What is "fire boss"

n. A person in charge of ascertaining the safety of a mine (gloss: excavation).

A fire boss is a person employed at a mine or state certified official, responsible for examining a mine for dangers, particularly explosive, poisonous or suffocating gases. Usually the fire boss is the first person to enter a mine, to verify its safety, before a shift crew enters. It may also loosely refer to a foreman or shift manager.