How do I take a breath alcohol test?

By John Hawes | Last updated: January 16, 2019

The individual testing procedures for a blood alcohol test will vary depending on the type of breath alcohol testing device used and the circumstances involved in your particular situation. However, all breath alcohol tests require an exhaled breath sample for analysis. In most instances, you will provide this sample by exhaling into a sterile straw or mouthpiece connected to the breath alcohol machine.

How to Provide a Breath Sample

Breath alcohol tests detect the volume of alcohol present in your exhaled breath and then use a formula to calculate a blood alcohol concentration or content (BAC) based on that value. When you take a breath alcohol test, you will be asked to exhale forcefully to provide what is called a "deep lung" or alveolar air sample. This deep lung air is needed to ensure that the sample accurately represents the volume of alcohol that has evaporated into your lungs from your blood.

Some breath alcohol machines have internal sensors designed to detect when a deep lung sample has been submitted. Other machines require you to exhale for a specified length of time. For instance, you may be asked to exhale for a minimum of 6 seconds. Still other devices are equipped with a bag or balloon that you must inflate to demonstrate that you have provided a sufficient sample. To produce a suitable sample, you should make sure that your mouth forms a complete seal around the mouthpiece when exhaling. In most instances, you will not be permitted to touch the mouthpiece, straw, or the tube connecting it to the breath alcohol testing device.

Legal Procedures and Observances

While a screening breath alcohol test may be performed as soon as requested, a breath alcohol test that may subsequently be used for evidentiary purposes requires adherence to formal evidentiary procedures. The specifics of these procedures, including chain of custody requirements and types of testing devices permitted, will vary depending on the law or regulation under which the testing is being performed.

For testing required by Department of Transportation (DOT) regulations, your alcohol test will be administered by a breath alcohol technician (BAT). The test will be conducted using an alcohol screening device approved for DOT testing; and the administrator will follow a series of steps to confirm that the breath alcohol machine is functioning properly before your test.

Upon arriving at the test collection site, you will be asked to present a photo ID card. The BAT will then ask you a series of questions that he or she will use to fill out a DOT Breath Alcohol Testing Form (ATF). You will be required to sign this ATF. If you refuse to sign the ATF, you will be deemed to have refused to take the breath alcohol test.

After the paperwork has been completed, you will provide a breath sample. Either an approved alcohol screening device (ASD) or an evidentiary breath alcohol machine (EBT) may be used for this initial test. Both you and the BAT will observe the results of your test. If the result indicates a blood alcohol concentration of less than .020, then you have passed the breath alcohol screening test. If the results indicate a BAC of .020 or higher, then a confirmation test will be conducted. This test may be performed by the same, or another, BAT.

Confirmation Testing

An evidentiary breath alcohol machine must be used for your confirmation test. This machine will also be evaluated to ensure that it is working properly. Even if you are tested using the same device as for your screening test, you will use a new mouthpiece for the confirmation test. You will also be asked to observe a 15-minute waiting period during which you may not to eat or drink, place any object or substance in your mouth, or belch (if possible). This wait is to ensure that your breath does not contain mouth alcohol but only evaporated alcohol from your lungs. Residual mouth alcohol from substances such as mouthwash, cough drops, or from recent alcohol consumption, may be present in the mucous lining of your mouth, in your esophagus, or even in your dental work. By observing a waiting period, you are protected from any chance that the breath alcohol machine might register a higher concentration of alcohol caused by mouth contaminants. Your confirmation test must be conducted within 30 minutes after the completion of the screening test. The results of the confirmation test will then be available for you to view.

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Workplace Testing 101 Alcohol Testing Oral Fluid Testing Health and Safety

Written by John Hawes

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John Hawes is the CCO and co-founder at SureHire Occupational Health Testing. John graduated in 2001 from the University of Alberta with a Bachelor of Science degree in physical therapy. As a former physical therapist, John uses his knowledge of physical therapy and interest in ergonomics and biomechanics to devise fit for work testing.

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