What must be done when a carbon dioxide extinguisher has lost 10% of its charge?

When a carbon dioxide extinguisher has lost 10% of its charge, it is crucial to recharge it to ensure it operates effectively in an emergency. Fire extinguishers rely on a certain pressure level to function correctly, and a loss of charge indicates that the extinguisher may not deliver the necessary suppressive agent when needed.

Recharging restores the extinguisher to its full operational capacity, ensuring all components, including the nozzle and the discharge valve, can perform their functions properly. Keeping extinguishers at or near full charge is essential for the safety of individuals in the vicinity, as it guarantees that the extinguisher will work as intended when faced with a fire situation.

The other choices involve actions that do not appropriately address the need for recharging when there is a detectable loss of charge. For example, simply replacing it with a new extinguisher or waiting until it is empty fails to proactively maintain fire safety measures. Additionally, sending it for maintenance might not be necessary if a straightforward recharging of the unit can resolve the issue. Thus, recharging is the correct step to take to maintain fire safety readiness.