Principles And Pitfalls in Alcohol Toxicity, Part 4

Drugs & AlcoholApplying Breath Alcohol to Blood Alcohol Contents

There are several methods by which breath alcohol is determined.

The BAC Data Master

This instrument analyses breath sample using of infrared absorption in the 3.4 micron infrared band with the raw data being processed by 2 or 3 narrow band filters within this region.

BAC Verifier Data Master

This method is designed primarily to meet the State of Washington requirements for a breath testing device. The Verifier uses the same system to analyze a breath sample, but includes a number of additional technical features which includes a printer, adding a new central processing unit to inhibit electrical interference, changes in the formula used to calculate the presence of acetone in a breath sample. Prior to the use of the Data Master, it was found that while this unit may be able to accurately and precisely measure the ethanol concentration, absolutely no information was obtained as to whether or not the Data Master can specifically measure alcohol (and only alcohol) contained in a human breath sample, and to be able to differentiate from acetone in the exhaled air from the lung. Furthermore, the State performed no test to compare the individuals’ breath alcohol sample with a corresponding blood sample taken at or about the same time. Therefore some questions may be raised in regards to 100% reliance on this method only, for forensic purposes. Currently there are several published research papers, peer reviewed, evaluating the capabilities of the BAC Data Master. The papers conclude that when compared to a mechanical simulator the human body has a sizable biological variability, and in any given human breath test there exists a statistically significant possibility of the breath testing devise registering an erroneously high or low result, based on the biological variability of the human subjects.

The infrared method detects other metabolites in exhaled lung air and cannot absolutely distinguish between ethyl alcohol and other metabolites and therefore, has the potential of giving erroneous readings. Several papers have looked into the suitability of the breathalyzers. The overall assessment was that the majority of breath test machines will potentially erroneously detect other metabolites in the exhaled air. For instance, acetone in the exhaled air will be registered by infrared as alcohol and their reliance on breath analysis only for forensic purposes is not sufficient.

About Nachman Brautbar, M.D., F.A.C.P.

Experienced in internal medicine, toxicology, occupational medicine, alcohol, drugs, and nephrology, with a specialization in toxicology; evaluation, analysis & interpretation of urine drug/alcohol tests; drug/alcohol concentrations in the blood; findings in blood and urine samples; assessment of driving under the influence. His list of academic appointments includes Associate Professor of Pharmacology and Medicine, and Clinical Professor of Medicine at the University of Southern California, School of Medicine. Dr. Brautbar is a peer reviewer for the Department of Human Health Services, earlier Agency for Toxic Substances and Disease Registry (ATSDR). Dr. Brautbar has been on the faculty of the National Judicial College and has lectured to judges on the issue of scientific evidence. He has been a visiting professor at national and international scientific institutions and centers such as Yale, Harvard, Mayo Clinic, and NIH. Dr. Brautbar is a fellow of the Collegium Ramazzini. Dr. Brautbar has testified in the California State Senate and the United States Senate on toxic groundwater contamination.

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