In DUI investigations, should a portable breath test be used as a substitute for a chemical test?

• A. No; it is a quick screen, not a substitute for a chemical test
• B. Yes; it replaces chemical testing
• C. It is used only if a chemical test is unavailable
• D. It provides the exact blood alcohol concentration

Answer: (A)

Portable breath tests are quick field screening tools used to detect the presence of alcohol and provide an approximate BAC, but they are not as accurate or reliable as a formal chemical test. Because chemical tests (evidentiary breath or blood tests) must meet strict calibration, technique, and reliability standards, they are the only method used to obtain legally defensible BAC evidence. Therefore, a PBT should not be used as a substitute for a chemical test. It can help indicate impairment or aid in deciding whether a chemical test is warranted, but the final, admissible BAC result comes from the chemical test, not the portable device.