What defines a confined space?

A confined space is specifically characterized as a space that has limited or restricted means for entry and exit, which directly aligns with the definition highlighted in the correct choice. Confined spaces can present significant safety hazards, especially when it comes to working conditions, as they are often not designed for continuous occupancy.

In practical terms, jobs performed in confined spaces may involve entering areas such as tanks, silos, sewers, or other similar environments where the access is constrained. This limited access can make it difficult to carry out rescues if an emergency arises, thus emphasizing the importance of understanding this definition in ensuring worker safety.

The other options do not encapsulate the essence of a confined space. For example, not all small areas necessarily fall under the definition of a confined space unless they also meet the entry and exit criteria. Additionally, a lack of ventilation and the presence of heavy machinery might create hazardous conditions but do not by themselves define a confined space, as many work areas can have these features without being classified in this way. A space that is large enough to work in does not meet the criteria for a confined space, as it implies sufficient area for safe movement and operation, contrary to the restrictive nature of confined spaces.