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Are breath test results accurate?

On Behalf of | Oct 5, 2021 | Criminal Defense

If law enforcement officers pull you over on suspicion of driving while under the influence of alcohol or drugs, they will, in all likelihood, request you to take a breath test. Under Indiana’s implied consent law, you agree to take such a test as one of the conditions of getting your driver’s license. If you refuse to do so when the time comes, you face serious consequences, including the immediate loss of your license.

But how accurate are the results these tests produce? A New York Times article warns that the results produced by many breath testing devices can be upwards of 40% too high. In other words, it is not uncommon for a breath testing device to return a falsely high positive.

Factors affecting BAC results

In Indiana, a BAC of 0.08% is presumptive evidence that you are legally drunk. If you are a commercial driver with a CDL, the legally drunk BAC level is only 0.04%.

Unfortunately, many factors, including the following, can contribute to a breath test device returning an inaccurately high result when you take the test:

  • An internal body temperature higher than the norm of 98.6 degrees Fahrenheit
  • Acid reflux
  • A high-stress level
  • Diabetes
  • Medications
  • Improper calibration of the device
  • Inadequate training of the officer using the device

Challenging the evidence

Given the notorious unreliability of breath test devices and the results they produce, if you “fail” one, your wisest course of action is to immediately contact an experienced DUI attorney. He or she may well wish to challenge the damaging evidence in court.