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How accurate are breath test results?

If you are facing DUI charges in the state of Georgia, you probably understand just how high the stakes are. What you might not understand is how problems with the accuracy of the equipment used to make that determination could determine your future. Having an attorney with experience defending drivers accused of operating vehicles under the influence helps because it not only means you have the aid of someone who understands the law, it also raises the likelihood that you will be hiring an individual who understands just how deep the problems with breath tests run.

Why breath tests are inaccurate

In general and in theory, the use of breath tests should be fairly accurate. They are designed to find ethanol present in the breath, and to measure the amount. The reason this breaks down is because the equipment is not always sensitive enough to sort ethanol from other methyl group compounds in many cases. Different brands of breath testers and different models have widely ranging inaccuracies, but what they all have in common is a tendency to read all of the molecules that are chemically similar enough to be in that group as a positive. This is a problem because:

  • There are hundreds of methyl group compounds.
  • Of the 100 or so compounds regularly found in human breath, upwards of 70 are usually methyl group compounds.
  • Compounds like paint thinner and nail polish remover that contain compounds that can also alter readings, particularly if you have been exposed over a long period of time.
  • Some medical conditions like diabetes increase the amount of compounds like acetone on your breath-the same compounds that can cause false positives.
  • Breath testers also assume a ratio of 2100 to 1 when calculating the amount of ethanol in the breath versus that in the blood, when it actually varies between 1900 and 2400 to 1.

What to do about it

Since Georgia does have an implied consent law with some strict penalties for refusing a breath test, you do need to go along with one if the police ask. The only guaranteed way to avoid that is to entirely avoid drinking when you will have to drive.

In the event that you are given a breath test that shows results that do not measure up, your next best option is to talk to an attorney. Experienced DUI attorneys know how often the breath testing equipment can be faulty and how it happens, and they are in the best position to be able to help you get justice.