What is the Margin of Error in a Breathalyzer Test?

By Jonathan Blecher on June 14, 2017

To this day, breathalyzer results are often relied upon as strong and conclusive evidence that an individual is guilty of drunk driving. Unfortunately, it has slowly become more apparent that these results don’t hold the irrefutability some have claimed. Researchers, scientists, and attorneys have spent years analyzing breathalyzer machines to arrive at similar conclusions: things are not as they seem.

Why are breathalyzers so faulty?

It is helpful to first understand how a breathalyzer machine operates. The suspect blows air into a device, which is then supposed to calculate the amount of alcohol in their system. However, the calculations are based on mere averages and therefore not unique to each test-taker.

The breathalyzer determines a person’s blood alcohol content (BAC) by multiplying the content of alcohol in the air by 2,100. This number is used because the “average” person typically has 1/12100th the amount of alcohol of an equal gallon of blood when they exhale. Clearly, what is average for one person may be far from correct for another.

Studies have shown that breathalyzer results vary at least 15 percent from the actual BAC. This is a significant deviance that officers fail to take into consideration. Compounding this problem is the fact that at least 23 percent of all tested individuals will get results that are higher than their actual BAC!

There are also numerous factors that can influence a breath test reading,but are often ignored by law enforcement.

Results can be tainted by any of the following:

  • Carbonation
  • Body type
  • Age
  • Fat/muscle content
  • Alcohol intolerance
  • Food consumption

What officers are taking at face value is clearly far from the truth. Many times, tests are administered improperly and the alleged offender suffers as a result. It is imperative that you retain a lawyer who will challenge your breathalyzer results. Simply sitting back and expecting a breath test to work in your favor rarely bodes well for those facing DUI charges.

The sooner you take action, the higher your chances for a favorable outcome.
Schedule your free consultation by calling Miami DUI Attorney Jonathan Blecher today at 305-321-3237.

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