If you have ever been asked to take a roadside breath test, you may be surprised to learn that the results of the test may have been inaccurate. Law enforcement officers in Pennsylvania and throughout the United States use breath test devices to determine whether drivers are intoxicated while behind the wheel. In some cases, however, these tests may give inflated results, which could lead to wrongful DUI charges and convictions.

The most accurate way to read a blood alcohol level is to take a blood sample. Since this cannot be done alongside the road on a traffic stop, officers ask drivers to exhale a breath sample into the breath test device. The device then measures the amount of alcohol in the breath sample and converts the number to a BAC level reading. Errors can occur during this conversion process, as there are several factors that can influence the readings.

One factor involves the calibration and use of the breath test device. Hand-held devices must be calibrated properly according to the relative humidity and temperature of the environment that it is being used in. Furthermore, the officer must know how to use the device correctly in order to yield accurate results. Even then, other influences can alter breath test results, including the following:

  •          Food, blood or vomit in the driver’s mouth
  •          Static interference from cellphones or officers’ radios
  •          Dirt, pollution or tobacco smoke
  •          Fumes, such as gas and cleaning fluids

Studies show that physical activity and oxygen levels also play a part in the BAC level readings obtained from a device.

This information is intended to educate and should not be taken as legal advice.