Beating the Breath Test

Many attorneys will look at the breath test results and simply think or say “well, you’re over the legal limit” and pursue other possible defenses or negotiate the best possible plea to the DUI charge.

Our web page 50 Ways to BEAT a DUI has examples of cases and ways in which a Breath Test can be beaten.   It takes a Qualified DUI Firm to properly challenge Breath Test results and we do it on a regular basis. In fact, we have an attorney that is certified in the operation of the same exact Intoxilyzer 8000 breath testing machine which is in use throughout the State of Florida today.

To beat it you have to understand it!

A Breath Test Is an ESTIMATION and NOT a

Many people think that breathalyzers read your blood alcohol content when, in fact, they actually estimate your BAC levels. A breathalyzer attempts to convert your breath alcohol content to BAC by measuring blood alcohol in your breath from the lungs. While a reading suggests more validity, an estimation is what it really is: an educated guess.

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Breathalyzer Calculations are based on
assumptions about you!

People are shocked to learn that the Breathalyzer, or the Intoxilyzer 8000 that is used in Florida, has nothing to do with blood alcohol levels. The Intoxilyzer only measures breath alcohol levels. In fact, the Intoxilyzer doesn’t even use its findings to make a calculation or true conversion from breath to blood alcohol, it ESTIMATES!

Since the Intoxilyzer estimates BAC, their results may be open to interpretation. Consider how the Intoxilyzer does “convert” breath alcohol content to blood alcohol content. In order to make this “conversion,” the Intoxilyzer assumes a standard ratio of 2100:1 between BAC and breath alcohol content. This ratio assumes that the man or woman being tested is an "average person" in terms of weight, health and other factors relating to his or her age group.

It has been shown that this ratio can vary anywhere from 1400:1 to 2800:1 within individuals. In other words, a breath test result of 0.08% may actually vary from 0.5% (under the legal limit) to 0.11% (above the legal limit)!

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Want more on how the Breath Test
calculates your BAC?

To believe that the Intoxilyzer is a valid method of determining your BAC, or Blood Alcohol Content, you must first accept the notion that there is a direct relationship between the amount of alcohol in a person’s breath and the amount of alcohol in their blood. The Intoxilyzer 8000 is calibrated to assume this ratio is 2100 to 1 for everyone being tested. The manufacturer of the machine assumes that:

  • If you took 2100 cubic centimeters of breath and tested the amount of alcohol therein, the amount of alcohol in that sample would be equal to the amount of alcohol in one milliliter of the same person’s blood.

The problem with this method of calibrating the Intoxilyzer 8000 in this manner is that experts all agree that the 2100 to 1 breath to blood ratio is only an average. Bottom line, not everyone has this magical 2100 to 1 ratio. For example, if a person has a ratio lower than 2100 to 1, they will produce an Intoxilyzer result that will be artificially high. If a person has a breath to blood ratio higher than 2100 to 1, they will produce an Intoxilyzer result that will be artificially lower. To date, the company that manufactures the Intoxilyzer, (CMI Corp.,) has yet to invent a method that would calculate the driver’s true ratio and then make the appropriate correction for a more accurate breath test result.

Consider the following excerpt from just one study a well known Psychiatric publishing, “In the United States breath alcohol tests are calibrated with the amount of alcohol (in grams) in 210 liters in breath, presumed to be equal to the amount of alcohol in 100 milliliters of blood—a blood-breath (to alcohol) ratio of 2,100:1. In practice, the blood-breath ratio is highly variable, with reported values ranging from 1,981:1 to 2,833:1.” Psychiatric Serv 57:34-36, January 2006, Glenn W. Currier, M.D., M.P.H., Adam J. Trenton, B.A. and Patrick G. Walsh, B.S.


This study found the blood-breath ratio to be highly variable! Scientific studies and evidence such as this can help demonstrate the possible inaccuracy in your breath sample, but also consider how inherent error , acceptable range , and the calibration range can also bring doubt upon your results!

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What does Florida Law require for
breath samples to determine BAC?

Florida Statutes, Section 316.193 provides that a violation of the law has occurred if:

  • The driver had a blood alcohol level of .08 or more grams of alcohol per 100 milliliters of blood; or
  • The driver had a breathalcohol level of .08 or more grams of alcohol per 210 liters of breath.

As you can see, there is a very different standard of alcohol concentration in the measurement of breath versus blood. Does that mean the Intoxilyzer machine requires you to produce a breath sample sufficient to fill 210 liters? No, to the contrary you only have to fill a sample chamber big enough to hold 80 milliliters of air. But what it does mean, is that because of your inability to produce a sample 210 liters in size, the machine has a huge task to perform. For instance, in order to produce a .08 reading on the Intoxilyzer, the machine is forced to detect less than one millionth of one fluid ounce of alcohol in your breath sample! That amount is smaller than what would fit on the head of a pin. Given this minute size, wouldn’t you think that checking the machine’s obvious critical calibration criteria before having a driver submit to the test would be imperative to verifying the accuracy of the results?

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Just ONE or TWO drinks could result in
an Illegal BAC!

Many people may think that they can have a few drinks and still be able to legally drive. This notion is not always true as BAC can vary within people based on many factors. For example, if you are below the average weight of your age group and haven't eaten all day, a couple of drinks may be enough to push you to 0.08%.

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Is there an INHERENT ERROR in
the breath test machine?

Well, scientists seem to think so! Scientists universally recognize an inherent error in breath analysis, generally of plus or minus .01% in the reading. That means that if everything is working perfectly, which is unlikely, a .10% breathalyzer test result can be anywhere from .09% to .11%. This has been acknowledged by courts across the country (see, for example, People v. Campos, 138 Cal.Rptr. 366 ( California) and Haynes v. Department of Public Safety, 865 P.2d 753 ( Alaska);  in State v. Boehmer, 613 P.2d 916 ( Hawaii), the courts have recognized an even larger .0165% inherent error).

Taking the .01% variance in the reading, what do we have? Well, with a .08 reading it would be an astonishing +/- 12.5% either direction! Or, put another way, anywhere within a 25% margin of error. So, will a jury be convinced if you have a breath test result of .09, that it is accurate? Does that sound like guilt proven beyond a reasonable doubt? Keep reading, there’s more!

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What about the “ACCEPTABLE RANGE”
of breath test results?

Florida Law requires that the Breath test Operator must take two sample of your breath for the test to be valid and the law further requires that the two tests must be within a specific amount of one another. That amount is referred to as an “acceptable range.” In Florida the acceptable range is .02! That’s right, .02, or within 25% of the required total (.08) to be found to be driving over the legal limit! Thus, if you have a .082 and a .102, then that is sufficient to satisfy Florida Statutes for DUI, even in the example above where the person’s breath sample readings were approximately 20% apart. To put it another way, if you blew a .10 your first time, then your second blow can be anywhere from .08 to .12 and be valid and supposedly accurate? That’s a 40% range of accuracy! You may wonder, if the machine is so accurate, why is such a variance in the breath sample permitted? Keep wondering!

Most states have standards for breath testing. Although some states only provide for a single breath test, most require that two breath tests be given — like Florida. But what if the two tests are outside of the acceptable range? Well, the officer simply keeps testing! That’s right! If the tests fall outside of the given range (+/- .02 reading), there must be a third test. If the tests results are .15, .10 and .12, for example, the test would be a valid. That’s as much as a 50% accuracy range!

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Put it all together and what do you have?

An “ inherent error” of +/- .01% in the BAC reading, which could reasonably amount to a 25% range of accuracy in a .08 case;

An “ acceptable range” of +/- .02 in the BAC reading, which could reasonably amount to a 40% range of accuracy in a .08 case;

And yes, there’s even MORE!

The calibration tests performed by the breath test maintenance operator at the agency also has an acceptable “calibration range” of .005% (on a .08 test which must be between .075 and .085), which could reasonably amount to a 12.5% range (.005/.08 X2) of accuracy in a .08 case!

Now, taking all this into consideration, does that sound like guilt proven beyond a reasonable doubt? Arguments like these alone can bring significant doubt as to whether or not a breath test is accurate, especially on a reading of .12 or below! But, even if the reading is higher, this argument coupled with others can bring doubt to a juror’s mind as to the reliability and accuracy of the testing procedures and the machine itself!

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Examples of ways to suppress
Breath Test Evidence

There are numerous ways in which a Qualified DUI Firm may be able to get your Breath Test suppressed from evidence. You can refer to our Recent Court Victories or 50 Ways to BEAT a DUI to see that just because you have a reading over the legal limit does not necessarily mean that you will be convicted of DUI. For example, if the initial stop of your vehicle was unlawful or your arrest was unlawful, then the breath test would be suppressed. However, even if your stop and arrest were valid, you can still challenge the breath test results in many ways! Some common things to look at include the following:  

  • Did the officer observe you for the required 20 minutes immediately prior to you taking the breath test?
  • Did you have Mouth alcohol contamination?
  • Was the Breath test administered to you by an unlicensed person?
  • Was the Breath test administered to you by an unqualified person?
  • Were you instructed to “keep blowing” during the breath test?
  • Was the breath test machine properly maintained by the agency and the FDLE pursuant to Florida Law??
  • Did unauthorized individuals have access to the breath test room or the chemicals used for maintenance?
  • Was there any RF interference with your breath test due to the officer having his/her radio on during the breath testing procedure?
  • Was the breath testing machine properly calibrated?
  • Is your body’s partition ratio above or below the 2100:1 ratio the breath test is based upon?

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Other issues that can affect the
accuracy of a breath these are:

Other issues that can affect the accuracy of a breath these are:

  • power surges,
  • mouth contaminates (smokeless tobacco, dentures, denture adhesives, mints, lip balm etc),
  • physical problems,
  • breath temperature,
  • exposure to certain chemicals,
  • certain medications,
  • diabetes,
  • certain diets,
  • esophageal hernia,
  • heartburn,
  • liver disease,
  • machine malfunctions,
  • improper maintenance,
  • radio frequencies, and
  • improper training.

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More factors that could contribute to an
inaccurate Breath Test!
  • Belching or burping: In order for the Intoxilyzer to operate properly, it utilizes a deep lung or "alveolar" air sample. However, regurgitation or refluxing from the stomach can introduce pure alcohol into the sample chamber, which would almost certainly result in an inflated reading.
  • A fever: The Intoxilyzer machine is also calibrated to assume that your breath temperature is normal (34 degrees centigrade). Well, as your body temperature rises, the blood to breath ratio decreases. Therefore, a breath sample temperature higher than normal will result in an inflated reading of approximately 6 to 7% for every degree above 34 degrees centigrade. There is a new machine produced by the Draeger Corporation which has corrected this problem as it measures the breath temperature of the subject and then makes the appropriate adjustment before calculating the results. Unfortunately, this is not the machine in use in Florida.
  • The presence of acetone in your breath: The Intoxilyzer is subject to misreading acetone as ethyl alcohol. Acetone can be caused by diabetes or from fasting. Although the machine attempts to detect this substance and warn the operator, but does it all the time, and does the State or its Breath Test Operator know this?
  • Mouth alcohol: The presence of residual alcohol in the mouth can produce inflated artificial Intoxilyzer readings. Dentures and partial plates have also been known to trap alcohol and to restrict the body’s natural ability to self-cleanse the mouth within a 15 to 20 minute time period. Breath sprays, mouth washes, and other over the counter inhalers often contain ethyl alcohol. The Intoxilyzer uses a "slope detector" to help determine the presence of mouth alcohol. However, the machine is less than perfect. Even if there is a 20 minute observation period, does the police officer know if you regurgitated or belched? So, even if the officer says he did the 20 minute observation he may not know whether you belched or had mouth alcohol.
  • Inhalation of air bag talc: Air bag deployment causes the release of thousands of small particles of talc into the vehicle’s passenger compartment and the driver’s inhalation of this material may cause inaccurate readings upon later exhalation into the Intoxilyzer. It is suspected that the particles of talc floating in the sample chamber absorb or displace light energy during the infrared spectroscopy and inadvertently produce an artificially inflated result.

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You May STILL BE CONVICTED of DUI despite a
Legal BAC Test Result!

Assuming that the breathalyzer made an accurate estimation of BAC, some people may be of the opinion that they can not be convicted of DUI if the breath test result is below 0.08%. This is not always true. You may still be charged and later convicted of DUI if you fail field sobriety tests in spite of your breath test result.

And if you're under the age of 21, merely having any alcohol on your breath may be enough for a DUI charge and conviction. All 50 states have strict zero tolerance policies which make it illegal for underage drinkers to operate a motor vehicle with a BAC at 0.02 or even lower.

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What are FDLE (Florida Department of Law Enforcement) Requirements for the machine
you were tested on?

Was the Intoxilyzer machine used in your case properly registered and approved for use by FDLE? Florida Administrative Code 11D-8.003(2) requires that every Intoxilyzer machine used for law enforcement evidentiary purposes in the State of Florida be registered and approved by FDLE.  In order to demonstrate compliance with this provision, the Prosecutor must produce a valid FDLE Registration Certificate corresponding to the specific machine used in your case.

Can the State produce proper documentation to show that an annual calibration check was performed on the Intoxilyzer machine used in your case?   Florida Administrative Code 11D-8.004(3) requires that all evidential breath testing machines be inspected by a Regional Alcohol Breath testing Inspector employed by the Florida Department of Law Enforcement once each calendar year.

During FDLE’s annual calibration check, did the Department Inspector properly test the range of the Intoxilyzer’s accuracy? Florida Administrative Code 11D-8.004(2) requires a minimum calibration testing by FDLE of ten tests, at each of three known alcohol concentration levels. 

Did the calibration checks performed by both the Agency Inspector and the FDLE Department Inspector reveal test results that fell outside of permitted deviation ranges? Florida Administrative Code 11D-8.002(1) requires that the calibration checks result in a machine falling within the following acceptable ranges:

For a known .05 alcohol concentration the range is .045 - .055

For a known .08 alcohol concentration the range is .075 - .085

For a known .20 alcohol concentration the range is .190 - .210

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What are Local Law Enforcement Agencies (Florida Department of Law Enforcement) Requirements for the machine you were tested on?

Can the State produce proper documentation to show that a calibration check was performed in the month in which your test was administered? Florida Administrative Code 11D-8.006(1) requires that a police agency’s inspector must perform specific regulatory inspections on all evidential breath testing machines at least once every calendar month. 

Was the Agency Inspector properly licensed in compliance with Florida Administrative Code 11D-8.002(5) and 11D-8.008(2) to perform calibration checks as evidenced by their FDLE Permitting Certificate?   If the Agency Inspector was properly licensed, had their permit lapsed beyond the four-year period specified by Florida Administrative Code 11D-8.008(3)?

During law enforcement’s calibration checks, did the Agency Inspector properly test the range of the Intoxilyzer’s accuracy? Florida Administrative Code 11D-8.002(1) requires minimum calibration testing by law enforcement of multiple tests, at three known alcohol concentration levels.

Was the Intoxilyzer Operator in your case properly licensed in compliance with Florida Statutes Chapters 316, 322, 327 and Florida Administrative Code 11D-8.002(17) to lawfully conduct breath testing? If the Intoxilyzer Operator was properly licensed, had their permit lapsed beyond the four-year period specified by Florida Administrative Code 11D-8.008(3)?

If you provided a breath sample at a DUI Checkpoint or Roadblock, was the Intoxilyzer used relocated from a former stationary facility? Florida Administrative Code Section 11D-8.006(2) provides for additional calibration checks when a breath testing instrument is used in a mobile breath testing vehicle. This rule mandates that further agency inspection shall be conducted Prior to the instrument’s removal from the police department; Again, upon the relocation of the instrument into the mobile breath testing vehicle, and prior to it being used for mobile evidentiary breath testing purposes.

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What Does Florida Law require
of the State Attorney?

Florida Statutes (Section 316.194(3)) provides that the State Attorney may introduce breath test results only upon a showing of “substantial compliance” with the administrative rules.  If you can demonstrate a failure to comply with the administrative rules or statutes pertaining to breath testing procedures or maintenance, then you may be able to suppress the breath test results in your case, which may lead to a dismissal of your DUI charge; or if there is grounds for the filing of a motion, at least put yourself in a much better bargaining position (if the State realizes that the test results may be suppressed).

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Effects of Alcohol at Specific BAC Levels

Effects of alcohol intoxication are greatly influenced by individual variations. Some people may become intoxicated at a much lower BAC level than indicated below. Oftentimes we can use these examples to demonstrate that the Breath Test results must be invalid and high because our clients did not appear consistent with these standards.

0.02 — 0.03 BAC:    No loss of coordination, slight euphoria and loss of shyness. Depressant effects are not apparent. Mildly relaxed and maybe a little lightheaded.

0.04 — 0.06 BAC:   Feeling of well-being, relaxation, lower inhibitions, sensation of warmth. Euphoria. Some minor impairment of reasoning and memory, lowering of caution. Your behavior may become exaggerated and emotions intensified (Good emotions are better, bad emotions are worse)

0.07 — 0.09 BAC:   Slight impairment of balance, speech, vision, reaction time, and hearing. Euphoria. Judgment and self-control are reduced, and caution, reason and memory are impaired (in some* states .08 is legally impaired and it is illegal to drive at this level). You will probably believe that you are functioning better than you really are. ( * —As of July, 2004 ALL states had passed .08 BAC Per Se Laws. The final one takes effect in August of 2005.)

0.10 — 0.125 BAC:   impairment of motor coordination and loss of good judgment. Speech may be slurred; balance, vision, reaction time and hearing will be impaired. Euphoria. It is illegal to operate a motor vehicle at this level of intoxication in all states.

0.13 — 0.15 BAC:   Gross motor impairment and lack of physical control. Blurred vision and major loss of balance. Euphoria is reduced and dysphoria* is beginning to appear. Judgment and perception are severely impaired.
( * —Dysphoria: An emotional state of anxiety, depression, or unease.)

0.16 — 0.19 BAC:   Dysphoria predominates, nausea may appear. The drinker has the appearance of a "sloppy drunk."

0.20 BAC:   Feeling dazed/confused or otherwise disoriented. May need help to stand/walk. If you injure yourself you may not feel the pain. Some people have nausea and vomiting at this level. The gag reflex is impaired and you can choke if you do vomit. Blackouts are likely at this level so you may not remember what has happened.

0.25 BAC:   All mental, physical and sensory functions are severely impaired. Increased risk of asphyxiation from choking on vomit and of seriously injuring yourself by falls or other accidents.

0.30 BAC:  STUPOR. You have little comprehension of where you are. You may pass out suddenly and be difficult to awaken.

0.35 BAC:  Coma is possible. This is the level of surgical anesthesia.

0.40 BAC and up: Onset of coma, and possible death due to respiratory arrest.

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New Florida Law Regarding DUI and Auto Insurance

Council Substitute for House Bill No. 359 (Insurance Coverage for Persons Convicted of DUI) - Effective June 15, 2007

As of October 1, 2007, any person convicted of DUI after that date will be required to carry insurance of $100,000/$300,000 bodily injury/death policy limit and a $50,000 property damage policy limit at a minimum.  The driver will be subject to the requirement for a period of at least 3 years.

This provision will apparently be enforced by requiring proof of such insurance coverage at the time of applying for motor vehicle registration.  In the event proof of such insurance coverage cannot be shown, the registration will not be issued.

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