wichita.edu
… asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section, or contains any other recognized serious safety or health hazard. Personal Protective Equipment (PPE): Equipment to protect eyes, face, head, and extremities, safety glasses, hard-hats, respirators, gloves, and protective clothing. Permissible…
https://www.wichita.edu/services/environmental_health_and_safety/Safety/confined_space_entry.php