Oregon DUI Intoxilyzer 8000 Breath Testing

Oregon Intoxilyzer 8000

The Intoxilyzer 8000 is a breath testing device sometimes referred to as a “breathalyzer.” For several years, Oregon used the Intoxilyzer 5000. In the Fall of 2006, the Oregon State Police began installing new Intoxilyzer 8000 units around the state and the use of the Intoxilyzer 5000 was discontinued completely in Oregon. The theory behind both of these breath testing devices is that blood-alcohol levels can be estimated by testing the alcohol content of a person’s breath. However, there are problems with Intoxilyzer 8000 breath testing.

How does the Intoxilyzer 8000 work?

To provide a breath sample into the Intoxilyzer 8000, you must blow long and strong into the mouthpiece attached to the machine. You must then wait, and provide a second sample. The machine will only print a reading if you complete both portions of the test (two full blows). Another factor that can cause the machine to provide an inaccurate reading is the sample volume. The Intoxilyzer 8000 only requires 1.1 liters of breath to produce a reading, but many people provide samples larger than this. Scientists knowledgeable about breath testing will tell you that the longer you blow, the higher you go. This means that, when the arresting officer tells you to keep blowing longer and harder, he is not likely doing this to help you. Your attorney can request COBRA data from the Intoxilyzer 8000 so you can see for yourself that longer blow times and larger samples usually result in a higher breath alcohol estimate.

Intoxilyzer 8000 Accuracy and Margin of Error

There are many other reasons that Intoxilyzer 8000 breath testing should not be trusted. Speak with your attorney about the machine before you assume that a high reading means that you, or someone that you car about, was “drunk.” A breath test reading is an estimate only and can be effected by all of the following factors:

  • Breathing Pattern
  • Breath Temperature
  • Male vs. Female Test Subject
  • Ethnicity
  • Lung Capacity
  • Partition Ratio
  • Outdated Software
  • Source Code Errors
  • Individual Machine Variance/Variability
  • Problematic/Defective Machine
  • Inadequate Machine Maintenance
  • Inadequate Maintenance Records
  • Radio Frequency Interference (RFI)

What does an Intoxilyzer 8000 cost?

Both the Intoxilyzer 5000 and the Intoxilyzer 8000 are made in Kentucky by CMI, Inc. The old and outdated Intoxilyzer 5000 units are sometimes available on eBay for sale. However, it’s difficult to determine exactly what an Oregon Intoxilyzer 8000 costs because you can’t buy one. It’s easy-enough to determine what the Oregon State Police paid for their units, but they bought them in large quantities as part of a comprehensive contract. The average person cannot walk into a store and purchase an Intoxilyzer 8000, or order one online. The machines are not sold, leased, rented, or loaned to anyone other the law enforcement. This means defense attorneys cannot have access to them. CMI will not sell or lease its products to any independent scientific labs for testing and CMI will not disclose how the machine works by allowing the computer source code (used to program the machine and to tell the machine how to function) to be revealed or analyzed by independent scientists and computer programmers. Even the Oregon State Police Crime Lab personnel have admitted they do not have access to the source code of the machines and they cannot say exactly how the machines produce their results.

The new Intoxilyzer 8000 has many differences from the older Intoxilyzer 5000, but the principles upon which the device purports to gauge a driver’s blood alcohol content are very similar. The Intoxilyzer 8000 uses the principle of infrared light absorption to attempt to estimate the present of alcohol in a gas sample. In theory, the Intoxilyzer 8000 is supposed to be able to estimate blood alcohol level from breath alcohol level by extrapolating using a presumed ratio (often referred to as a partition ratio). Despite the fact that the partition ratio varies from person to person, the Intoxilyzer 8000 makes an assumption that the ratio is the same for everyone and that it’s 2,100:1. This means that the Intoxilyzer 8000 assumes that for every molecule of alcohol in your breath, that there are 2,100 molecules in your blood stream. If, because of body size, lung capacity, ethnicity, or other factors, your partition ratio is higher or lower than the Intoxilyzer 8000 assumes it is, your test result will vary wildly and could result in a false reading about the .08 standard.

The Intoxilyzer 8000 is also prone to errors due to mouth alcohol and interferants. While the Intoxilyzer 8000 is supposed to be able to distinguish other interferants (such as solvents or volatile organic compounds) from alcohol, it cannot if the molecules are similar in shape to those of alcohol. People who work around paints and solvents, for example, will often have false readings when they blow into an Intoxilyzer 8000. Similarly, the manufacturer of the Intoxilyzer 8000 states that the machine has a slope detector in order to detect mouth alcohol which might provide a false reading, but the slope detector does not work all the time. Mouth alcohol could be present for someone who was recently drinking or who burped, vomited, or regurgitated prior to providing a breath sample. To be clear, I have witnessed the slope detector function as designed and report mouth alcohol for someone who had not been drinking, but had swished mouthwash just before the test. However, I have personally witnessed on more than one machine, people who had been drinking (although who were not intoxicated and not over a .08, blow readings in the .20-.30 range and the machines had no idea the result was from pure mouth alcohol (the test participants had swished with either mouthwash or had alcohol to simulate recent drinking or belching).

Intoxilyzer 8000 Problems

When the Intoxilyzer 8000 has a problem and cannot function, it produces what are called “exception messages.” Problems with the machine that prevent it from completing a test include– but are not limited to:

  • Interfering Substance Detected: This exception can occur when a substance other than alcohol (i.e., acetone, toluene, other volatile organic compounds, sometimes referred to as VOCs) is detected in the breath sample.
  • Improper Sample: This exception can occur when a subject blows into the mouthpiece at an improper time during the testing sequence.
  • Check Ambient Conditions: This exception will occur when alcohol, or a contaminant, is being introduced into the sample chamber from the surrounding room air during the “Air Blank”.
  • Purge Fail: This exception occurs when the instrument is unable to purge the sample cell after running a breath test. This may be due to the purge pump not operating or the breath path being obstructed.
  • Subject Test Refused: This exception occurs when the operator terminates the testing sequence because the subject refused to continue.
  • No Sample Given: This exception can occur when the test subject does not blow hard enough into the instrument to activate the audible tone during the breath sampling period.
  • Residual Alcohol Present: This exception can occur when residual alcohol is detected in the subject’s mouth or upper respiratory tract. This could be the result of recent consumption of alcohol or having vomited or regurgitated liquid from the stomach into the mouth.
  • RFI Detected: This exception can occur when a radio or cellular phone transmission is detected near the instrument.
  • Unstable Signal: This exception can occur when the instrument can not obtain a stable reference during the testing sequence.
  • Subject Sample Correlation Failure: This exception can occur when the subject does not provide two similar valid breath samples. This could be a result of improper breath sample delivery or residual alcohol in the subject’s upper respiratory tract.
  • Sequence Aborted by Operator: This exception occurs when the operator aborts the testing sequence.
  • Range Exceeded: This exception occurs when the test result was higher than 0.60 %BAC. This could be due to a high concentration of residual alcohol in the subject’s mouth or upper respiratory tract from recent consumption of alcohol or having vomited or regurgitated liquid from the stomach into the mouth.
  • Control Out of Tolerance: This exception occurs when the result obtained by the instrument during the testing of the external ethanol breath standard is out of tolerance.
  • Diagnostic Failure: This exception occurs when the instrument fails the diagnostic routine.
  • Deficient Sample: This exception occurs when the subject does not blow long enough with sufficient force to properly provide a sample during the breath sample period.

Note: Just because your breath test did not result in an exception message does not mean that your breath test reading was accurate or without factual or legal error in the process. For more detailed information, please see our dedicated page on error messages and exception codes.

Should I trust the Intoxilyzer 8000?

Many people are skeptical of the accuracy of DUI breath testing, and therefore they are not sure whether to “blow” or “refuse.” The decision of whether or not to provide a breath sample is complicated. There are both administrative and quasi-criminal (i.e. violation) penalties for refusing to submit to the breath test. However, the Intoxilyzer 8000 is not always accurate and a false high reading can result in a greater possibility that you’ll be convicted of the crime of DUI. If you refuse, there is a very strong likelihood that the arresting officer will obtain a search warrant to take a blood sample from you for testing. For better or for worse, blood testing is more accurate than breath testing.

If you are reading this page, you are not likely sitting in the local jail or at a police station making the decision of whether or not to provide a breath sample. You probably either already provided a breath sample, or you refused. In any event, you should speak with an attorney about your options regarding your breath test or refusal. You should not assume that any breath test result over .08 means that you will be convicted of DUI or that you will lose your driving privileges. Similarly, you should not assume that the local District Attorney’s office will not charge you with DUI if you blew a .07 or even a .05.

For more information on the topic of breath test refusals, please see our page “Should I take the breathalyzer test?

Intoxilyzer 8000 Manual

For more specific information about the rules and procedures that govern proper use of the machine, you can read the Intoxilyzer 8000 Operator’s Guides:

Oregon Intoxilyzer 8000 Expert

If you’ve been arrested or cited for DUI in Oregon, contact our office. Oregon DUI Lawyer Michael Romano is not only an experienced and knowledgeable DUI lawyer, but he’s been trained in the administration of breath testing and use of the Intoxilyzer 8000.

Scroll to Top
Call Now Button