Which statement best describes a nox box?

A nox box is specifically designed as a secure storage solution for critical building access keys. This allows first responders and emergency personnel to quickly and efficiently gain access to a building during an emergency situation, enhancing safety and response times. The design of a nox box ensures that authorized individuals can retrieve necessary keys without delays, which is crucial in urgent scenarios where every second counts.

In contrast, other options do not accurately reflect the primary function of a nox box. A storage box for fire extinguishers, a display case for emergency instructions, or a containment unit for hazardous materials serve different purposes related to safety and emergency preparedness but do not pertain to building access. Understanding the unique role of a nox box is essential for effective emergency response planning and building management.