1. G.E.R.D.: Those who suffer from disorders of the digestive tract such as Gastro-Esophageal Reflux Disorder might be at risk for artificially inflated “breath” alcohol readings. This potential inaccuracy stems from the limitations of “breath machines”. When a subject blows into the tube of a breath machine, the computer program installed in the machine assumes that the “breath” it receives is from deep lung exhalation. Unfortunately if such is not the case the result will be skewed.

G.E.R.D. results from a weakened sphincter muscle at the top of the stomach. When this muscle is unable to “pinch” tightly enough, stomach contents re-enter the esophagus and in some instances the mouth of the subject. If those stomach contents contain alcohol, the alcohol vapor from the GI tract can be added to the vapor from the “deep lung” air during the breath test, resulting in an inflated reading. The machine prints a result without determining the actual source of the alcohol vapor.

In the DUI legal environment, the undigested alcohol in one’s stomach has not yet entered the bloodstream and therefore cannot cause or contribute to any perceived impairment. Yet without the proper presentation of this possible explanation to the Jury or Court, an unfair result could occur.

2. Breath Temperature: Breath machines are programmed with a set of assumptions based on average human physiology along with other scientific assumptions from the fields of Chemistry and Physics. The machines assume an average incoming breath temperature. If the person providing the sample has a fever, the breath test result will be inaccurately inflated or overestimated by the machine.

3. Machine Malfunction: Breath machines are essentially a computer attached to several peripheral devices. Each of these devices and the software driving them is subject to the same glitches, malfunctions and useful life expectancy of any other device. A thorough investigation is the only way to uncover records of such malfunctions. The inherent flaws in the theories underlying breath testing must also be exposed in order to fully challenge a breath test DUI charge.

There are a growing number of newly discovered breakdowns on the EC/IR machines used throughout Illinois. Some of these breakdowns have not been properly documented by the Illinois police agencies charged with the obligation to maintain certain records. This can lead to the exclusion of breath tests even in cases where the breakdown occurred on someone other than the Defendant of a particular DUI

4. Extrapolation: Alcohol enters the blood stream through the normal process of digestion. Alcohol that is not yet digested has no effect on a person’s mental or physical capabilities. Many factors affect the rate of absorption of alcohol into the blood stream. Likewise alcohol is metabolized and eliminated through normal bodily processes.

It is possible to estimate a persons B.A.C. (blood alcohol concentration) by analyzing the factors affecting absorption/elimination of alcohol. This technique is called reverse extrapolation. In certain cases, extrapolation can be a very helpful tool to educate a jury. It is most effective in cases involving a B.A.C. that is lower at the time of driving than the B.A.C. at the time of later breath testing.

5. Carry Over: Alcohol molecules have an affinity to water molecules. In layman’s terms water is an alcohol magnet. When a person is required to blow into the same breath machine multiple times the machine’s estimate of B.A.C. may be affected by the carry over effect.

When we exhale, our breath is laden with water molecules. This is easily shown by exhaling onto a glass surface. The internal portions of some breath machines have no way of fully eliminating that moisture from a previous blow into the breath tube. Therefore the alcohol that has attached itself to those water molecules can be added to the reading from a subsequent breath attempt. We see this scenario more and more as aging machines experience solenoid errors, or the subject has asthma or other lung disorders that affect their ability to exhale.