7.5 The Intox Ec/ir II 55

• Library: Defense of Serious Traffic Cases in Virginia (Virginia CLE) (2020 Ed.)

7.5 THE INTOX EC/IR II ⁵⁵

7.501 Statutory Regulation of the Breath Test. The Virginia statute directs police to use a breath test unless it is "unavailable" (a term of art) and to use a blood test only in that instance. A blood test is also required

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if the accused is suspected of using other drugs besides alcohol or in addition to alcohol or if the accused is physically unable to submit to a breath test. ⁵⁶ However, in Birchfield v. North Dakota, ⁵⁷ the United States Supreme Court held the government generally must obtain a warrant before administering a blood test absent an exception to the Fourth Amendment's warrant requirement. ⁵⁸

All Virginia jurisdictions use the Intox EC/IR II for breath testing, but not all Intox EC/IRs are the same. Virginia approved the Intox EC/IR II "with the Virginia test protocol," so this model was designed specifically for use in Virginia. ⁵⁹ It is important for counsel to know how this machine works and its proper operating procedures in order to spot test irregularities, inaccuracies, and flaws.

Statutory requirements for obtaining a breath test result that can be used as evidence are contained in the Virginia Code. They include the requirement that the breath test operator be trained and licensed by the Department, ⁶⁰ that the breath test device be approved by the Department, ⁶¹ and that breath test equipment be tested for accuracy every six months. ⁶² Additional regulations concerning the proper use of the machine, ⁶³ storage and care, ⁶⁴ modifications, ⁶⁵ and device selection ⁶⁶ are found in the Virginia Administrative Code.

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Beginning in 2014, the Virginia Department of Forensic Science began posting online the test information records for state-owned machines. ⁶⁷ The breath alcohol instrument records may include certificates of instrument accuracy, instrument maintenance history, quality assurance worksheets, and associated documentation. The department will continue to add more records as maintenance on individual machines is performed.

7.502 Scientific Principles. Breath testing for alcohol is possible because alcohol is eliminated through the lungs in a small but measurable amount. In the alveolar region of the lungs, blood vessels come in contact with microscopic sacs called alveoli. It is here that carbon dioxide in the blood—and any alcohol present in the blood—will transfer into this deep lung air. ⁶⁸

Henry's Law states that "the weight of any gas that dissolves in a definite volume of liquid is directly proportional to the vapor pressure that the gas exerts above the liquid. This proportion differs at varying temperatures, pressures, and volumes." This means that at certain temperatures, a definite ratio exists between the concentration of alcohol in lung air and in body fluids, such as blood. Scientists believe that the ratio of alcohol in alveolar air to alcohol in the blood is 2100 to 1; deep lung air will contain approximately 1/2100th as much alcohol as the blood. ⁶⁹

The Intox EC/IR II relies on two technologies, electrochemical oxidation (fuel cells) and infrared spectrometry, but only the fuel cell analyzes the breath sample to produce the reading. A breath test machine that calculates results using both fuel cell and infrared technologies does exist (the Draeger Alcotest 7110), but Virginia chose not to buy this model.

Experienced counsel should be familiar with infrared technology—it was the only technology used in the Intoxilyzer 5000, the machine previously used in Virginia. An infrared device passes an infrared light beam through a breath sample and measures the amount of light absorbed by the alcohol. The

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higher the alcohol level in the breath, the more light absorbed, which results in a higher reading by the machine. The Intox EC/IR II uses infrared technology to (i) continuously monitor the breath sample to determine the exact moment to introduce the sample to the fuel cell (which is toward the end of a breath) and (ii) detect residual alcohol from the mouth. Since this machine does not use infrared technology to quantify the amount of alcohol in a sample of breath, a lengthy discussion of the science behind the technology— which was critical to understanding the Intoxilyzer—is not necessary.

Fuel cell technology is different. Remarkably, the technology has been available since the early 1800s, but only recently has it been successfully applied to breath testing.

In its simplest form, the alcohol fuel cell consists of a porous, chemically inert layer coated on both sides with finely divided platinum oxide (called platinum black). The manufacturer impregnates the porous layer with an acidic electrolyte solution, and applies platinum wire electrical connections to the platinum black surfaces. The manufacturer mounts the entire assembly in a case, which also includes a gas inlet that allows a breath sample to be introduced.

The chemical reaction that takes place in an alcohol fuel cell converts alcohol to acetic acid. In the process, this conversion produces a fixed number [of] free electrons per molecule of alcohol. This reaction takes place on the upper surface of the fuel cell. H+ ions are freed in the process, and migrate to the lower surface of the cell, where they combine with atmospheric oxygen to form water, consuming one electron per H+ ion in the process. Thus, the upper surface has an excess of electrons, and the lower surface has a corresponding deficiency of electrons. If you connect the two surfaces electrically, a current flows through this external circuit to neutralize the charge. This current is a direct indication of the amount of alcohol consumed by the fuel cell. By measuring the amount of [the] current, you can determine the amount of alcohol in the sample. ⁷⁰

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In other words, the fuel cell reacts with alcohol from a breath sample in a measurable way. The fuel cell is sensitive to types of alcohol other than ethyl alcohol. ⁷¹

7.503 Operating Procedures. An operator begins a breath test by observing the accused for at least 20 minutes. The operator must ensure that the accused has not belched, burped, regurgitated, or placed anything in his or her mouth during this time. ⁷² The operator then presses the enter key to start the machine, swipes his or her test operator's license, credit card-style, and enters the correct PIN number. The machine will then confirm whether the operator is licensed. The operator next swipes the accused's driver's license to input the accused's name, date of birth, and sex (this can also be entered manually), and then enters the appropriate jurisdiction and court. ⁷³

After this information is received, the machine will conduct a diagnostic test. ⁷⁴ This test is internal and not visible. The Department of Forensic Science's manual does not describe what occurs during the Intox EC/IR II's diagnostic test, but Department reports show that it records barometer readings.

Assuming the diagnostic test shows proper operation, the machine will then "purge" itself. This means that it will open the test chamber to take a sample of air from the room—a "blank check." The operator must remove the mouthpiece while the machine does this. Then the machine will pump in a premeasured gas as a form of simulator. If the machine correctly recognizes the known value of this gas, the machine will do a second purge. This is to ensure that the simulator gas will not contaminate the accused's test. ⁷⁵

Now the machine is ready for the accused to submit a breath sample. The operator opens a new mouthpiece, puts it on the breath tube, and instructs the accused to blow. The machine is looking for alveolar air, and this requires a sample of strong, steady breath. If there is any drop in

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pressure, the machine will do a quick purge/?blank check sequence until it gets the steady breath needed. This can go on for three minutes. ⁷⁶

Once the first sample is accepted by the machine, the operator takes off the mouthpiece and allows the machine to complete another purge. This can take up to two minutes. The operator again ensures that the accused has not burped, vomited, and so forth, again places the mouthpiece on the tube, and instructs the accused to blow a second time. ⁷⁷

If the second sample is accepted, the operator removes the mouthpiece. The machine does a final purge and reports the lowest of the two breath results, truncated to the two digits past the decimal point (neither rounded up nor down). These two test results, filed with the Department and available to counsel, cannot be greater than .02 grams/210 liters apart from one another. If they are, the operator must take a third sample, using the same protocol as before. The lowest truncated result of the three readings will be the final reported test result. ⁷⁸

7.504 Flaws in the Analysis. Like its predecessor the Intoxilyzer, the Intox EC/IR II is not a perfect device. For example, it assumes that human breath is 34°C (93.2°F) when leaving the mouth. At this temperature, the ratio between the concentration of alcohol in the blood and in the lungs at equilibrium is 2,100 to 1. But if an individual's temperature were higher than this assumption, the ratio would be different and the corresponding breath test result would show the accused's BAC to be higher than it actually was. For example, if the subject has a fever, the Intox EC/IR II result will be unnaturally high. This problem could be corrected for if the police were to take the subject's temperature before giving the test. A competing breath test device, manufactured by Draeger, does test and correct for breath temperature. Virginia chose not to pay for this technology.

The test also assumes that one does not have a measurable amount of endogenous alcohol—alcohol that develops naturally in the body. ⁷⁹ Moreover, the machine's ratios are set for a hypothetical subject of an average weight, and individual weights vary widely.

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In addition, the device has...