Emergency means a situation or an occurrence of a serious nature, developing suddenly and unexpectedly, and demanding immediate action. This is generally of short duration, for example, an interruption of normal agency operations for a week or less. It may involve electrical failure or minor flooding caused by broken pipes.
36 CFR § 1223.2
See 1220.18 of this subchapter for definitions of terms used throughout Subchapter B, including part 1223.