The confined space entry permit is a formal safety document that authorizes and controls entry into hazardous work areas. This permit process is a procedural safeguard required by regulatory bodies, such as the Occupational Safety and Health Administration (OSHA). The entry permit serves as a checklist and a record, confirming that all required safety measures have been implemented before entry begins. It formalizes the systematic evaluation of the space, ensuring all known and potential hazards are addressed and controlled.
What Defines a Permit Required Confined Space?
An entry permit becomes mandatory only when a space meets the criteria for a “permit-required confined space.” A general confined space is defined by three characteristics: it is large enough for a worker to enter and perform assigned work, it has a limited means of entry or exit, and it is not designed for continuous employee occupancy. Examples of these spaces include tanks, silos, pits, and vessels.
A confined space is elevated to the “permit-required” designation if it presents one or more serious safety or health hazards. These hazards include the potential to contain a hazardous atmosphere, such as insufficient oxygen or flammable gas concentrations. The space is also permit-required if it contains material that could engulf an entrant, or if its internal configuration could trap or asphyxiate a worker. The presence of any other recognized serious safety or health hazard, such as unguarded machinery or heat stress, also triggers the permit requirement.
The Critical Timing of Permit Completion
The permit must be fully completed, authorized, and posted at the entry point immediately before any worker enters the space. The entry supervisor must sign the permit to authorize entry only after all pre-entry preparations have been successfully completed and documented. This ensures that the conditions verified on the permit are current and accurate at the moment of entry.
Entry cannot commence based on a preliminary, unverified, or partially completed permit. The purpose of the permit is to confirm that acceptable entry conditions exist, and this verification must be immediate and concurrent with the final preparatory checks. Once the permit is signed and posted, it serves as a visible certification to all authorized entrants that the space has been prepared for safe work.
Essential Steps Before Permit Issuance
Before the entry supervisor can sign and issue the permit, a series of safety procedures must be performed and documented directly onto the permit form. Atmospheric testing is among the most important checks, requiring calibrated instruments to verify acceptable conditions. The air must be tested for oxygen content, flammability (combustible gases), and toxic substances like carbon monoxide and hydrogen sulfide, with the results and tester’s initials recorded.
Isolation of all energy sources is mandatory to prevent accidental activation of equipment within the space. This typically involves applying lockout/tagout procedures to mechanical, electrical, hydraulic, or pneumatic systems, and physically blanking process lines. The permit must also verify that ventilation has been set up, especially continuous forced-air ventilation, to maintain safe atmospheric conditions. Finally, the permit must confirm the availability of rescue and emergency services and detail the means for contacting them, often including verifying the response capability of an off-site rescue team.
Duration and Validity of the Entry Permit
The permit is only valid for a specific, authorized duration, which may not exceed the time required to complete the assigned task. While some permits are valid for a single shift, the duration is determined by the scope of the work and the conditions documented on the form. Continuous monitoring is required throughout the entry operation to ensure the conditions remain within the acceptable limits specified on the permit.
The permit becomes invalid and entry must be terminated if any unauthorized or prohibited condition arises in or near the permit space. This includes the detection of a hazardous atmosphere, the failure of a control measure, or if the entry supervisor leaves the area without a replacement. If the work is interrupted or conditions change, re-entry is prohibited until the space is re-evaluated, and a new permit may be required.
Closing and Documenting the Permit
Once the work is completed and all authorized entrants have exited the space, the entry supervisor must terminate the entry and cancel the permit. The termination process involves accounting for all personnel to ensure no one remains inside, and securing the space to prevent unauthorized entry. The entry supervisor must also note any problems encountered during the operation on the canceled permit.
The employer must retain the completed and canceled entry permit for a minimum of one year. This retention is a regulatory requirement to facilitate the review and auditing of the overall confined space program. Information from the retained permits, especially notes on encountered problems, is used to revise the program and improve safety procedures for future entries.