For flooded lead acid and other types of batteries, the ventilation system must limit hydrogen concentration to what percentage of the total volume of the room?

In environments where flooded lead-acid and other similar types of batteries are used, proper ventilation is critical to ensure safety. When these batteries are charged, they can produce hydrogen gas, which is highly flammable and poses an explosion risk if allowed to accumulate in the air. Therefore, the ventilation system must be designed to keep the concentration of hydrogen well below the lower explosive limit.

The correct percentage limit for hydrogen concentration is 1%. Keeping hydrogen concentration at or below this level minimizes the risk of combustion and maintains a safe environment for workers and equipment. This threshold aligns with safety protocols established for battery storage and charging facilities, ensuring that the risk of hydrogen buildup is effectively managed.

Other options, while they may seem reasonable, would allow for higher concentrations of hydrogen in the air, thereby increasing the risk of explosive conditions. Thus, maintaining a concentration of hydrogen at 1% or less is essential for safety when working with flooded lead acid batteries.