Which of the following is NOT a condition that requires SCBA to be used?

An oxygen-rich atmosphere does not necessitate the use of Self-Contained Breathing Apparatus (SCBA). SCBA is designed primarily for environments where air quality is compromised, such as when there are hazardous gases or insufficient oxygen levels. In contrast, an oxygen-rich atmosphere is generally considered safe for breathing, as it contains a higher level of oxygen than normal air, which is not problematic for respiratory health.

On the other hand, the other conditions listed—hazardous atmospheres, those that may quickly become hazardous, and situations involving ventilation near an active fire—all present potential threats that justify the use of SCBA for protection against inhalation of toxic smoke, gases, or other harmful particles. Understanding these distinctions is essential for ensuring personnel safety in environments that may pose breathing hazards.