scope:

Preparatory work usually involves conventional storage tanks, spheres, process vessels, and other equipment that might need to be entered. In principle, however, it also applies to furnace fireboxes, ducts, flues, large sewers, electrical vaults, deep sumps, pits, excavations, or any enclosed or confined area from which ready escape of workers may be difficult or in which flammable, inert, or toxic materials may be present.

Factors that usually should be considered are:

1. Condition of the atmosphere for safe breathing.

2. Prevention of fires or explosions.

3. Provision for ready entry and exit.

4. A voidance of contact with toxic and hot or cold substances that would be harmful to personnel.

5. Assurance of safe supports and footing .for personnel and protection from falling material.

6. Assurance of safe working temperatures.

7. Awareness of electrical, radiological, oxygen content, or other special fire and safety problems.