Stop Work Authority (SWA) is a critical safety tool that empowers individuals to halt work when they observe unsafe conditions or behaviors. Here's what you need to know:

1. Authority and Responsibility: A safety watcher must have the authority to stop work if conditions become hazardous [1]. Any employee can exercise SWA if they believe that continuing the work would create an unacceptable risk.
2. Grounds for Stop Work: SWA should be used when there is an imminent danger, meaning a condition or practice that could immediately cause death or serious physical harm [2]. This includes situations where serious accidents are likely to occur immediately or before the hazard can be abated [2]. It can also be used if normal work procedures are inadequate to control a risk [1].
3. Procedure: To exercise SWA, the employee should immediately notify their supervisor or another responsible person. Work should cease until the hazard is assessed and controlled.
4. Safety Watchers: In certain situations, a safety watcher must be designated to observe work on or near energized electrical installations [1]. The safety watcher must warn of potential hazards, ensure compliance with safety requirements, be competent to evaluate hazards and initiate a rescue, and have the authority to stop work [1].
5. Non-Retaliation: Employees who exercise SWA in good faith must be protected from retaliation.
6. OSFM Stop Work Orders: The OSFM (likely referring to a specific state fire marshal's office) can issue stop work orders if someone is practicing without a required license or permit [3].

Remember, Stop Work Authority is a proactive measure to prevent incidents and ensure a safe working environment.