Duplicate breath tests are a well known safeguard for increasing confidence in breath alcohol tests. Kurt Dubowski authored a paper in1960 entitled “Necessary Scientific Safeguards in Breath Alcohol Analysis” and was published in the Journal of Forensic Sciences, 5: 422-433, 1960. Although it was published fifty three years ago, it still reads fresh and has relevance for today’s breath testing community: “As a final general observation, it may be noted that, as in other phases of chemical analysis, justifiable confidence in breath alcohol analysis results can be drastically increased by the relatively simple and practical means of performing duplicate or replicate analyses on a given subject in rapid succession. This technique of increasing the certainty of the result, in fact, exploits three of the major advantages of breath alcohol tests: rapid, simple and non-traumatic sampling, relative simplicity of the analysis and rapidity of the complete analysis. 

Twenty-six years later, in 1986, Dubowski repeated the necessity of duplicate breath alcohol testing when he reported the position statement of the National Safety Council Committee on Alcohol and Other Drugs (WOA30116): “At least two separate breath samples should be collected and analyzed individually in performing any quantitative evidential breath-alcohol analysis. The breath samples should be collected at intervals of not less than 2 nor more than 10 minutes after an initial deprivation period of at least 15 minutes.” And here we are. Another twenty-seven years after Dubowski’s second position statement and a full fifty three years after Dubowski’s original paper duplicate breath tests are still a much better safeguard against mouth alcohol, solvent inhalation, and rare, random errors such as RFI that may affect ONE breath test. Even new technology such as slope detectors cannot provide the same level of confidence as the simple act of duplicate breath testing. In spite of this, there are still jurisdictions (mainly in the USA), that do not require mandatory duplicate breath tests. With that said, most of the Western World (inter alia, UK, Canada, Sweden, New Zealand, Australia) has adopted duplicate breath testing and approximately 2/3rd of the United States do likewise as part of their scientific safeguards.

QualityAssurance in Breath-Alcohol Analysis*

by Kurt Dowbowski, PhD., LL.D., DABCC, DABFT

The University of Oklahoma Health Sciences Center, Department of Medicine and Forensoc Sciences Laboratories, P.O. Box 26901, Oklahoma City, OK 73190 and Office of the State Director of Tests for Alcohol and Drug Influence State of Oklahoma 


DUIstopped.US strongly encourages and recommends that all states adopt mandatory duplicate breath alcohol testing as a simple procedural change that will improve, substantially, the reliability and scientific validity of their breath alcohol testing programs. Change.org petition to require every state to pass mandatory standardized breath testing practices. >Example of DUIstopped.us Change.org Petition that will be on line Jan. 21, 2014: 


The lack of transparency in breath testing creates doubt as to the scientific reliability and accuracy of any result from all breath test machines.” One of the flaws, one of the deficiencies in our current alcohol programs is that all breath test machines have the capability of retaining and reporting more data than the states have chosen to retain. Some states retain and report greater amounts of data than other states. The problem by not retaining and reporting all the data comes back to that very general premise, ‘The validity results is only as good as the amount of information available to substantiate those results. So if the information is limited, it doesn’t really tell the public, the courts and the juries the truth.


No forensic computerized machine [...] can ever overcome or replace the integrity of its human caretakers and operators.

Due Process of Law does not allow the Court to place before a Jury, evidence gathered under such troubling circumstances [...] in a criminal trial.

To allow anything less would critically undermine the public's confidence and trust in their criminal justice system.

The Honorable Lee J. Seidman
County Court Judge, 17th Judicial Circuit
State of Florida v. Richard Medina, Case No: 07-28236mm104

* The Intoxilyzer 8000 breath test machine is the # choice for states and law enforcement and is currently used in over 20 states in the USA.

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*SELLER HEREBY EXPRESSLY DISCLAIMS ANY IMPLIED STATUTORY WARRANTY OF MERCHANTABILITY OR FITNESS FOR PARTICULAR PURPOSE.*

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Motion to End Breath Testing in Pennsylvania  Comes on the Heels of the Ruling in Commonwealth v Schildt

In a latest development, The McShane Firm has motioned to have breath testing banned in the state of Pennsylvania. This comes on the heels of the ruling of Dauphin County Judge Lawrence F. Clark in the case of Commonwealth v Schildt (complete ruling).

Attorney McShane has asked the court to dismiss all current Pennsylvania DUI cases involving breath testing as well as re-opening all such cases that have occurred in the past year and 90-days.

This step comes after it revealed that the manufacturer of the Intoxilzyer 5000EN, CMI Inc. not compliant with state regulations. In his ruling in Commonwealth v Schildt, Judge Lawrence F Clark, Jr. writes, “However, notwithstanding any such “verifying” undertakings performed by the manufacturer (CMI) on its own gas chromatograph, the bare FACT remains that the entity (CMI) that is performing the initial calibration of the breath testing device is using a simulator solution which was prepared (and allegedly subjected to some sort of a gas chromatographic analysis) by the same manufacturer and calibrator of that device. The regulatory requirement of a “gas chromatographic analysis by a laboratory independent of the manufacturer” has been blatantly ignored and obviously violated.

This means that the reading from the Intoxilyzer 5000EN breath machine is no longer considered reliable. Judge Lawrence F Clark, Jr. writes in his opinion, “As a result of the evidence produced at the hearing, it is now extremely questionable as to whether or not any DUI prosecution which utilizes a reading from an Intoxilyzer 5000EN breath testing device could presently withstand scrutiny based upon the startling testimony of the commonwealth’s own witness, Mr. Faulkner, at the hearing,” wrote in his opinion in the Schildt case.

If granted, this motion could affect tens of thousands cases statewide according to McShane.


If you need legal assistance or advice, consult a lawyer in your state. None of the information on this page represents the opinion or views of the DUIStopped.us.