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How Do I Blow Into a Breathalyzer?

The way you blow into a breathalyzer can change the results

The manner in which you deliver your breath sample may affect the results of your DUI breath test results. First, if you attempted to comply with the breath test, but there was a problem with the plastic mouthpiece, this might cause your machine to malfunction. The same can be true of the machine not working if you “over blow” (blow too hard or with too much air being rapidly forced through the breath collection tube). A malfunction in the pressure switch may cause a false reading. If the officer does not realize what is causing the problem, he or she might jump to the conclusion that you refused the test by intentional non-compliance.

Next, you can hyperventilate by crying or by having a “panic attack.” As the air is circulating into and out of your lungs too quickly, the results of the amount of alcohol it reads in your breath does not accurately reflect what amount of alcohol is in your blood stream. Likewise, hypoventilation (holding your breath) can cause a false, elevated test result.

If your body is overheated for any reason such as after exercise or from being in a steam room, this can elevate a breath test reading. Women typically have greater fluctuations in their body temperature due to their menstrual cycle. Also, a simple fever that elevates your body temperature a few degrees can cause a higher breath test alcohol reading that is higher than the real “number.” During menopause, middle-aged women experience wide swings in body temperature in a matter of minutes.

Last, if you took the test while seated and leaning forward, this position may have caused a reflux (movement of stomach contents up your esophagus) of some of your stomach contents, including any alcohol in your stomach gases or free in your stomach. Because the machine automatically considers a ratio of alcohol in your breath as compared to your blood alcohol level, liquid alcohol or alcohol in this stomach gas can markedly increase the reported breath test results.

Air bag residue may cause elevated breathalyzer readings

In some DUI-DWI cases, there is an automobile accident involved. Most automobiles on the road today have air bags. Most air bags are packed either in baking soda or talc, or both. Some newer vehicles have air bags that are packed in a two-stage baffle system. These powdery substances prevent “sticking” of the bag when it deploys. This fine powder inhaled as a result of an air bag crash can create the “Tyndall” effect, which may cause a false reading on any infrared breath testing machine if this powder is exhaled by you into the infrared breath machine, causing erroneously high readings by your breath testing device.

Depending on the recency of inhalation and the quantity of powder emitted, all infrared breathalyzers used in America are susceptible to this same “contamination” of the breath sample chamber issue, if baking soda or talc were part of the airbag system’s packing materials.

The propellants used to launch the air bags are gasses that may also affect the readings of infrared breath analysis devices, depending on which propellant was used in your car. To discover which propellant was used in your air bag, your attorney may have to contact the manufacturer of your car.

The important thing about all of this is to remember if your air bag deployed during any accident, and you submitted to a breath test, you should report this to your DUI-DWI attorney. Other details such as how much time between the accident and any breath test, or the make and model of your car may also be important.

DUI breathalyzer error readings and the importance of the follow-up by the testing officer

If, during your testing, the breath machine came up with an “error” reading on the monitor or the print-out, and you were subsequently considered to have refused to provide a sample, there are several possible reasons. First, you may not have been delivering the breath sample correctly, either because the instructions were not given correctly, they were given correctly but you did not understand them, or they were given correctly and you chose not to perform. If the problem was with either of the first two possibilities, you may have a possible defense to the claim that you refused the test.

Second, if it was not one of these problems that caused an error reading to register on the machine, was there a problem with the machine itself? Did the officer just stop trying to obtain an adequate sample after the first attempt, or did the officer try to reset the machine and start over? Details you remember about these few minutes may lead to the assertion of a defense that you tried to perform, but that the reported result was the fault of the machine.

Last, if the machine came up with an error reading, or several error readings, but the officer and you were still able to finally come up with a sample or samples that the machine found acceptable, these added steps may place enough reasonable doubt in the mind of a judge or a jury to win your case. A victory likely depends on what the officer had to do to get an adequate sample, or what you said or attempted to do that will make the difference in your defense.

In some states, when two or more “error” readings have caused the device to not capture a valid test, the breath testing officer may be authorized to request an alternative type of test, such as a blood test. Also, some error readings may indicate an “interfering substance” has been detected, indicating a possible medical emergency.

Further Reading

If you’d like to learn more about DUI breath tests and DUI breath test machines, take a look at some of our other in-depth articles on the subject below: