Everything You Need to Know About Breathalyzers

Posted by Lawrence Taylor on May 18th, 2006

All states now have two drunk driving laws: (1) driving under the influence of alcohol (aka “DUI”, with local variations, such as “driving while intoxicated” or “DWI”), and (2) the so-called per se law of driving with .08% or higher blood-alcohol concentration (BAC). Most of those arrested will be charged and prosecuted for both offenses.

The breath machines (commonly — and inaccurately — referred to as “Breathalyzers”) used to obtain the BAC are, obviously, critical to the drunk driving case. As for the per se offense, the only evidence of the crime is the machine: if the thing says .08% or higher and the jury believes it, the defendant is guilty. And even as to the DUI charge, the readings will be considered presumptive: if the BAC is .08% or higher, the jury will be instructed by the judge that the defendant is presumed guilty — and he must be found guilty unless he can prove his innocence (I’ve discussed this in “Whatever Happened to the Presumption of Innocence?”).

These machines are all-important: they determine guilt or innocence. But their manufacturers continue to assure us that they are “state of the art”. So how accurate are they?

Well, as I’ve written in the past, not very:

Breathalyzers — and Why They Don’t Work
Close Enough for Government Work
The Mouth Alcohol Problem
Breathalyzers: Why Aren’t They Warranted to Measure Alcohol?
Driving Under the Influence of….Bread?
Warning: Breathalyzer in Use
Breath Fresheners and Breathalyzers
Diabetes and the Counterfeit DUI
Why Breathalyzers Don’t Measure Alcohol
Can Body Temperature Affect Breathalyzer Results?
The Effect of Anemia of Breath Tests
GERD, Acid Reflux and False Breathalyzer Results
Driving Under the Influence of….Gasoline?
Do Breathalyzers Discriminate Against Women?
Breathalyzer Inaccuracy: Testing During the Absorptive State
Breathalyzer Inaccuracy: Post-Absorptive
Breathalyzer Inaccuracy….It Gets Worse
Warning: Smoking Can be Hazardous to Breathalyzer Results
How to Fool the Breathalyzer
Breathalyzer Manufacturers Won’t Tell How They Work

State of the art? Far from it, yet thousands of American citizens continue to be accused and convicted by these machines…..

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