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The Problems With Portable Breath Tests (by DaytonDUI)

Dayton DUI Attorney Charles Rowland > DUI Law  > The Problems With Portable Breath Tests (by DaytonDUI)

The Problems With Portable Breath Tests (by DaytonDUI)

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In possibly the best article you will ever read on portable breath testing, DUI attorneys Justin McShane and Josh Lee describe the portable breath test devises which are used by the Ohio State Highway Patrol as a “potentially dangerous, non-specific and non-selective measures at roadside.”  You can find the article HERE and in the Voice for the Defense.

The Problems of Fuel Cell Devices

1.1. Lack of Specificity20 for Ethanol

As PBTs are used for purportedly forensic purposes, their specificity for ethanol becomes a critical factor. The electrochemical detector is not specific for ethanol.21 Indeed, there is “much evidence to show” they are actually not specific for ethanol.22 Garriott’s Medicolegal Aspects of Alcohol lists methanol, isopropanol, n-propanol, and acetaldehyde as other alcohols that fuel cells can respond to in addition to ethanol.23 Other studies have also found fuel cells reacting to substances other than ethanol.24

A. W. Jones, PhD, a renowned toxicologist, reports that fuel cells will respond to compounds that contain the hydroxyl group, other than ethanol.25 In a later study, Jones again found that the fuel cell is not specific to ethanol and that other alcohols and aldehydes will also oxidize in the fuel cell.26 This is important because it has been found that in the alcohol family there are over 1,500 chemical compounds that are not found in alcoholic beverages.27 Moreover, it is claimed that ketones such as acetone are not detected by the fuel cell as they are with infrared devices.28 Interestingly, there is at least one documented case where a driver has tested over the legal limit for ethanol, due to acetone, when the driver had no ethanol in his system.29 The fuel cell device used on the stop had falsely reported isopropanol as ethanol.30 The individual had latent diabetes and had been fasting, causing acetone to be present in his system, which his body in turn reduced to isopropanol, resulting in a true false positive.31

In addition, there are documented cases of methanol being mistakenly reported as ethanol by fuel cell devices.32 Absent chromatographic separation, which PBTs do not employ, distinguishing ethanol from methanol is an extremely difficult task,33 if not an impossible one. Of import is that when a PBT detects ketones and hydrocarbons, it can mistakenly report them as ethanol and add to the breath alcohol concentration.

Further proof of the apocryphal nature of the manufacturers’ claims that these devices will not react to anything other than alcohol is documented on YouTube by one of the authors of this paper, Justin J. McShane, F-AIC, JD. The recording shows a .046 g/210L breath reading on an Intoximeters FST PBT, while free of ethanol and eating ordinary white bread.34 In addition to white bread, there are other cases of a fuel cell device falsely reporting milk, soda pop, and cigarette smoke as ethanol.35 Toothpaste (specifically Sensodyne) that contains Sorbitol, a type of alcohol, registers as ethanol on a fuel cell device.36 This has been independently verified in testing by the Boston Herald.37

Another source of Ethanol is by sugar fermentation. This process has been found to occur naturally in the human body when yeast from breads and carbohydrates are present.38 Informal tests at DWI/DUI seminars across the United States have shown results over the legal limit (0.08 g/210L of breath) merely by chewing pizza, bread, or hot dog buns.39 Common foods and drinks have even been found to contain alcohol. Diet 7-Up contains some small amounts of ethanol, and high-energy drinks such as Monster and 180 Energy contain several times more ethanol than Diet 7-Up.40Breads, pizza, English muffins, wheat bread, and apple walnut rolls have all been found to contain both yeast and ethanol.41 See the endnotes for tables containing more detailed information about the alcohol content of various soft drinks and baked goods, and other beverages.42

1.2. Residual Mouth Alcohol (RMA)

As discussed earlier, alcohol only affects the body once it is transported to the brain by the blood. The PBT and its method assume that the breath sample and source of ethanol comes only from the deep lung or alveolar air.43 A second assumption is that there is no residual mouth alcohol (RMA). As such, we citizens interested in science must be concerned with the validity of these assumptions when testing breath samples. For there to be any measure of the true value, these key assumptions are required to be accurate.44

With the above in mind, it is well known that after drinking an alcoholic beverage, the body retains alcohol in the mucosal lining of the mouth for some time.45 When breath makes contact with mouth alcohol, then the alcohol reading will be falsely ele­vated,46 fantastically so at times. Sources of mouth alcohol include recent ingestion of an alcoholic drink, regurgitation of stomach contents, eructation of stomach gases, Gastroesophageal Reflux (GER), Gastroesophageal Reflux Disease (GERD), Laryngoesophageal Reflux (LER), Laryngopharyngeal Reflux (LPR), and use of breath freshening items.47

PBTs are not designed with RMA safeguards. They do not contain slope detectors48 that would help in detecting RMA.49Most importantly, when RMA is present, it only works one way: against the defendant, creating a falsely high ethanol content reading.50 Therefore, without these protections, PBTs have no way of distinguishing alveolar air from an inaccurate false high reading caused by any other source. One study found that it might take up to 19 minutes for RMA dissipation.51 The same study cited another source that stood for the possibility of effects lasting for up to one hour after consumption.52

This is why deprivation/observation periods are mandated in full Evidentiary Breath Testing (EBT) schemes like the Intoxilyzer 5000 EN. Yet, at roadside, there is no such requirement. Therefore, it is best practice that a suitable deprivation/observation period be conducted at roadside to ensure the subject’s sample is only deep lung air.53 Further, it would be best practice for the officer to conduct a replicate analysis after another deprivation period to further give confidence to a PBT estimate.54

1.3. Other Factors

Carry Over: Carry over is a potential problem where a portion of a previous breath specimen remains in the PBT and is added to a subsequent estimate. As the National Highway Traffic Safety Administration has cautioned, if the air temperature is low enough, it is possible for carry over to occur in that one person’s sample remains in the PBT and carries over to the next person’s test.55 It is not difficult to see the problems this could cause when the PBT is being used on many drivers, one after another. An example of where this could be a problem is in a roadblock situation where multiple drivers are being tested or in an underage drinking event.

Radio Frequency Interference: PBTs do not have detectors to guard against interference caused by radio frequencies (RFI).56 Here, it is important to note that in Texas, EBT devices, like the Intoxilyzer 5000 EN, are required to have RFI detectors by the Texas Department of Public Safety Breath Alcohol Testing program. Absent an RFI detector, an officer will not know when RFI interference occurs because electric fields are not detectable by the five human senses.57 One manufacturer even cautions officers to avoid “environments with high levels of radio interference or magnetic fields.”58For the patrol officer, there are plenty of sources of RFI—e.g., hand-held and vehicle mounted radio transmitters, cell phones, CB radios, light bars, in-car video, computer terminals with internet link inside the patrol vehicle, and police radar.59

Independent Sources of Variation: These include the traditional metrological concerns of calibration and bias of the device itself, and variations in taking of the breath sample: temperature fluctuations, physiological differences of individuals, and phase of ethanol metabolism to name a few.60 Most police agencies do not perform routine or preventive calibration or verification checks for these PBTs during the entire period of their deployment in the field. If the police agencies do perform calibration or verification checks, the efforts are typically not validated or well designed.

Ohio Law On Portable Breath Testing

Ohio’s Fourth District Court of Appeals slam the use of portable breath test devices as trial evidence in State v. Shuler, 168 Ohio App.3d 183, 2006-Ohio-4336.  The unique facts of this case were that the defendant was stopped on November 6, 2004 for making an erratic, improper turn.  He was “asked” to leave the vehicle for submission to field sobriety tests.  In addition, the officer administed a portable breath test to the defendant.  The PBT result was .078 (below the legal limit).  The defendant was arrested and taken to the station where the results of the BAC test were .126.

Shuler argued for admission of the PBT test as evidence.  The trial court denied the PBT’s admission saying that the PBT devise and technology are not sufficiently reliable to be used as evidence.  This should be viewed as perverse since the very same technology is often used by the courts as a basis for probable cause.  See State v. Coates, Athens App. No. 01CA21, 2002-Ohio-2160, 2002 WL 851765 and State v. Gunther, Pickaway App. No. 04CA25, 2005-Ohio-3492, 2005 WL 1594836.

The court stated, “PBT devices are not among those instruments listed in Ohio Adm. Code 3701-53-02 as approved evidential breath-testing instruments for determining the concentration of alcohol in the breath of individuals potentially in violation of R.C. 4511.19. PBT results are considered inherently unreliable because they may register an inaccurate percentage of alcohol present in the breath, and may also be inaccurate as to the presence or absence of any alcohol at all. See State v. Zell (Iowa App. 1992), 491 N.W.2d 196, 197.  PBT devices are designed to measure the amount of certain chemicals in the subject’s breath.  The chemicals measured are found in consumable alcohol, but are also present in industrial chemicals and certain nonintoxicating over-the-counter medications.  They may also, appear when the subject suffers from illnesses such as diabetes, acid reflux disease, or certain cancers. Even gasoline containing ethyl alcohol on a drivers clothes or hands may alter the result.  Such factors can cause PBTs to register inaccurate readings such as false positives. See Tebo, New Test for DUI Defense: Advances in Technology and Stricter Laws Create Challenges for DUI Lawyers, Jan. 28, 2005, www.duicentral.com/aba_journal/.  This lack of evidential reliability provides a basis for excluding PBT results from admissibility at trial.  See Elyria v. Hebebrand (1993), 85 Ohio App.3d 141, 619 N.E.2d 445; State v. Kerns (1998), Van Wert App. No. 15-97-8, 1998 WL 142384.

Wow, but they are still good for probable cause determinations?!?  That is like saying that we won’t allow the use of a psychic in court because it is hooey, but we will allow the officer to use a psychic in determining probable cause to place you under arrest and forever change your life.  If you find yourself facing a DUI/OVI charge please contact someone who is familiar with the fuel cell technology and its unreliability as an indicator of alcohol impairment.  DUI attorney Charles M. Rowland II dedicates his practice to defending the accused drunk driver in Fairborn, Dayton, SpringfieldKetteringVandaliaXeniaMiamisburgHuber HeightsBeavercreekCentervilleSpringboro, Franklin and throughout Ohio.  He has the credentials and the experience to win your case and has made himself the Miami Valley’s choice for DUI defense.  Contact Charles Rowland by phone at 937-318-1DUI (937-318-1384), 937-879-9542, or toll-free at 1-888-ROWLAND (888-769-5263).  For after-hours help contact our 24/7 DUI HOTLINE at 937-776-2671.  For information about Dayton DUI sent directly to your mobile device, text DaytonDUI (one word) to 50500.  Follow DaytonDUI on Twitter @DaytonDUI or Get Twitterupdates via SMS by texting DaytonDUI to 40404. DaytonDUI is also available on Facebook,www.facebook.com/daytondui and on the DaytonDUI channel on YouTube.  You can also email Charles Rowland at: CharlesRowland@DaytonDUI.com or write to us at 2190 Gateway Dr., Fairborn, Ohio 45324.


Charles Rowland


Charles M. Rowland II has been representing the accused drunk driver for over 20 years. Contact him at (937) 318-1384 if you find yourself facing a DUI (now called OVI) charge.

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