Opinion ID: 1345955
Heading Depth: 2
Heading Rank: 1

Heading: Breath Testing in General

Text: Tucson, along with the majority of jurisdictions in Arizona, uses the Intoxilyzer to test blood alcohol content. In an Intoxilyzer test, the suspect blows a sample of deep-lung air through a mouthpiece and tubing into the machine, which uses a process of infrared spectroscopy to examine the amount of ethyl alcohol present in the sample and converts this into a breath alcohol concentration reading of grams of alcohol per 210 liters of breath. 2 R. ERWIN, DEFENSE OF DRUNK DRIVING § 15.02, at 15-10 (1989). Several factors can affect the accuracy of the test results: random error, radio frequency interference, mouth alcohol, [3] chemical interferants, insufficient alveolar sample, and operator error. However, Intoxilyzers have a number of mechanisms to guarantee the accuracy and reliability of test results. The Model 5000 Intoxilyzer used in these cases gives the operator step-by-step instructions. If the test is not administered correctly, the machine invalidates the test. The Model 5000 protects itself against radio frequency interference and also can detect chemical interferants. The machine can detect mouth alcohol, and invalidates the test when it is detected. Finally, the instrument will indicate that the sample is deficient if deep-lung air is not obtained. The silica gel method of breath preservation is used in conjunction with the Intoxilyzer. It utilizes a glass tube with silica gel crystals in it. Silica gel is a highly absorbent substance that attracts and captures moisture. Because the Intoxilyzer does not destroy the breath sample as it is analyzed, the same breath sample used in the state's test is blown over the silica gel upon completion of the primary test. The tube is then sealed and given to the defendant for independent analysis. The reliability of the silica gel method is disputed. See, e.g., A. Bergh, Observations on ToxTrap Silica Gel Breath Capture Tubes for Alcohol Analysis, 30 J. OF FORENSIC SCI. 186 (1985) (concluding that the Intoxilyzer is twice as accurate as the silica gel method). The state's experts testified at the evidentiary hearing that there are a number of problems that may affect the accuracy of the test. The results may be affected by undetected mouth alcohol, faulty collection, improper storage and transportation, and deficient testing procedures. The state's experts testified at the evidentiary hearing that replicate testing avoids the problems inherent in the silica gel method, as well as ruling out the possibility of random error that is present with a single Intoxilyzer test. Reporter's Transcript of Evidentiary Hearings Held April 6 and April 20, 1988 (filed Aug. 8, 1988), at 117, 138-40. The National Safety Council has recommended that all states adopt replicate testing and abandon requirements to capture second samples. Id. at 139; see also ERWIN, § 18.03.