Chewing Tobacco & Breath Alcohol Testing Issues
Why is this still a thing ?
Counterpoint Volume 3: Issue 3 - Article 3 (January 2019)
An article for participants in the myCAMprogram
Jan Semenoff, BA, EMA
Forensic Criminalist
This issue continues to come up again and again – and it is one worth asking your client about in all cases where the reported breath reading is inexplicably high. Did your client use chewing tobacco on the day in question? Your client may have had an active pouch of chewing tobacco, or worse, remnants of chewing tobacco debris, in their mouth when a breath sample was obtained. What are the effects? What should have occurred for a reliable breath test result?
Can mouth contamination affect a breath test?
ANY oral contamination can adversely affect the breath test results, and chewing tobacco is one of the most notorious culprits in this regard. Proper breath testing protocols dictate that all possible sources of contaminate should be eliminated prior to beginning the observation and deprivation period in order to receive breath samples that are truly suitable for analysis. This, by necessity, includes ridding the mouth of any residual chewing tobacco, and should include rinsing the mouth with fresh water.
Figure 1 - A variety of types of smokeless tobacco are available.
Personally, I’ve never really used chewing tobacco (I tried it once or twice and decided it was just not for me). However, chewing is one of the oldest methods of consuming tobacco. It remains fairly commonplace and socially acceptable today - perhaps mores considering many of the local ordinance bans on smoking tobacco in public. When asked, many test subjects relate that they had the chewing tobacco in their mouths (or had just recently spit it out just prior to) breath testing. Worse, many users of chewing tobacco actually have it in their mouths during the consumption of alcohol. In these cases, the chewing tobacco becomes saturated with ethanol, and this soaked tobacco becomes a major source of contamination, one not easily discovered, and not readily managed.
Figure 2 - Long in use, and long considered socially acceptable. There is debate as to the degree of social acceptance of "chew" created by baseball player's use of chewing tobacco during games.
|
The remedy for this contamination, however, is relatively straightforward. Remnants of chewing tobacco and its contaminated residue must be properly rinsed away in order that the breath test proceeds without the potential of false-positive bias. With the residue – again a major source of contamination - still in place, the deprivation period is rendered absolutely ineffective. If this situation has occurred with your client, the breath tests were performed under substandard conditions. We’ve discussed sub-standard acts, practices and conditions in prior articles. They generate, by definition, sub-standard results. Sub-standard as in unreliable.
|
The deprivation and observation period
You may wish to review the article "The Importance of the Wait, Deprivation and Observation Period" from Counterpoint Volume 3: Issue 1 - Article 1..
The notion of conducting a pre-breath test observation and deprivation period has been well established in breath alcohol testing protocols (Dubowski, 1985, 1991, 1994, 2008; Gullberg, 2003; Jones, 1987). Most instrument manuals and state training manuals and procedures follow a minimum 15-minute deprivation and observation period. The purpose of this deprivation and observation period is to provide a verifiable absence of possible contaminants, gagging, regurgitation of stomach contents, vomitus, burping or consumption of any substances.
The notion of conducting a pre-breath test observation and deprivation period has been well established in breath alcohol testing protocols (Dubowski, 1985, 1991, 1994, 2008; Gullberg, 2003; Jones, 1987). Most instrument manuals and state training manuals and procedures follow a minimum 15-minute deprivation and observation period. The purpose of this deprivation and observation period is to provide a verifiable absence of possible contaminants, gagging, regurgitation of stomach contents, vomitus, burping or consumption of any substances.
Any of these sources of contamination, including chewing tobacco remnants left in the mouth, may falsely elevate the reported BAC results, artificially raising a legal amount of alcohol well beyond the per se limit. Therefore, standard testing protocols mandate that the observation and deprivation period be closely and continuously observed.
If the deprivation and observation period is not conducted properly (and it won't be if there is contaminate in the mouth), the test results obtained will be unreliable, as they may be falsely elevated with the contamination. Even under ideal circumstances, studies have consistently shown the need for a period of deprivation of at least 15-20 minutes in order to allow for natural dissipation of any residual alcohol in the mouth. If this is not properly performed, the results may be falsely inflated, and will not necessarily be identified as INVALID by the Residual Alcohol Detection System.
Shouldn't a Deprivation & Observation Period prevent the contamination?
Not necessarily, in fact... probably not at all. In the case of chewing tobacco, even IF the deprivation and observation period protocols ARE followed, the contaminate will still be present unless it has been both eliminated and rinsed away. Waiting 15 or 20 minutes before the breath test is ineffective, because the chewing tobacco remnants have just been in the mouth 15 or 20 minutes before the breath test.
Not necessarily, in fact... probably not at all. In the case of chewing tobacco, even IF the deprivation and observation period protocols ARE followed, the contaminate will still be present unless it has been both eliminated and rinsed away. Waiting 15 or 20 minutes before the breath test is ineffective, because the chewing tobacco remnants have just been in the mouth 15 or 20 minutes before the breath test.
Some statistics...
A 2016 survey by the US Center for Disease Control revealed that use of smokeless tobacco products have increased among teen users, with more using chewing tobacco products than cigarettes. Many people use chewing tobacco because it is a more accessible means of intaking nicotine.
A 2016 survey by the US Center for Disease Control revealed that use of smokeless tobacco products have increased among teen users, with more using chewing tobacco products than cigarettes. Many people use chewing tobacco because it is a more accessible means of intaking nicotine.
- 6% of teenagers had used chewing tobacco at least once in the 30 days prior to the survey
- Usage was highest among young caucasian males, and more if the person is in or from a rural setting
- 3.4% of adults use smokeless tobacco products regularly (and that means it is a potential issue in 3.4% of breath test cases)
SOURCE: https://www.cdc.gov/tobacco/data_statistics/fact_sheets/smokeless/use_us/index.htm
But wait... Shouldn't the Slope Detector identify the presence of the contamination?
The Residual Alcohol Detection System (RADS or Slope Detector)
Short answer - no, it won't.
By now, Counterpoint readers should be fairly familiar with the ability of a breath alcohol device to identify contaminated samples. We've discussed the matter of the RADS or Slope Detector before. The forensically acceptable standard of obtaining two readings within 0.020 g/dL (20 milligrams/dL) of each another, coupled with an observation and deprivation period prior to, and between, the two readings assists in obtaining suitable samples. The slope detector system adds only a minor degree of validity to the testing process. The key to obtaining two suitable samples revolves around a proper observation and deprivation period with a mouth free of contaminants.
By now, Counterpoint readers should be fairly familiar with the ability of a breath alcohol device to identify contaminated samples. We've discussed the matter of the RADS or Slope Detector before. The forensically acceptable standard of obtaining two readings within 0.020 g/dL (20 milligrams/dL) of each another, coupled with an observation and deprivation period prior to, and between, the two readings assists in obtaining suitable samples. The slope detector system adds only a minor degree of validity to the testing process. The key to obtaining two suitable samples revolves around a proper observation and deprivation period with a mouth free of contaminants.
It has been my experience that the slope detector can, and often is, fooled under a variety of circumstances, including the presence of contaminating alcohol and foreign matter in the mouth. I have routinely observed the slope detector fail to register mouth alcohol that is as much as 15 minutes old, often allowing the unit to register an abnormally high reading given a simple swish of alcohol. Published studies indicate failure of the residual alcohol detection system to identify mouth alcohol bias between 37% (Harding et al, 1992) and 48% failure (Simpson et al, 2004). Gullberg (2000) also reports on the inadequacy of the mouth alcohol detection systems. Harding reported that some of these failures occurred after more than 15 minutes of deprivation. Keep in mind that these statistics are all based on testing subjects who have a mouth free of contaminates. Failure of the Slope Detector will be substantially higher when oral contamination is in place.
Figure 3 - The RADS is programmed to identify a sudden sharp drop in the BrAC reading that indicates the presence of oral contamination.
|
Remember, the RADS (Residual Alcohol Detectors) are designed to identify a sudden rise in measured BAC with a subsequent sharp drop in BAC from second to second during the breath test. False-positives associated with mouth alcohol contamination do not necessarily follow this “rise and drop” pattern, and are not easily detected by the programmed algorithms, regardless of the manufacture of the device. If the chewing tobacco or its remnants are in place, the level of the oral contamination will remain stable. There will be no rise and sudden sharp drop in the exhaled BrAC profile, and therefore, the RADS will not identify the presence of the contaminate. This will result in a falsely-elevated reported BrAC reading higher than the "true" BAC level.
Figure 4 - With no sharp drop in BrAC profile, the presence of the contamination cannot be identified by the RADS programmed algorithm.
|
Again, we’ve examined the RADS before in three previous articles. I can only conclude that the slope detectors are merely an investigative aid and are a highly unreliable detector of mouth alcohol contamination, even when NO contamination is present (detecting only a burp or belch). The Residual Alcohol Detection Systems programmed into evidentiary breath testing devices are designed to determine that false readings from mouth contamination does not occur. However, I don’t believe they are reliable enough to warrant this degree of faith. I have seen the detectors fail too often under controlled circumstances to rely upon them “beyond a reasonable doubt.”
|
If the test subject is not afforded a proper deprivation period, nor are they allowed or required to rinse their mouths with fresh water, residual alcohol absorbed and retained by the chewing tobacco will cause a false-positive bias in the resulting breath alcohol reading. As a result, the BrAC readings would reflect the combined effects of any alcohol in the test subject’s systems and the contamination. Without proper rinsing being performed, I think it is more likely than not that any reported BrAC readings are falsely inflated.
|
So, ultimately this comes down to the sub-standard act of Operator Error. The breath test operator should have examined the test subject's mouth prior to breath testing, and should have eliminated the source of contamination (including rinsing the mouth) prior to beginning a deprivation and observation period before testing occurs.
Conclusion
If we accept any stated alcohol consumption patterns as factual, we can see that the reported BrAC results obtained in cases of mouth alcohol contamination by chewing tobacco may be the result of a falsely elevated reading due to mouth alcohol bias that was not detected by the Residual Alcohol Detection Algorithm. Remnants of contaminated chewing tobacco could be present in the test subject’s mouth at the time breath samples were obtained. And, if present, the testing protocol would therefore be performed in a substandard manner, and under substandard conditions, and any results obtained should be considered inherently unreliable.
Practice Tip: |
Send me your questions or comments:
Comments and questions will be posted here with their responses:
Comments and questions will be posted here with their responses:
For further study:
- Dubowski, K.M., “Quality Assurance in Breath-Alcohol Analysis”, Journal of Analytical Toxicology, Vol. 18, Oct 1994.
- Dubowski, K.M., “Acceptable Practices for Evidential Breath-Alcohol Testing”, Center for Studies of Law in Action, Borkenstein Course Materials, Indiana University, May 2008.
- Gullberg, R.G., “The Inadequacy of Instrumental “Mouth Alcohol” Detection Systems in Forensic Breath Alcohol Measurement”, Northwest Association of Forensic Sciences, Oct. 2000.
- Gullberg, R. G., “Breath Alcohol Measurement Variability Associated with Different Instrumentation and Protocols, Forensic Science International 131 (2003) 30-35.
- Hlastala, M., Lam, W., and Nesci, J., “The Slope Detector Does Not Always Detect the Presence of Mouth Alcohol”, For the Defense, March 2006.
- Jones, A.W. and Andersson, L., “Influence of Age, Gender and Blood-Alcohol Concentration on Disappearance Rate of Alcohol from Blood in Drinking Drivers”, Journal of Forensic Science 1996; 41(6), pages 922-926.
- Jones, A.W., Jonsson, K.A. and Neri, A., “Peak Blood-Ethanol Concentration and the Time of Its Occurrence After Rapid Drinking on an Empty Stomach”, Journal of Forensic Sciences, JFSCA, Vol. 36, No. 2, March 1991, pages 376-385.
- Jones, A. W., “Concerning Accuracy and Precision of Breath-Alcohol Measurements”, Clinical Chemistry, 33/10, 1701-1706 (1987).
- Semenoff, J., “Breath testing Error Message, Part 4 – Invalid Samples”, Counterpoint, Volume 2, Issue 4; Article 2, Spring 2018.
- Semenoff, J., “The Importance of the Wait, Deprivation or observation Period”, Counterpoint, Volume 3, Issue 1; Article 1, Fall 2018.
- Sterling, K., “The Rate of Dissipation of Mouth Alcohol in Alcohol Positive Subjects”, The Journal of Forensic Science, 2011.
