Smoking or Vaping

Their effect on breath alcohol readings

Counterpoint Volume 7: Issue 2 - Article 5 (August 2023)

An article for participants in the myCAMprogram

Jan Semenoff, BA, EMA
​Forensic Criminalist

Article information:

1170 words (approximately 6-8 minutes)
What are the effects when your client was smoking a cigarette (or worse, an e-cigarette) when they were stopped by the police? Perhaps just a few minutes elapsed from the time of smoking until the first breath test. Residual tobacco or e-liquid residue would be present in their mouth during the roadside Preliminary Breath Test. Would there be enough time for the residual tobacco residue in their mouth to dissipate? What effects are caused by that contamination?

The Necessity of a Deprivation & Observation Period on the Readings Obtained

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 all sources of residual contamination. 
​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 recent consumption, or use of, any substances. Any of these sources of contamination, including residual tobacco contamination, may falsely elevate the reported BrAC 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, the test results obtained are unreliable, as they may be falsely elevated with contamination. 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 contamination in the mouth. For tobacco residue, a minimum deprivation of five-minutes is required. If this is not properly performed, the results may be falsely inflated, and significantly so.

The Effect of Mouth Contamination on a Breath Test

We've addressed issues of Mouth Contamination in previous Counterpoint articles:
  • An Introduction to Breath Test Error Messages: Part 1
  • Breath Testing Error Messages: Part 4
  • Residual Alcohol Detection Systems - Part 2
  • The Dissipation of Fresh Mouth Alcohol and its Effect on Breath Alcohol Readings
  • Chewing Tobacco & Breath Alcohol Testing Issues
​The key to obtaining two suitable samples revolves around a proper observation and deprivation period with a mouth free of contaminants. This is particularly important with Preliminary Breath Test (PBT) Devices that do not employ the more sophisticated safeguards of Evidentiary Breath Testing equipment. 
Tobacco Residue
​Any recent smoking would introduce potential contamination into the oral pathway in the form of tobacco residue. This must be both rinsed away and given time to dissipate. If the rinsing and time for dissipation is denied, then the reading obtained will be elevated beyond the true blood alcohol concentration. False positives associated with oral contamination are not at all detected by fuel cells used in ADSs, regardless of the manufacture of the device.
​It has been known since the early days of breath alcohol testing that tobacco residue could provide contamination that increased a true BAC reading beyond its actual value. Early evidentiary units such as the Breathalyzer 900A and Approved Screening devices such as the ALERT J3-A were prone to false positives from tobacco residue. The ALERT J3-A utilized a semi-conductor sensor that was highly susceptible to tobacco residue false positive results (Bray & Huntley, 1974; Smith, 2003). The later developed fuel cell devices were also susceptible to the effects of tobacco residue (ibid).
From a pragmatic point of view, the tar-like residue from exhausted cigarette smoke deposited into the fuel cells sample chamber, and onto the reactive surface of the fuel cell itself, is damaging to the device, reducing its longevity and reliability.
​University of Iowa researchers identified the effects of tobacco residue on fuel cell devices and concluded that evidence of smoking could be detected for 30-60 minutes on a fuel cell device after smoking a cigarette (Haverhals and Leddy, 2006). They found that the reading obtained on a fuel cell device was falsely enhanced due to the presence of the cigarette residue. Note that it is NOT necessary for active cigarette smoke to be exhaled into the breath testing device for the false positive readings to occur.
​In Canada, the national training standard employed by the Royal Canadian Mounted Police (RCMP) for Intoximeter Alco-Sensor FST operators includes instruction on test subjects who were smoking. The training standards require that a breath test shall not be conducted until five-minutes after smoking.
Additionally, internal RCMP correspondence indicates that false positive readings were generated by tobacco smoke with the Intoximeter Alco-Sensor FST. Readings as much as 0.032 g/dL were added to the true BrAC value of the test subject. The effect was transient – disappearing according to their preliminary findings within 30 seconds or so after smoking. As such they identified that “cigarette smoke is causing a reaction on the fuel cell surface”. They felt a five-minute deprivation period before breath alcohol testing was enough to prevent the false positive effects.
E-Cigarettes 
​E-cigarettes create an aerosol, often called vapor or simply “vape”, made of particulate matter. The vapor regularly contains a variety of chemicals, including propylene glycol, glycerin, nicotine, chemical flavoring agents, and traces of nitrosamines, with other toxicants, carcinogens, heavy metals, ethanol, and metal nanoparticles. 
Their exact composition varies and depends on a variety of circumstances. Due to the varied and numerous compositions of electronic cigarette aerosols, the deprivation period precautions employed with traditional cigarettes are of increased importance.
Ethanol in E-Liquids, but Not Listed as an Ingredient​
Researchers at the Virginia Commonwealth University tested 56 commercially available e-liquids (the stuff used to vape in an e-cigarette) used in electronic cigarettes in the US between 2012 and 2016. Only one of the manufacturers listed ethanol as a component of the e-liquids, yet headspace gas chromatography analysis showed that ethanol was detected in 95% (53/56) of the products. Their measured concentration ranged between 0.00007 to 0.206 grams/mL of ethanol.

Read their study:
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630485/pdf/nihms868789.pdf
​Certainly, there have not been any published studies looking at the effects of the contamination of the inhaled ethanol on breath test devices, but it stands to reason that contamination occurring within the five minute boundary would create a false positive effect. Keep in mind, the Canadian RCMP determined the false positive result was as high as 0.032 g/dL with regular cigarettes that contain no ethanol. E-cigarettes, with their e-liquids containing a hidden but measurable ethanol content, would create a higher reading.
​Ultimately, if a test subject is not afforded a proper deprivation period, nor are they allowed or required to rinse their mouth with fresh water, contamination caused by the recent smoking could potentially cause a false-positive bias in the resulting breath alcohol reading. Rudimentary PBTs incorporating a simple fuel cell, with no built-in safeguard to prevent any false-positive readings from residual tobacco or e-liquid residues, may be adversely affected.
​As a result, the BrAC readings could reflect the combined effects of any alcohol in the test subject’s system and the oral contamination. Without proper rinsing and a wait period before breath sample provision, the testing is performed under sub-standard conditions, and gives rise to sub-standard results.
​Practice Tip:
Always include use of cigarettes, e-cigarettes and chewing tobacco in your client questionnaire. When was the last time they used that product?

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For further study:

  1. Alco-Sensor FST® Operator Course, Course Training Standard, Royal Canadian Mounted Police, 2014.
  2. Alco-Sensor FST® Instructor Course, Course Training Standard, Royal Canadian Mounted Police, 2014. 
  3. Bray, K. and Huntley, M. S., Breath Measurement Instrumentation as Alcohol Safety Interlock Systems, Interim report for the United States Department of Transportation, National Highway Traffic Safety Administration, HS 506/R5403, March 1974.
  4. Dubowski, K.M., Quality Assurance in Breath-Alcohol Analysis, Journal of Analytical Toxicology, Vol. 18, Oct 1994.
  5. Dubowski, K.M., Acceptable Practices for Evidential Breath-Alcohol Testing, Center for Studies of Law in Action, Borkenstein Course Materials, Indiana University, May 2008.
  6. Fuel Cell Smoke Effects, Internal memo from RCMP Forensic Specialist Kimberly Young to Melanie Brisson, 2016 Sept 13 at 0805 hours. Obtained from disclosure.
  7. Gullberg, R.G., The Inadequacy of Instrumental “Mouth Alcohol” Detection Systems in Forensic Breath Alcohol Measurement, Northwest Association of Forensic Sciences, Oct. 2000.
  8. Gullberg, R. G., Breath Alcohol Measurement Variability Associated with Different Instrumentation and Protocols, Forensic Science International 131 (2003) 30-35.
  9. Haverhals, L., and Leddy, J., Breath-Based Electrochemical Sensors: Simultaneous Determination of Ethanol and Smoking B-Products, Meeting Abstract from the Electrochemical Society, MA2006-02 699, 2006. 
  10. Jones, A. W., Concerning Accuracy and Precision of Breath-Alcohol Measurements, Clinical Chemistry, 33/10, 1701-1706 (1987).
  11. Poklis JL, Wolf CE, Peace MR., Ethanol Concentration in 56 Refillable Electronic Cigarettes Liquid Formulations Determined by Headspace Gas Chromatography with Flame Ionization Detector (HS-GC-FID). Drug Test Anal. 2017 Oct; 9(10):1637-1640. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630485/pdf/nihms868789.pdf
  12. Semenoff, J., Breath Testing Error Message, Part 4 – Invalid Samples, Counterpoint, Volume 2, Issue 4; Article 2, Spring 2018.
  13. Semenoff, J., The Importance of the Wait, Deprivation or Observation Period, Counterpoint, Volume 3, Issue 1; Article 1, Fall 2018.
  14. Sterling, K., The Rate of Dissipation of Mouth Alcohol in Alcohol Positive Subjects, The Journal of Forensic Science, 2011.
  15. Swift, R., Direct Measurement of Alcohol and its Metabolites, Addiction, 98 (Suppl. 2), 73-80, 2003.