Which of the following describes a 'permit space'?

A 'permit space' is defined as a location that requires entry permits due to specific hazards that may be present. This definition emphasizes the need for established safety protocols, including the assessment of risks and implementation of safety measures to protect individuals entering the space. A permit system is intended to ensure that potential dangers—such as atmospheric hazards, physical hazards, or the need for specialized rescue plans—are adequately managed.

The other options do not encompass the full scope of what constitutes a permit space. While limited access and rigorous safety measures are important aspects of confined spaces, they do not inherently define a space that requires a permit. Ventilation might enhance safety, but it does not eliminate the risks that necessitate the permit system. Therefore, the correct answer highlights the requirement for entry permits, which serves as a proactive measure to manage and mitigate potential hazards in a confined space environment effectively.