Historically, mining operations such as Singareni Collieries employed canaries to detect airborne hazards due to their acute sensitivity to air quality fluctuations. The primary gas identified by canaries in this context was carbon monoxide.
Canaries served as an early warning system for carbon monoxide poisoning, as they would succumb to the gas much faster than humans. This allowed miners to take necessary precautions, like evacuating or improving ventilation. Methane, ozone, and sulphur oxide were not historically detected by canaries in mines, thus establishing carbon monoxide as the appropriate gas for the scenario.