What is a preliminary breath test?

A preliminary breath test (pbt) is a handheld breath alcohol testing device used by law enforcement in Vermont.

Preliminary breath tests are part of the battery of standard field sobriety tests (SFSTs) used for DUI detection in Vermont.

You are not required to submit to a preliminary breath under Vermont law, but police are not required to tell you that you can refuse it either.

If you do submit to a preliminary breath test (pbt) and your result is over .08 then Vermont police have probable cause to arrest you for DUI. This is true even if you performed perfectly and exhibited no clues on the other standard field sobriety tests.

Preliminary breath test results are not considered scientifically reliable evidence in Vermont courts, so the pbt is not admissible at a jury trial. It is allowed for the sole purpose of establishing probable cause for a DUI arrest in pre-trial proceedings.