Most of us are at least somewhat familiar with the technique known as a breathalyzer test used by law enforcement during a DUI stop to establish whether or not the suspect was driving with more than the legal limit of alcohol in their system.  The question is, just how reliable are those tests, and can submitting to one make your case more difficult than if you had refused?

Can I be Forced to Take a Breathalyzer Test?

While you cannot be forced to take a breathalyzer test after being stopped for suspicion of DUI, most police officers present it as mandatory. In truth it’s difficult to assess whether you should refuse the test or not, as there are many factors involved. The bottom line answer probably depends on just how intoxicated you are coupled with how badly you need to drive. Driving is considered a privilege rather than a right in our country, and as such most all states will immediately yank your license should you refuse to submit to a breathalyzer test.

Now, if you don’t depend on driving to get to work, and could actually do without your license for a while, and if you realize you are fairly intoxicated, then by all means refuse the breathalyzer test as it only gives the state evidence against you. On the other hand if you are fairly certain you are under the .08 legal limit, don’t refuse the test just because you can. You don’t want to have your license taken away just for being stubborn. If you are drunk, yet coherent enough to realize it, you might as well refuse the test because it will only add to your troubles. As you can see, there is no easy answer to this question, and unfortunately most people who have consumed a fair amount of alcohol are in no position to clearly weigh the pros and cons prior to submitting to the test.

Are the Tests Accurate?

A substantial number of scientists and other experts believe that the breathalyzer tests, as administered by law enforcement are fairly inaccurate in their ability to measure total blood alcohol content. When you consume alcohol it appears in your breath as a result of the absorption primarily through the throat and mouth, but also from the intestines and stomach, into the blood. The blood passes across the lungs, and during this process a certain amount of the alcohol moves through the coating of the lung air sacs into the air. Theoretically this means that the concentration of the alcohol in your breath is roughly the same as that in your blood.

How Does the Machine Calculate my BAC?

As you breathe into a tube which leads to a breath sample chamber, the breathalyzer machine captures a sample of your breath, measures the alcohol content and uses the 2100:1 formula (2100 parts of your air equals one part blood) to calculate your BAC. More than one court has reversed a DUI conviction on the basis that tests such as these are inherently unreliable.  Even though in theory the breathalyzer tests on a 2100:1 blood-breath ratio, in reality those ratios have been shown to vary from 1100:1 to 3200:1, producing errors in the final test results.

The Margin of Error

Studies have shown that high readings are taken in as many as 14% of the (totally sober) population, meaning the reliability of the testing method is significantly compromised. Additionally, the temperature of the machine itself varies considerably which in turn affects the final test results, and because body temperature—which varies between human beings—is also a factor, the test results can be skewed as a result.

Police Error

Finally, the reliability of the breathalyzer test can be significantly altered should the police officer not follow proper procedure. An officer may neglect to properly calibrate the machine, or may not take the time to determine whether or not the subject is affected by the ambient environment.  A skilled Florida DUI attorney will be able to challenge the accuracy of the breath test, so it’s extremely important that you get a lawyer on board as soon as possible following your arrest.

Most people who have never been charged with a DUI in Florida do not understand the relatively high potential for inaccuracy of breath alcohol testing in DUI cases.  Some people arrested for DUI in Florida presume that a breath test device is like a calculator meaning that as long as the data is correctly entered into the electronic device, it will consistently produce the same accurate result.  When using a calculator, users are not troubled by the fact that they cannot see and do not understand what is happening inside the device to convert the input data into the result.  Unfortunately, there are many flaws in this analysis when applied to a breath testing device, which may form the basis for successfully attacking breath alcohol concentration (BAC) testing in Florida DUI cases.

There are two key big picture issues to keep in mind.  The first is that a portable breath test device does not and cannot directly measure the volume of alcohol in your blood.  In fact, the breath test machine does not even directly measure alcohol.  The other key deficiency in breath testing is that it relies on a tiny breath sample that is so minute that it is invisible to the naked eye.  If you held 0.0 percent alcohol in one hand and .16 percent alcohol in the other, you would see nothing in either hand.  This means that the difference between 0.0 percent alcohol and .16 percent, which is double the legal limit for DUI in Florida, is so minute as to be invisible.

This important because when dealing in such small samples even the most minor error can result in enormous errors in BAC test results.  A minor variance in procedures can cause huge variance in BAC results.  These two basic facts often provide Florida DUI lawyer John Musca with a variety of approaches to challenging breath testing results:

Calibration Issues: Our DUI defense firm routinely seeks discovery of the maintenance and calibration records for breath test devices.  Even where the records seem flawless, a Florida DUI attorney may find other issues to raise in your defense related to calibration of the breath test device.  For example, Musca may be able to question when the thermometer in the simulator was most recently checked for accuracy.

Breath Test Operator Issues: We may also attack the credentials, training and procedures employed by the breath test operator.   The operator must wait for a twenty minute observation period to elapse before conducting a breath test.  If the waiting period is not observed, mouth alcohol may be present, which has not been absorbed by the intestines or stomach into the blood in the lungs.  A breath test device uses a ratio that converts the amount of alcohol in lung breath to the amount of alcohol in one’s blood.  This conversion is done using a ratio called the “partition ratio.”  Alcohol in the mouth has not been metabolized by the body so the partition ratio will greatly inflate the results based on the higher volume of alcohol in mouth alcohol.

Absorption Phase: It is important that DUI is not directly based on consuming any particular quantity of alcohol but rather the amount of alcohol in your blood.  If you have consumed your last drink shortly before being pulled over, your BAC may rise between the time you were driving and when the breath test was conducted.  It is your BAC when driving that may be the basis for a Florida DUI conviction, which may differ from you BAC at the time the test is administered.

Other Breath Testing Issues: Depending on the specifics of your Florida DUI case, there are other issues that we may raise which can impact breath test results, such as elevated body temperature due to illness, alcohol trapped in dentures, radio frequency interference with the breath testing device and high hemocrit levels in one’s blood.

The fundamental point is that slight variations in procedures and other factors can substantially impact BAC results obtained from breath alcohol testing.  Our Florida DUI law firm is dedicated to aggressively challenging breath test results when defending our clients from the harsh penalties associated with Florida DUI charges.  We invite you to contact a Florida DUI defense attorney at Musca Law to schedule a free confidential consultation at (800) 687-2252 to see how we can help.

Every person within the world has his or her own individual physiology. This means that there is absolutely no way to measure how people metabolize foreign elements in their blood streams such as: alcohol. Furthermore, there are many other things that affect the break down of alcohol in the human body. One of those elements could be smoking.

Smoking has been shown to hinder the reading of blood alcohol levels (BAC) during a breathalyzer test; smoking has the ability to change a person’s blood alcohol concentration at any given point in time. With that being said, smoking is now becoming more popular after drinking alcohol because if one is pulled over and administered a breathalyzer, the cigarette smoke inhaled into the body changes the BAC and might get someone out of a driving under the influence offense (DUI).

A recent study has shown that cigarette smoke when inhaled into the body absorbs alcohol out of the blood. The study involved taking a group of smokers, and letting them drink alcohol and then smoke. Then the study took the same smokers, and made them be abstain from cigarettes while drinking alcohol. It was shown that the smokers who smoked cigarettes while drinking alcohol had significantly less blood alcohol concentration (BAC) levels than those who abstained from smoking.

However, since breathalyzers are not made for detecting alcohol alone, they can be prone to giving a false reading; especially to smokers. Breathalyzers are specifically made to detect any methyl group in its molecular form-so its not limited to alcohol alone. Therefore, a breathalyzer cannot tell the difference between a compound such as alcohol, and a compound that is acetaldehyde. Acetaldehyde is created and produced in small amounts by the liver, and is also a by-product of alcohol’s metabolism in the blood stream.

However, the fact that smoking reduces the blood alcohol concentration levels in a person’s body is not a reason to think one can drink and drive and get away with it, or that it is okay. The risk of drinking and driving not only produces harm to the driver, but other drivers on the road as well.

It is careless and risky to drive when one has consumed alcohol, and even though it is possible to smoke and reduce one’s BAC, an officer can still cite someone for a DUI offense, because there are other tests besides the breathalyzer. Either way, the smartest and safest thing to do is to drive sober, and abstain from ever getting behind the wheel drunk.