When should construction site personnel be familiarized with the operation of portable fire extinguishers and other fire protection equipment?

The correct approach is to familiarize construction site personnel with the operation of portable fire extinguishers and other fire protection equipment upon hiring. This is crucial because new employees must understand how to use these safety tools before they encounter a situation that requires their use. Immediate training ensures that all personnel are prepared from day one to act effectively in case of a fire emergency, promoting overall safety on the construction site.

While other options suggest regular or ad-hoc training, they do not emphasize the importance of training new hires right at the outset. Daily or monthly training might not be feasible or necessary once personnel are already trained, and "as needed" might lead to gaps in knowledge if an emergency arises when someone is not adequately prepared. Providing this training upon hiring ensures that all employees have the foundational knowledge required to respond quickly and safely to fire hazards from the start of their employment.