Your BAC may not be enough to convict you

On Behalf of | May 8, 2018 | Impaired Driving Charges - Alcohol And Drugs |

When you were in science classes, you may remember thinking that you would never use the information your teacher thought was so important. Little did you know that some of that science would come in handy at the most surprising moment: during an impaired driving arrest.

If Alberta police recently detained you under suspicion of driving while impaired, you may have submitted to a breath test, which provided police with enough reason to place you under arrest. You may feel that the results of the test are enough to convict you of the offence, but there could be some very strong reasons to fight the charges.

Breath tests are not always reliable

Of course, the best way to avoid the serious and potentially life-changing consequences of an impaired driving conviction is by not driving after you have been drinking. However, even if you were certain you were not impaired when you got behind the wheel, a breath test may say your blood alcohol content was .08 or higher. It is not unusual for Breathalyzers to give false positive readings because of the science that makes them work.

For example, alcohol contains ethanol, so a Breathalyzer analyses the amount of ethanol in your system. However, about 80 percent of the compounds on your breath may have a structure similar to ethanol, and the device cannot always tell them apart. Some factors that may give a false BAC reading include the following:

  • You suffer from diabetes.
  • You are observing certain restrictive diets.
  • You have recently consumed certain products containing yeast.
  • You have recently used or been exposed to oil-based paints, contact cement, cleaning fluids or other substances.
  • You have traces of blood, vomit, tobacco or alcohol in your mouth.
  • Police did not adjust the breath machine to your body temperature.
  • Police did not properly calibrate or operate the device.

Studies show that even the electrical interference from a police radio or your cell phone may affect the readings of a breath machine. If you engage in vigorous exercise or hyperventilate, your BAC may even go down. If you are a woman, you may be more likely to garner a higher reading, especially if your lung capacity is small.

The point is that about one quarter of all Breathalyzer results are higher than the actual alcohol content in the person’s blood. If your BAC reading was .08 or greater, you have every right to question the validity of the results.