Exhibit 4, 242 FW 11
General Safety Rules for Working in or Around Permit-Required Confined Spaces

Supersedes 242 FW 11, FWM 273, 09/30/96

Date: November 13, 2007

Series: Occupational Safety and Health

Part 242: Industrial Hygiene

Originating Office: Division of Safety and Health



PDF Version


1. You may only enter a permit-required confined space or be an entry attendant if you are authorized by the entry supervisor and you have completed the required confined space training.


2. There is no smoking in a confined space or near the entrance/exit area.


3. An entry attendant must be present at all times during entry.


4. Continuous visual or voice communication must be maintained between the entry attendant and the entrant(s).


5. You must not enter from the bottom or side, or work below the level of any hanging material or material which could cause engulfment.


6. The entry supervisor must monitor air and oxygen before you may enter any permit-required confined space.


                 Oxygen levels in a confined space must be between 19.5 and 23.5 percent. Levels above or below that will require you to use a self-contained breathing apparatus or other approved air supplied respirator.


                 Additional ventilation and oxygen level monitoring is required when you are welding. We will monitor levels of oxygen, explosive gas, and carbon monoxide.


                 You must not enter if explosive gas is detected above one-half the Lower Explosive Limit (LEL).


                 See 242 FW 11.10 for calibration requirements.


7. You must barricade confined space openings whenever you remove their covers.


For information on the content of this chapter, contact the Division of Safety and Health. For information about this Website, contact Krista Bibb in the Division of Policy and Directives Management.  

Visit the Division of PDM Directives Home Page
Visit the U.S. Fish and Wildlife Service Home Page