What is the maximum allowable time for smoke to travel in the air?

The maximum allowable time for smoke to travel in the air is established based on safety standards to ensure that occupants can be alerted to danger and evacuate safely. In this context, 120 seconds is considered an acceptable duration for smoke travel under certain conditions, like the distance smoke needs to travel within a building before an alarm can be triggered or before evacuation is recommended. This time allows for an adequate response from a fire alarm system, ensuring that occupants are made aware of the situation and can take necessary actions, such as evacuating or seeking shelter.

This standard is rooted in various fire safety codes and guidelines aimed at minimizing risks associated with smoke inhalation, which can occur even before a fire becomes fully developed. Understanding this timeline helps in designing effective fire alarm systems and emergency response protocols that can be critical during a fire incident.