Excerpts from Drunk Driving Defense, 5th Edition By Lawrence Taylor

8.0.2 The Fallacy of the "Average Person"
One of the greatest sources of error in blood-alcohol testing is the consistently recurring fallacy that the individual tested is perfectly average in certain critical physiological traits. Put another way, obtaining an accurate blood-alcohol reading is completely dependent on the validity of a number of scientific assumptions. Unfortunately for the person being tested, these assumptions are usually incorrect: The person tested is rarely "average" in even one of these critical characteristics, let alone in all of them.

Counsel in a DUI case will constantly be confronted by these almost hidden assumptions. And it is very important that these false premises be brought out for the jury—along with the fact that the final readings fall with the presumptions.

Thus, for example, all breath testing devices depend on the assumption that the ratio between alcohol in the exhaled breath and alcohol in the blood is 1 to 2100. In fact, the machine is designed to produce a reading based on that assumption; the accuracy of the reading is directly tied to the accuracy of the presumption. Yet, as will be discussed more fully in 8.1.1 the actual ratio in any given individual can vary from 1:1300 to 1:3000, or even more widely. Thus a person with a true blood-alcohol level of .08 but a breath-to-blood ratio of 1:1700 would have a .10 reading on an "accurate" breath testing instrument.

Put simply, these machines do not test individuals. Rather, they test the average person over and over again, but using the subject's breath.

Yet another example of the assumption of "averageness" can be found in urinalysis. When a subject's urine is analyzed for blood-alcohol, a presumption exists that there are 1.3 parts of alcohol in the bladder's urine for every 1 part of alcohol in the blood. This 1:1.3 ratio is as fallacious as the 1:2100 ratio—that is, it is based entirely on the ratio found in the average person. As is discussed more fully in 8.4.1 however, the actual ratio found in any given individual can vary greatly. And as the ratio is in error, so will be the final blood-alcohol reading.

Another example of this constant reliance on averages shows itself when the prosecutor offers evidence of retrograde extrapolation (see 8.0.6) The blood-alcohol level at the time of testing is not relevant to the charge, of course and so the state will offer evidence to show what the level was when the defendant was driving. This is commonly done by extrapolating backward—that is, computing the earlier blood-alcohol level by estimating how much alcohol had been eliminated or "burned off" in the interim between driving and testing. But this requires two assumptions: The blood-alcohol level was declining and the rate of elimination is known. This second assumption involves the further assumption that the "burn-off" rate was .015 percent per hour. How does the prosecution know that the defendant was eliminating (assuming he was eliminating) at that rate and not at .005 percent or .3 percent! Quite simply, the prosecution does not know: It merely assumes that the defendant eliminates at the average rate. And, of course, error in such an assumption translates into error in the extrapolation.

This ubiquitous "average person" in the DUI arena is not limited to chemical analysis. We even find him with the arresting officer in the field. When the officer administers the increasingly common "horizontal gaze nystagmus'' test as part of the battery of field sobriety tests, he operates on the assumption that the suspect is "Mr. Average." As has been discussed in 7.4, the officer has been trained to "read" at what angle the suspect's eyes begin jerking. A blood-alcohol reading can theoretically be obtained by subtracting the angle from 50; jerking at 35 degrees, for example, would mean the suspect has a blood-alcohol level of .15 percent. Where does the magic figure of 50 come from? The average person.

An alternative method of administering the nystagmus test is to "flunk" the person if jerking begins before 40 or 45 degrees. Why? Again, because the average person would theoretically have .10 or .05 percent alcohol in his blood at this point.

In either test, of course, we do not know what the individual's actual "baseline" is—that is, the angle at which his eyes would begin jerking if he were sober. In both cases, the individual is assumed to be physiologically identical to the theoretical "average" person.

8.1.2 Nonspecific Analysis
One of the major defects in many methods of blood-alcohol analysis is the failure to identify ethanol (also referred to as ethyl alcohol) to the exclusion of all other chemical compounds. To use the terminology of scientists, such methods are not specific for ethanol: They will detect other compounds as well, identifying any of them as "ethanol." Thus a client with other compounds in his blood or breath may have a high "blood-alcohol" reading with little or no ethanol in his body.

This problem of nonspecificity is most noticeable in the use of infrared breath analyzing instruments, such as the various Intoxilyzer models, the Intoximeter 3000 and the BAC Datamaster. CMI's so-called "state-of-the-art" Intoxilyzer Model 5000 (and its various permutations), the most widely used breath machine in service today, utilizes infrared spectroscopy. Yet infrared analysis is particularly susceptible to giving false readings due to nonspecificity. In fact, the single greatest flaw in the Intoxilyzer itself—and the most productive area for cross-examination—is the machine's inherent lack of specificity. The technical reason for this lack of specificity is that the Intoxilyzer is not designed to detect the molecule of ethyl alcohol (ethanol), but rather only a part of that molecule—the methyl group. In other words, it is the methyl group in the ethyl alcohol compound that is absorbing the infrared light, resulting in the eventual blood-alcohol reading. Thus the machine will "detect" any chemical compound and identify it as ethyl alcohol if it contains a methyl group compound within its molecular structure. The Intoxilyzer assumes that the methyl group is a part of an ethyl alcohol compound.

The simple fact is that there are numerous compounds that contain the methyl group. Among these are isopropyl alcohol, propane, butane, propylene, methane, ethane, ethyl chloride, acetic acid, butadiene, dimethylether, dimethylamine and dimethylhydrazine. Acetone and acetaldehyde both contain the methyl group in their structure—and, interestingly, each can be found on the human breath. In fact, recent studies have found that over one hundred chemical compounds can be found on the breath at any given moment in time (see Table 1). More important, approximately 70 to 80 percent of these compounds contain methyl groups. And the infrared breath machine will detect each of these as "ethyl alcohol."

To make matters worse, the machine detects alcohol through "additive absorption." In other words, the more methyl groups the instrument detects by their absorbing the infrared energy, the higher will be the blood-alcohol reading. Thus all of the non-alcoholic compounds on the breath will have a cumulative effect—that is, the errors will be added one on top of another.

To approach this problem of specificity from another angle, ethanol has a peak absorption at approximately 3.39 microns, with the band of absorption declining rapidly on each side. However, ethanol has wide absorption bands and peaks at other wavelengths as well, such as bands in the 7.25, 9.5 and 11.0 micron range. Yet the Intoxilyzer screens out these wavelengths and attempts to identify the substance, ethanol, on the basis of only one, two, or three bands, depending on the model. This reduces the efficiency of the Intoxilyzer, since other elements besides ethanol absorb in these ranges, but few, if any, of them would also absorb in the 7.25, 9.5 and 11.0 micron ranges.

To make this point conceptually simpler, the analogy of fingerprint identification has been used. Ethanol has a "fingerprint" in that it will absorb energy wavelengths of roughly 3.39, 7.25, 9.5 and 11.0 microns. While many other substances have fingerprints that will include the 3.39 range or the 7.25 range or the 11.0 range, probably none of them will have all of them—that is, the full print of ethanol. By fingerprint analogy, then, absorption of light wavelengths at about 3.39 microns represents a single "point of identity"; absorption at several bands would represent more points of identity.

Certainly, fingerprint identification is considered more positive because there are many points of identity and, conversely, availability of only one, two, or three points of identity in finger.

 

 

Table 1
Normal Composite Compositional Profile of Human Expired Air

Printing would preclude an expert's opinion as to similarity. Yet the Intoxilyzer attempts to identify a substance on the basis of one, two, or three points of identity, despite the availability of other points that would exclude all substances other than ethyl alcohol.

How prevalent are chemicals in the breath that can register on breath analyzing machines as ethanol? There have been a number of recognized studies on the existence of chemical compounds on the breath — all concluding that a wide variety of compounds exists, including compounds containing the methyl group. The results of one such study are found in an article by Conkle, Camp and Welch entitled Trace Composition of Human Respiratory Gas, 30 Archives of Environmental Health 290 (1975). The researchers analyzed the breath of eight test subjects and found "the presence of 69 different compounds in the expired air of eight men." Id. at 292. Another article, by Krotoszynski, Gabriel and O'Neill, Characterization of Human Expired Air: A Promising Investigative and Diagnostic Technique, 15 Journal of Chromatographic Science 240 (1977), described analysis of air samples taken from 28 "average" human subjects. This study found that the "combined expired air comprises at least 102 various organic compounds of endogenous and exogenous origin." Id. at 244. The researchers further concluded that "400% of the constituents (70% of the mean organic contents) are common to 76% of the population studied." Id. at 244. Finally, Canadian scientists have reported that "approximately 200 compounds have been detected in the human breath." Manolis, The Diagnostic Potential of Breath Analysis, 29(1) Clinical Chemistry 5 (1983).

This last study confirmed the presence of acetone on the breath in diabetics and in persons on a diet "associated with a weight reduction of about one-half pound per week." Id. at 9. Another study has confirmed that diabetics may give false indications of intoxication. In Brick, Diabetes, Breath Acetone and Breathalyzer Accuracy: A Case Study, 9(1) Alcohol, Drugs and Driving (1993), a researcher found that expired ketones in the breath of an untreated diabetic can contribute to erroneously high breath-alcohol readings. Further, the acetone on the breath from ketoacidosis will result in an odor of alcohol. Finally, behavioral patterns of a diabetic whose blood-sugar level has dropped will include slurred speech, slow gait, impaired motor control, fumbling hand movements and mental confusion—all symptomatic of intoxication.

Acetone may also be found on the breath of perfectly normal, healthy individuals. Yet, acetone is one of the compounds that will be detected on many breath analyzing instruments as ethanol. In the Intoxilyzer, for example, it is detected because acetone absorbs infrared energy in the 3.38 to 3.40 micron range—the same range where ethanol is found. Therefore, if acetone were introduced into the Intoxilyzer, the machine would simply register the presence of alcohol despite its absence. If an individual had 525 micrograms per liter of acetone in the breath, he would register a blood-alcohol level of .02 to .03 percent. Thus, if an individual with a true blood-alcohol level of .08 percent had that amount of acetone, the Intoxilyzer would register in the area of .l0 to .11 percent.

The National Highway Traffic Safety Administration has published a report entitled The Likelihood of Acetone Interference in Breath Alcohol Measurement (DOT HS—806-922). The report basically summarizes scientific literature on the subject, concluding that normal individuals have insignificant levels of acetone on their breath. The data indicated, however, that dieters can have higher levels and that diabetics not in control of their blood-sugar had levels hundreds or even thousands of times higher than normal. Unfortunately, the authors did not determine what effect such levels would have on a breath testing device; they simply concluded that at levels rendering the individual "not too ill to drive," the breath reading would be raised by only .01-.02 percent. The authors (and it must be recognized that this federal agency has been consistently law enforcement-oriented, to the point of suppressing unfavorable results of radio frequency interference tests, for example) also conclude that the only instrument significantly affected by acetone interference is the Intoxilyzer 4011A.

By contrast, a more scientific article entitled Excretion of Low-Molecular Weight Volatile Substances in Human Breath: Focus on Endogenous Ethanol, 9 Journal of Analytical Toxicology 246 (1985), has concluded that acetone can exist in some normal individuals in quantities that can create falsely high results in a breath-alcohol test. For a study confirming the effects of increased levels of acetone in dieters, see Frank and Flores, The Likelihood of Acetone Interference in Breath Alcohol Measurement, 3 Alcohol, Drugs and Driving 1 (1987). In that study, researchers found that fasting can increase acetone to levels sufficient to obtain readings of .06 percent on breath testing instruments.

Similarly, a study confirming the effects of acetone in diabetics can be found in Mormann, Olsen, Sakshaug and Morland, Measurement of Ethanol by Alkomat Breath Analyzer; Chemical Specificity and the Influence of Lung Function, Breath Technique and Environmental Temperature, 25 Blutalkohol 153 (1988). Diabetic subjects in that study also were found to have acetone levels sufficient to produce breath-alcohol readings of .06 percent.

Another major source of nonspecific detection in various methods of blood-alcohol analysis involves the presence in the body of acetaldehyde. Acetaldehyde is a chemical by-product in the body's metabolism of ethanol. As the ethanol is oxidized, or "burned off," acetaldehyde is produced; eventually, the acetaldehyde is converted to carbon dioxide and water.

This oxidation of alcohol with its attendant production of acetaldehyde takes place primarily in the liver. However, it can also occur in other tissues and fluids of the body—most notably in the lungs. And, since acetaldehyde, like acetone, will be "detected" as ethanol in many types of analysis, a falsely high blood-alcohol reading can result. This nonspecific detection of acetaldehyde in the breath is particularly noticeable in infrared spectroscopy, "wet chemical" analysis and blood analysis using the oxidation technique.

In the past, this production of acetaldehyde has not been seen to be a problem. When acetaldehyde is produced in the liver, it is sent into the blood and then into the lungs in small quantities. More recently, however, it has been discovered that alcohol is metabolized—and acetaldehyde produced—in the lungs themselves. The result can be a highly elevated amount of acetaldehyde in the lungs, with a subsequently large amount in the expired breath to register in a breath analyzing instrument as ethanol.

This phenomenon of production of acetaldehyde in the lungs was commented on in a study by Jauhanen, Baraona, Hiyakawa and Lieber, entitled Origin of Breath Acetaldehyde During Ethanol Oxidation: Effect of Long-Term Cigarette Smoking, 100 Journal of Laboratory Clinical Medicine 908 (1982). The researchers discovered that the amount of acetaldehyde in the lungs was considerably greater than the amount that would be expected if passed from the liver by way of the blood into the lungs. Furthermore, the elevated amounts of acetaldehyde in the lungs were not predictable—they varied according to the individual. Thus, for example, it was found that acetaldehyde concentrations in the lungs were far greater for smokers than for nonsmokers. Translated into practical effect, smokers are more likely to have high blood-alcohol readings, regardless of their true blood-alcohol level.

In a subsequent study, it was found that breath acetaldehyde levels were found to indicate blood-alcohol levels 30 times higher than would be expected from direct blood analysis. Stowell, et al., A Reinvestigation of the Usefulness of Breath Analysis in the Determination of Blood Acetaldehyde Concentration, 8(5) Alcoholism: Clinical and Experimental Research 442 (1984). The conclusion of the researchers was, again, that the acetaldehyde in the lungs was not coming from the liver by way of the blood, but was being produced in the lungs themselves and exhaled in much larger quantities than would be expected. End result: falsely high breath test readings.

Another example of variances in acetaldehyde levels that can compound blood-alcohol analysis was reported by researchers studying alcoholics. In Lindros, et al., Elevated Blood Acetaldehyde in Alcoholics and Accelerated Ethanol Elimination, 13 (Supp. 1) Pharmacology, Biochemistry and Behavior 119 (1980), scientists discovered that acetaldehyde in the breath and blood of alcoholics was 5 to 55 times higher than that in nonalcoholics. Thus increased acetaldehyde—and consequent falsely high blood-alcohol readings—can be attributed to the makeup of the alcoholic's physiology. Of course, counsel should consider the risks in bringing this information out for the jury to ponder.

Thus it clearly appears that acetaldehyde is produced in the lungs themselves. With this elevated level of acetaldehyde in the lungs, there will be elevated levels in the breath. And apparently every breath analyzing device but those employing gas chromatography is fully capable of registering this compound as ethanol. Further, blood tests utilizing the process of oxidation reaction with potassium dichromate can be affected by acetaldehyde. In their latest advertisements for the Intoxilyzer Model 5000, the manufacturer lists an acetaldehyde detector as a new option. In developing this option, the manufacturer has clearly acknowledged the often-denied problem of acetaldehyde interference. Whether the device is effective is, of course, another matter. Certainly, counsel confronted with a case involving the Model 5000 should determine whether the option was present; if not, that fact should be pointed out to the jury. In fact, the existence of such a device in this "state-of-the-art" instrument should be interesting to a jury in DUI cases involving any type of breath testing apparatus.

It is also interesting to note that the commonly observed symptoms of flushed face and bloodshot eyes are physiologically the result of the effects of acetaldehyde—not of alcohol itself. Thus such symptoms may actually tend to corroborate the falsity of a blood-alcohol test—that is, elevated acetaldehyde evidenced by a flushed face and bloodshot eyes may have caused the high breath test reading!

An interesting study involving the Intoxilyzer 4011-AS has shown dramatically the dangers of nonspecificity. In an article appearing in 7(4) Drinking/Driving Newsletter 3 (February 19, 1988), a test conducted by the Demers Laboratory in Springvale, Maine, is described wherein a subject was tested after exposure under realistic field conditions to paint and glue. The subject entered a test room and applied a pint of contact cement to a piece of plywood; he then applied a gallon of oil-base paint to a vertical surface. This activity lasted about one hour.

Twenty minutes after leaving the room, the subject was tested on the Intoxilyzer. Results? Despite the subject's having no alcohol in his body, the machine registered .12 percent—over the legal limit. The subject was tested again one-half hour later: Readings of .05 and .04 percent were obtained.

Another example of commonly encountered chemical compounds that can affect breath tests was described in a study reported in Giguiere, Lewis, Baselt and Chang, Lacquer Fumes and the Intoxilyzer, 12 Journal of Analytical Toxicology 168 (1988). Scientists performed tests on a professional painter who was exposed to lacquer fumes under controlled conditions. In the first test, he sprayed paint in a room for 20 minutes, wearing a protective mask; his blood and breath were then tested. Although the blood test showed no presence of alcohol, an Intoxilyzer 4011-AS indicated a reading of .075 percent BAC.

Ten minutes later, the painter sprayed the same room for five minutes—but this time without the protective mask. The blood test again showed no BAC. The Intoxilyzer, however, registered a reading of .48 percent! Perhaps most interesting, the Intoxilyzer was equipped with an acetone detection light designed to detect the presence of any interfering compounds — yet at no time during the test did the light indicate the presence of any such compounds.

In an article appearing on the front page of the August 24, 1988, edition of the Spokane Spokesman Review, an individual in a Sandpoint Idaho jail awaiting trial for drunk driving claimed that he had been siphoning gasoline; when he sucked on the hose, he swallowed some of the gasoline, which later caused a high reading on a breath test. He managed to talk the sheriff into a demonstration to prove his story. Taken from his cell after one week of incarceration, he swallowed a cup of unleaded gasoline; after various periods of time, he blew into an Intoximeter.

The results? After 5 minutes, the reading was .00 percent; after 10 minutes, .04 percent; after 20 minutes, the machine registered .31 percent; and after one hour, the reading was .28 percent. Three hours after ingestion, the individual still blew a .24 percent on the Intoximeter! A quick call to a gasoline distributor confirmed that gasoline contains no alcohol.

This phenomenon has been scientifically verified in a study conducted by CMI, the manufacturer of the Intoxilyzer and reported in 8(3) Drinking/Driving Law Letter 6 (1989). The CMI technicians mixed a simulator solution of 800 micrograms of gasoline with 500 milliliters of distilled water, then introduced it into an Intoxilyzer 5000. The solution produced readings of .619 percent, .631 percent and .635 percent.

Diethyl ether is yet another substance that will be falsely detected as "alcohol" by breath testing instruments. The compound, which can be inhaled, is found in some automotive products and is used in the manufacture of plastics and smokeless gunpowder. See Bell, et al., Diethyl Ether Interference with Infrared Breath Analysis, 16 Journal of Analytical Toxicology (1992), for a study that concluded that ''[t]he possibility of interference with an alcohol reading by ether or by other substances may therefore render prosecution more difficult, if not impossible."

In another study, researchers discovered that three other compounds found in common products falsely registered as ethyl alcohol on the machines. Cowan, et al., The Response of the Intoxilyzer 4011ASA to a Number of Possible Interfering Substances, 35(4) Journal of Forensic Sciences 797 (1990). One of the substances, methyl ethyl ketone, is used in lacquers, paint removers, cements and adhesives, celluloid and cleaning fluids. Another, toluene, is used in paints, lacquers, varnishes and glues. The third is isopropanol, commonly known as rubbing alcohol.

Phil Price, a nationally prominent DUI attorney in Montgomery, Alabama, conducted a series of experiments in which subjects ingested various foods and were then tested on an Intoxilyzer 5000 (64-series). Interestingly, bread caused the highest readings! Using alcohol-free subjects, Price consistently obtained readings in the area of .05 percent after consumption of various types of bread products. Further, the slope detector failed to detect any interferent during the tests.