BrAC refers to your breath alcohol concentration. The BrAC detected by your IID must be under a limit set by your state (usually 0.02) before you’re allowed to start and operate your vehicle. Each state determines how many attempts you have at providing a passing sample. If you have questions about the legal limits in your state, you can contact an Intoxalock state specialist for help answering specific questions about state ignition interlock laws.