Under what circumstances should personnel wear personal protective equipment?

Personnel should wear personal protective equipment (PPE) in immediately dangerous to life and health (IDLH) atmospheres because these environments present extreme hazards that can quickly lead to serious injury or even death. IDLH situations often involve toxic gases, oxygen-deficient environments, or other serious hazards that can impair a firefighter's ability to function safely and effectively. Wearing appropriate PPE, which may include self-contained breathing apparatus (SCBA), protective clothing, gloves, and helmets, helps to shield firefighters from these dangers and allows them to perform their duties while minimizing risk.

In contrast, while training exercises do often require PPE for safety, they do not inherently pose the immediate life-threatening dangers found in IDLH scenarios. Non-emergency calls generally do not require the same level of protection as emergencies, and public events can vary in terms of risk depending on the situation. Hence, the necessity for PPE is most critical in IDLH situations where failure to protect oneself could result in fatal consequences.