Posted On: February 10, 2013 by Bruce M. Robinson

Breathalyzer Questions and FAQs

Here are a few of the most common DUI breathalizer questions we get:

What are the DUI Breathalyzer procedures in Maryland?
Can multiple blows effect my breathalyzer result?
Does burping during breathalyzer increase my BAC number?
Can I be arrested for blowing a low number?

Maryland's DUI breathalyzer procedures are documented in Maryland Transportation Article 16-205.1 and in COMAR Together they say quite a bit about the requirements for a proper blow and therefore, if interested, you should consult these sections beginning with COMAR because it's easier to decipher and more to the point. Here are some of the requirements in short:

1. The DR-15 rights must be read to you in their entirety or you must be given the form to read yourself, completely, prior to being asked to blow in their magic happy box. If this does not happen, then your breath results should be excluded both in Court and at the Administrative hearing under 16-205.1

2. You must be watched for 20 minutes by LEO (law enforcement officer). You must be watched by either the arresting LEO, the breath operator or some other cop who has time on his hands (in between doughnuts) to make sure you do not put any foreign objects in your mouth or system. Foreign objects like food, alcohol, water, gum, chewing tobacco, etc can potentially have an impact on your BAC score. This is why many times they will not let you go to the bathroom before you blow; although the nice ones sometimes will.


3. They will then sit you down in front of the machine and basically tell you to take deep breath and blow in the machine until they tell you to stop (the machine will indicate when it has had enough of your breath). TIP: The cops tell you to take a great big breath because the deeper and longer you blow, the higher you go! You see when you breath deeply your getting the deep alivolar breath in your lungs number one, where the alcohol exchange takes place from your blood. Thus the more expelled air you get from there the higher your BAC number will be, versus simply inhaling air in your nose or mouth and quickly exhaling it. TIP 2: The deeper you inhale and hold your breath prior to exhaling, the more time the alcohol has to dissipate into the air that you will exhale. Deputy Dawg knows this and will encourage you to take a deep breath, hold and exhale thus maximizing your BAC score. Conversely, shorter breaths which remain in the mouth, breathing passage or lungs for a short period of time lack the same exchange time and thus result in lower or more fair and reflective BAC number.

4. You will be asked to provide two breath samples to the magic box. If the two breath samples are not within .02 of each other (absolute difference), then you will be asked for a third breath sample. Of the three samples, two must correlate within .02, if they do not, the samples will be rejected completely.

5. Before and after you blow, the machine will do a self test and in the self test, the blank test must report .00 BAC (ie. blank) and then must test itself with a known .08 solution (which the machine has attached to it) and the test must report within 10% of .08, ie. the machines margin for error. TIP: Whoops, bet you didn't now that! The magic breath machine has a 10% margin of error right from the manufacturer's own documentation and also in COMAR. Thus, if you happen to blow, say .08 which is enough to find you guilty of the per se charge, it could actually be a .072, under the per se charge. But, who's counting the details? After all, it's only your job, life and freedom on the line right?

Can multiple blows or burping effect your BAC results? In a word- of course! Burping can have a tremendous effect on your reported BAC score. Why? Take a guess... When you burp/gerd or have gastroreflux issues what you are doing in launching lung air into your mouth where it resides directly prior to a blow in the machine. Then you inhale for the blow and provide the machine with your regular breath sample which is exponentially increased by the lung BAC air from the burp. You see, these magic breath machines are actually quite sensitive to alcohol, thus when you have "mouth alcohol" form a burp or from chewing tobacco or gum trapping alcohol in your mouth or orthodontics for example you are seriously impacting the amount of alcohol in your mouth that the machine will read upon exhalation. This can and will seriously skew your BAC results which will cause you considerable problems in court. That is why they cops are supposed to check your mouth for foreign objects, including tongue rings, prior to a blow.

As for multiple blows in the machine, that can also have an effect on your BAC score because each time you blow in the mouthpiece and down that tube, alcohol from your breath can reside say in the mouthpiece. The mouthpiece should be changed between multiple blows, although that is rarely done, it can have a negative impact on your BAC score.

Finally, can you be arrested for blowing a low score in Maryland?

You bet!! The cops don't give a hoot about your BACnumber; that is just one factor among many. If it helps them, great, if it doesn't, forget it. The Court only gives a partial hoot about your number. If the cop smells alcohol on your breath, your going to be arrested (unless by some miracle you ACE the roadside monkey tests), otherwise you're jail meat for the evening. Even if you blow a low score in the machine, he's charging you and getting the credit for the DUI arrest with the brass. TIP: The arresting cop will be paid, many times overtime to go to court and help prosecute your DUI case, irrespective of the final outcome so, what do you think, will you be arrested for blowing a low score?