Minimum Breath Volume Requirement

Highly Knowledgeable Driving While Intoxicated Attorneys

The Alcotest is a breath test device that operates in accordance with set programming criteria that must be satisfied in order for a breath sample to yield a BAC reading. The primary issue in this regard involves the size of the breath sample and the duration of the blow needed to register a reading on the machine; this is commonly referred to as breath volume. The software that runs the Alcotest, referred to as firmware, requires: (1) a minimum air volume of 1.5 liters; and (2) a sustained minimum air volume of 4.5 seconds. In accordance with the findings in State v. Chun, it is acknowledged, however, that women over the age of sixty can have difficulty in achieving this level of minimum breath/air volume for the breathalyzer to register a BAC.

Why Does The Machine Require A Minimum Volume?

It is a generally recognized principle that an individual’s exhaling involves varying levels of alcohol concentration. Breath that comes from deep within the lungs will have a different concentration of alcohol (i.e. BAC) than breath that comes from the upper respiratory processes and/or mouth. By requiring a volume of 1.5 liters that covers a duration of 4.5 seconds, the firmware insures that the sample is more representative of the overall blood alcohol concentration in a person’s system. It was concluded that a sample containing less volume and/or of a shorter blow duration, would not achieve the goal of a fair sample.

What Happens If There Is Inadequate Air Volume?

If a sample fails to register 1.5 liters of volume or falls short of 4.5 seconds of sustained volume, the breath sample will be unacceptable. When this occurs, the Alcotest issues an error message “minimum volume not achieved.” The machine then gives the operator the option of recording the sample as terminated or to document the situation as a refusal. Whenever a blow is terminated, the machine permits another sample to be provided, up to eleven (11) samples, in total, for an individual subject. If the officer records the test as a refusal, it is supposed to be because the subject failed to make a good faith effort to provide the sample. A citation/summons for refusing to provide a breath sample under N.J.S.A. 39:4-50.4a usually follows.

Women Over Sixty (60) Years of Age

There is considerable data that supports the fact that women can have difficulty achieving 1.5 liters of air volume after they reach sixty (60) years of age. The same information indicates that the ability of a women to reach this level becomes even more difficult as they get older.

If you have any questions regarding breathalyzer readings, procedures followed by police in obtaining a breath sample, or any other issue involved in a DWI, an attorney from our office is ready to assist you.