There are a number of factors that lead to blood-alcohol testing that can read incorrectly. It is assumed that the machines are in standard calibration and that test administration was flawless. It is actually rare that the machine is in perfect working condition, yet the experts still maintain that the margin of error for breath test machines is plus or minus .02%. Unfortunately, .02% can be the difference between getting charged with a Minnesota DWI and not getting charged. Blood tests have a margin of error of plus or minus .005%. These facts are why blood alcohol testing can be challenged in court.
It is amazing what can result in a falsely high reading. Heartburn, for instance, can result in a falsely high reading because the alcohol in the stomach can move from the stomach to the throat and into the mouth. If you blow into a breath test machine while you have heartburn, the mouth alcohol level can be higher than the lung alcohol level, which is the level that counts.
It is possible to test falsely by a factor of 4 if you have heartburn, which means a .04 BAC could read as .16. This is double the legal limit. If you have eaten spicy food that has lead to heartburn and you had alcohol with that meal, you could blow a false reading. Even the smallest amount of regurgitation that may not irritate you could cause a high reading.
Substances Resulting In High Readings
If you have decaying food particles in your mouth, it is also possible for the formation of alcohol to occur in the mouth. Taking cold medicine or cough syrup, mouthwash, or homeopathic preparations could result in mouth alcohol.
People who work around certain chemicals may also blow higher results. The reason is because they may absorb some of the compounds and that will cause it to show up in their lung tissue. Such chemicals include nitrous oxide, ethylene, acetronitrile, isopropanol, and tolune. If found in the DWI suspect’s lung tissue, a falsely high reading is going to be blown. Even paint, gasoline, and lacquer fumes can cause a higher result.
Your Diet And High Readings
If you are eating a low carbohydrate, low protein diet, then the ketones that the body produces during metabolism can result in a higher reading. The reason is because drinking alcohol produces the same ketones in the blood and this can form isopropyl alcohol. Most breath test machines are not able to distinguish between the two different types of alcohol. Impairment is only caused by ethanol.
BAC Was Still Rising
When you drank may result in a worse result than how much you drank. The reason is because alcohol can take up to 3 hours to be absorbed into the bloodstream. Your peak BAC may occur at the police station while being given the breath test, making it much higher than it was when you were stopped. When you were stopped, your BAC may have been .06. At the station, your BAC may have elevated to .12.
There are other causes for falsely high results, such as the breathing technique that is used and body temperature. The results can even be contaminated. Your attorney will be able to challenge these results.