Special Considerations - Rules

If a confined space meets all of the criteria previously listed for non-permit required spaces, workers may enter the space under the following circumstances:

• Any conditions that make it unsafe to open the space must be eliminated before the cover of the confined space is removed (for instance, high pressure that might cause a blast of low-oxygen air to knock out the person who removes the cover).
• Once opened, the entrance must be guarded by some barrier that could stop people or objects from accidentally falling into the space.
• Before anyone can enter the space, the atmosphere must be tested for oxygen content, flammable gas, and potential toxicity. Anyone who enters the space must have access to this information.
• There should be no hazardous atmosphere in the space while anyone is inside.
• Continuous forced ventilation must be in place. This must completely remove atmospheric hazards before anyone enters, and must continue to pull air from a clean source throughout the entire time anyone is in the space.
• If possible, the air must be continuously monitored, and an alarm must go off if the air is found to be hazardous. If continuous monitoring is not possible, periodic monitoring can be used. Any entrant must be able to observe this testing to make sure he or she is safe.
• If a hazard is detected during entry, each entrant must leave the space immediately. The source of the hazard must be determined, and the hazard must be completely eliminated before anyone can enter again.
• There must be a safe way to enter and exit the space, and this is the employer's responsibility. If the employer uses a hoisting system, it must be approved for hoisting humans. The employer may make its own hoisting system on the job, but it must be approved by a certified engineer before use.
• All of the foregoing requirements must be proven through written, signed, and dated certification, and made available to all employees who might enter the space.

Many of these requirement are the responsibility of your employer, but it is important that you be aware of them as an entrant or attendant. Employers are required to make this information available to employees.

To learn more about Confined Spaces visit our Construction Confined Spaces Online Training web page.