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How Utah DUI Attorneys Challenge Breathalyzer Results

How the Intoxilyzer 8000 Works

Utah law enforcement primarily uses the Intoxilyzer 8000 for breath testing. The device measures ethanol concentration in deep lung air using infrared spectroscopy, then converts the result to a blood alcohol estimate using an assumed partition ratio of 2100:1 — the ratio of alcohol in breath to alcohol in blood.

Each of these steps introduces potential error. Each is challengeable.

The Partition Ratio Problem

The 2100:1 partition ratio is a population average. Individual partition ratios vary from approximately 1700:1 to 2400:1. A person with a ratio of 1700:1 will produce a breath test reading significantly higher than their actual blood alcohol level — not because they're more impaired, but because of individual physiology.

Why this matters at 0.05%: Utah's lower BAC limit means the margin of error in breath testing is proportionally more significant than in states with a 0.08% threshold. A reading of 0.051% that's really 0.048% due to partition ratio variation could be the difference between a DUI and no charge.

Calibration and Maintenance Records

Under Utah Administrative Code R714-500, agencies must maintain the Intoxilyzer 8000 according to specific protocols, including regular calibration checks. When we take a DUI case, we immediately request:

  • Calibration records for the specific device used
  • The last several calibration check results
  • Maintenance logs and repair records
  • Operator certification and training records
  • Solution lot records for the reference sample used during calibration

Calibration drift, failed calibration checks, and use of expired reference solutions are all grounds to challenge the admissibility of the result.

Operator Error and Protocol Violations

The Intoxilyzer 8000 must be administered following specific protocols. These include a required observation period (typically 15 minutes) before testing to ensure the subject doesn't belch, regurgitate, or introduce mouth alcohol. If this observation period isn't documented, the result is challengeable. Additional issues include improper air blank tests, radio frequency interference, and failure to confirm the subject's identity.

The Foundation Requirement Under State v. Vialpando

Utah courts require a three-part foundation before breath test results are admissible: (1) the device was in proper working order, (2) the operator was qualified, and (3) the test was properly administered. Failure to establish any part of this foundation is grounds for suppression. We file suppression motions whenever the evidence supports it — which is more often than prosecutors expect.

Call (801) 627-1110 to discuss the breath test in your case. Free consultation available 24/7.

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