case can turn in your favor based on that determination, too. Here's what you should know about breath tests and DWI cases in Texas.

The Difference Between a Preliminary (Portable) and Non-Portable Breath Tests

When you are initially pulled over for a traffic stop and the officer suspects that you are unlawfully intoxicated behind the wheel, he may ask you to submit to a breath test. The test used on-site is a preliminary breath test (PBT). This test is different from the breath test you'll be asked to take – if arrested – once you are at the police station.

Preliminary Breath Test

A preliminary breath test is a small portable breathalyzer. Officers keep them in their vehicles for the purpose of DWI / DUI traffic stops. The devices are used to test a suspect's blood alcohol level. Each machine requires maintenance and regular calibration. These machines, however, do not produce accurate results and, therefore, can only be used as probable cause to arrest someone but are not admissible in court as evidence of driving while intoxicated.

Breath Test

In Texas, the breathalyzer used to test your breath alcohol content (BrAC) is the Intoxilyzer 9000. These machines are permanent as opposed to the portable breathalyzers kept in an officer's vehicle. The Intoxilyzer is kept at the police station and is used to formally test the presence and amount of alcohol in a person's breath sample. The results from this machine are admissible in court. Required by Texas Penal Code § 49.01(1)(a), the Intoxilyzer 9000 analyzes alcohol in grams per 210 liters of breath. 

How Accurate & Reliable are Breath Test Results?

The Intoxylizer 9000 is more reliable than the PBT, but it has inherent problems. On top of that, problems occur with how the breath sample is handled, how the test is administered, and what condition the suspect is in when taking the test, among other things. Below are common reasons for how breath test results are rendered inadmissible, inaccurate, and unreliable.

Poor Maintenance & Calibration of the Breath Machine

Breath machines like the Intoxilyzer 9000 must be regularly calibrated and maintained. There are specific protocols that must be followed. The breath test will not render accurate results unless the machines are well-maintained. The problem is: officers get tired and lazy or third parties hired to do it don't do it. Carl Ceder will request calibration records and notes on the machine used in your specific case, and based on the investigation, he may move to suppress the test results.

Improper or Untimely Administration of the Breath Test

Officers must be trained on the proper use and administration of the breath machine. Even when trained, however, police officers may not remember if they don't perform the test regularly. Also, the prosecutor must prove that you were intoxicated while driving, not intoxicated 45 minutes after your arrest. By the time you make it to the police station, the alcohol in your system has had time to metabolize, and that means there could be more alcohol present in your breath sample than when you were actually pulled over. Improper or untimely administration of the Intoxilyzer 9000 can render results unreliable.

Suspect's Food Consumption

What you eat can affect the breath sample, which in turn can affect the results in a negative way. Many foods have alcohol, like fermented foods. If you just ate one of these food items, then trace amounts of alcohol can still be on your breath. Examples of food and other items that could trigger a false positive include:

  • yeast bread
  • protein bars
  • honey buns
  • hot sauce
  • kombucha
  • vinegar
  • pickles
  • very ripe fruit
  • energy drinks
  • lip balm
  • sugar-free gum
  • mouth wash
  • cold and allergy medicine.

A PBT can be tricked by these types of foods more so than the Intoxilyzer 9000. That said, the problem again is the waiting period between the arrest and the breath test with the Intoxilyzer.

Suspect's Breath Sample

Your breathing can also cause an inaccurate breath test result. The best results are rendered with the breath sample is representative of deep lung air. Many people have shallow breathing, however, and so the breath sample may not be drawn from deep within the lungs. When the sample is from deep within the lungs, then the breath test is more unlikely to be tricked by fermented foods and other things. Remember: any trace amount of alcohol can alter the accuracy of the breath test.

Suspect's Health Condition

The suspect's health condition can also pose problems. Diabetes, asthma, and acid reflex are well-known health conditions that can trigger false positives. Persons with diabetes produce acetone, and the Intoxilyzer can mistake acetone for alcohol. For people with asthma, if you just used an inhaler before getting in the vehicle, it can skew the breath test results. Acid reflux is another problem where sufferers often experience contents from the stomach returning to the throat and mouth, and this can bring with it trace amounts of alcohol. 

Smart, Aggressive DWI Defense Attorney in Dallas-Fort Worth TX

If you are arrested for a DWI in the Dallas and Fort Worth area and took a breath test, Contact Carl Ceder to talk about your options. Breath tests can be used as evidence if not the result of PBT, but they are pieces of evidence that can be successfully challenged. Call today at 469-900-0000 to get started on your DWI defense.