Are Breath Machines Reliable?

While a breath machine may give a correct reading, it doesn't always. The accuracy is not reliable. Furthermore, the relevance is questionable, because the alcohol ratio on your breath does not determine whether you are capable of safely drinking. In fact, it does not always accurately measure the actual blood alcohol content in your blood. It's the alcohol content in your blood that accurately determines your intoxication levels. The machines make a huge assumption that the accurate ratio to use when interpreting and deciphering breath alcohol into blood alcohol is a 2100:1 ratio. This is a huge assumption, because in reality, that ratio changes from person to person. Additionally, there are numerous other factors which can affect the readings. such as temperature. Unfortunately, officers rarely even measure temperature to help get an accurate number.

Because blood-breath ratios vary both between individuals, and at different times in the same individual, a breath test based on a 2100:1 blood-breath ratio may not accurately represent a particular individual's blood alcohol level. This is what the Court said in State v. Brayman, 110 Wash.2d 183, 751 P.2d 294, 297 (1988). In that case, the state chemist agreed that partition ratios can vary from 1600:1 to 3000:1, and further acknowledged that other experts have recognized an even greater variance in a small percentage of the population. The chemist explained that if the actual partition ratio were lower that 2100:1 because of factors such as body temperature or the ratio between red blood cells and blood plasma, a breath test would tend to overestimate blood alcohol; the opposite would be true if the partition ratio were higher than 2100:1. At its extremes, the variance could significantly affect test results.

As a DUI defense lawyer, I just finished a drunk driving trial where we attacked the breath machine's credibility. We retained an expert lung physiologist who strongly disagrees with the reliability of breath machines. If you want an accurate reading, of blood alcohol levels, measure the blood for Pete's sake. It's not hard to take a blood sample. Kansas allows blood samples, but officer rarely utilize this more reliable method. Even worse, when they do the breath tests on the Intoxilyzer 8000 in Kansas, they only take one test. They should at least test the breath twice to ensure accuracy. If you've been charged with drunken driving in Kansas, call our law firm to speak with an experienced criminal defense attorney.