What requirement must be met for all gates in fenced enclosures?

For gates in fenced enclosures, the requirement for them to be locked when not in use is crucial for maintaining security and safety. This measure ensures that unauthorized access to the enclosure is prevented, which is particularly important in areas that contain hazardous materials or where safety protocols must be strictly followed.

Locking gates helps to control who can enter or exit the enclosure, thus minimizing the risk of accidents and ensuring that only qualified personnel have access. This practice is intended to protect both individuals and the surrounding environment by reducing the potential for exposure to dangerous situations.

In contrast, while automated gates, operational constraints from within the enclosure, and materials used for gates can also be important for certain contexts, they do not address the fundamental need for security and access control in the same way that locking gates does. Therefore, the emphasis on locking gates solidifies their role as a vital safety and security feature in fenced enclosures.