Evaluation of the Intoxilyzer® 9000 evidential breath alcohol testing instrument

Abstract

The Alcohol Test Committee (ATC) of the Canadian Society of Forensic Science sets out equipment standards and evaluation procedures for the evaluation of breath testing equipment in Canada. The Intoxilyzer® 9000 was evaluated according to the 2014 Equipment Standards and Evaluation Procedures with results demonstrating that the instrument met, or exceeded, the requirements of the ATC on all criteria including accuracy, linearity, precision, and acetone interference. Human subject testing provided a comparison of blood alcohol concentrations (BACs) determined by the Intoxilyzer® 9000 with near-simultaneous breath test results from an Intoxilyzer® 8000C, an Approved Instrument in Canada since 2007. The results of 50 paired breath samples on 10 drinking subjects were well-correlated (R2 = 0.966) and described by a linear model, y = 0.95x + 0.84. The validation of the Intoxilyzer® 9000 according to the standards of the ATC demonstrates the instrument to be an accurate and reliable means of determining breath alcohol concentrations over a range of forensically relevant BACs. The Intoxilyzer® 9000 was added to the Approved Breath Analysis Instruments Order in 2019 identifying it as suitable for the purposes of Section 320.14 of the Criminal Code of Canada.