Preliminary Breath Testing

During the pre-arrest investigation of a person for DUI, the arresting officer might ask the subject to submit to a preliminary breath test (often called the “PBT”).

The preliminary breath test is performed on a portable and handheld device. These devices are often called one of the following:

  • alcohol screening devices
  • preliminary breath screeners
  • preliminary breath testing devices
  • portable breath testers
  • passive alcohol sensors

In Florida, the preliminary breath test results are not usually admissible in the criminal trial. In fact, the PBT results are not even admissible during a hearing on whether the officer had probable cause for the arrest.

Instead, the use of the preliminary breath tests is limited to administrative hearings at the DHSMV to suspend, revoke, or disqualify driving privileges after a zero-tolerance law violation. For this reason, the PBT is admissible in administrative proceedings against drivers who are:

If a PBT was used, it must be shown that the device is listed on a current copy of the United States Department of Transportation’s conforming product list. Click here to find a list of preliminary alcohol screening test devices listed on the DOT conforming product list.

Non-criminal Infractions for Driving with a BAC of .02 while under 21

Florida Statute Section 327.355(3) provides:

A breath test to determine breath-alcohol level pursuant to this section [for having a BAC of .02 or higher] may be conducted as authorized- by… a preliminary alcohol screening test device listed in the United States Department of Transportation’s conforming-product list of evidential breath-measurement devices. The reading from such a device is admissible in evidence in any trial or hearing.

A violation of this section for being under 21 and driving with a BAC of .02 is a noncriminal infraction, and being detained pursuant to this section does not constitute an arrest.

In an administrative hearing for the driver under 21, the reading from the PBT is presumed accurate and is admissible in any administrative hearing conducted under the authority of Florida Statute 322.2616.

Reasons the PBT is Less Accurate or Reliable

The PBT is less accurate and reliable than the evidentiary breath test instrument used in Florida, the Intoxilyzer 8000. The main problem with the accuracy and reliability of the PBT is caused by the fact that the device is sensitive to temperature changes and environmental factors.

Other problems occur because of radio frequency interference (RFI) caused by radio equipment or cell phones. RFI can cause the device to register an inflated reading or even prevent the PBT device from producing any result.

Limited Purposes of the PBT Reading

The PBT provides an on-the-spot indication of the subject’s BAC, but it does not indicate the level of the subject’s impairment because impairment varies widely among individuals with the same BAC level.

In other states outside of Florida, the results of the PBT are admissible are used for certain limited purposes, including:

  • to determine the validity of the arrest;
  • to determine whether the BAC was lower or higher at the time of driving.

This article was last updated on Friday, January 5, 2023.