what is a permit required confined space

Safety regulations and procedures for permit-required confined spaces include several key components:

Entry Permits: All spaces are considered permit-required confined spaces until pre-entry procedures prove otherwise. A Confined Space Entry Permit must be completed before entry is allowed, verifying the completion of required items. A written copy of operating and rescue procedures must be available at the job site. If work is interrupted or alarm conditions change, a new permit must be completed. The permit specifies isolation methods and preparations needed before entry. [2] [3]

Hazard Control: Control of atmospheric and engulfment hazards is crucial. The surrounding area should be surveyed to identify hazards like drifting vapors. The confined space atmosphere must be tested for dangerous air contamination, oxygen deficiency, LFL, and hydrogen sulfide concentration using a direct reading gas monitor. Testing should be performed by a trained supervisor, and a written record of pre-entry test results must be kept at the job site and be available for review by affected employees. Mechanical ventilation systems should be set to 100% outside air, and additional manholes should be opened to increase air circulation where possible. Entry may not begin until testing demonstrates that the hazardous atmosphere has been eliminated. [2] [2] [2] [4]

Rescue Plans: Rescue procedures must be in place, including summoning rescue and emergency services and preventing unauthorized personnel from attempting a rescue. At least one worker should stand by outside the space ready to give assistance in case of emergency, equipped with a self-contained breathing apparatus. Continuous powered communications shall be maintained between the worker within the confined space and standby personnel. The standby worker may only enter the confined space in case of an emergency, wearing the self contained breathing apparatus, and only after being relieved by another worker. A safety belt or harness with attached lifeline shall be used by all workers entering the space, with the free end of the line secured outside the entry opening. [4] [4]

In any situation where their use may endanger the worker, use of a hoisting device or safety belt and attached lifeline may be discontinued. [4]

Continuous gas monitoring should be performed during all confined space operations. If alarm conditions change adversely, entry personnel should exit and a new permit should be issued. [4]

For sewer entry, potential hazards include engulfment, toxic gases (e.g., hydrogen sulfide >10 ppm), explosive flammable gases (>= 10% LFL), and oxygen deficiency (<= 19.5%). [5] [5] [5] [5]

Confined spaces may be entered without a permit or attendant if the space can be maintained in a safe condition by mechanical ventilation alone. A Confined Space Pre-Entry Check List must be completed before entry. [5]

Pumps and lines that could cause contaminants to flow into the space should be disconnected, blinded, and locked out, or effectively isolated by other means. [5]

The atmosphere within the space will be tested to determine whether dangerous air contamination and/or oxygen deficiency exists. The minimum parameters to be monitored are oxygen deficiency, LFL, and hydrogen sulfide concentration. A written record of the pre-entry test results shall be made and kept at the work site for the duration of the job. The supervisor will certify in writing, based upon the results of the pre-entry testing, that all hazards have been eliminated. Affected employees shall be able to review the testing results. [1]

Workers will immediately leave the permit space when any gas monitor alarm set points are reached. Workers will not return to the area until a supervisor has evaluated the situation and determined that it is safe to enter. [1]

Arrangements for rescue services are not required where there is no attendant. [1]

Each entry employer must implement measures to prevent unauthorized entry; identify and evaluate hazards of permit spaces before entry; and develop and implement the means, procedures, and practices necessary for safe permit space entry operations, including specifying acceptable entry conditions. [6] [6] [6] [6]