Are Breathalyzer Tests Accurate?

Are Breathalyzer Tests Accurate?

Most people are under the impression that the results of a breathalyzer test are scientifically accurate.  Guess what?  They aren’t.   Many factors can raise or lower the results of a breathalyzer test.   I am going to put together a series of short articles addressing several of the factors that can raise or lower test results. 

Recently, on a television cop show I saw a highway patrol officer yelling at a person arrested for drunk driving that he wasn't taking a deep enough breath and blowing hard enough.  My clients often tell me they have had the same experience.  “Come on, my grandmother can blow harder” appears to be a common admonition.    Why do you think the highway officer wants the drunk driving suspect to take a deep breath, hold it and blow hard?  Shockingly, it is because it produces a higher result. 

Holding your breath before exhaling increases the alcohol concentration in exhaled air by 15% to 16%!   A .10 reading could be a .16%.  Why?  Because your deep lung air is warmer and warmer air holds moisture.  More alcohol is trapped in the warmer moist air causing a higher breathalyzer result.  

What that means is that someone who should pass may blow above the legal limit for driving with ability impaired and an impaired driver may produce a test result of an intoxicated driver.