Whether caused by a natural hazard or some other event, power loss at hazardous chemical facilities can lead to a variety of negative impacts. Pumps and compressors may stop running, stirrers may quit mixing, lights may go out, and instruments and controls may malfunction. These equipment outages can lead to tank overflows, runaway chemical reactions, temperature or pressure excursions, or other process upsets which could lead to a spill, explosion, or fire. Even if there is no immediate release, thermal shock or other factors could result in a delayed effect that compromises the mechanical integrity of equipment during subsequent operations. When power is restored even after a brief interruption, some equipment may automatically restart before process operations are ready, while other equipment may need to be reset and manually restarted. When a facility relies on electrical power for any aspect of its process operations, it is imperative to anticipate how power loss affects the safeguards that prevent releases of hazardous chemicals.