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Confined Space Entry Program



Identification and Classification of Confined spaces Permit Required Confined Space Program - Program Components

Contractor PRCS entries





Confined space hazards are dangerous because often there are no apparent signs of danger, and rescuing a fellow employee who needs help is usually difficult. All existing hazards in confined spaces must be throughly evaluated before each entry into the space and monitored continuously thereafter. The work to be performed in the confined space shall be evaluated to assure that it will not pose an undue hazard during the entire duration of the work.


The purpose of this section is to define the confined space program at North Carolina State University. It contains the procedures that are needed to safely enter confined spaces and maintain regulatory compliance.


The requirements of this program apply to entries that are made by University employees into Permit Required Confined Spaces (PRCS). These requirements also apply to Departments which own confined spaces. There is also guidance on entries made by contractors or utility workers who are not University employees.

Definition of Key Terms

Confined Space - A space that:

  • Is large enough and so configured that an employee can bodily enter and perform assigned work;
  • Has limited or restricted means for entry or exit;
  • Is not designed for continuous employee occupancy.

In general, confined spaces are considered to be open topped enclosures with depths that restrict the natural movement of air; or enclosures with limited openings for entry and exit. Examples of confined spaces include: storage tanks, process vessels, bins, silos, boilers, ventilation or exhaust ducts, sewers, pipe chassis, underground utility vaults, tunnels, trenches, pits, and pipelines.

Permit Required Confined Space (PRCS) - A confined space that has at lest one of the following characteristics:

  • Contains or has the potential to contain a hazardous atmosphere;
  • Contains a material that has the potential for engulfing an entrant;
  • Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a smaller cross-section; or
  • Contains any other recognized serious safety or health hazard.

Alternate Procedure Confined Space - A confined space that has only a atmospheric hazard that can be controlled by continuous forced air ventilation.

Hazardous Atmosphere - An atmosphere that may expose employees to the risk of death, incapacitation, impairment of ability to self-rescue (escape without help from others), injury, or acute illness from one or more of the following causes:

  • Flammable gas, vapor, or mist in excess of 10% of its Lower Flammable Limit (LFL);
  • Airborne combustible dust at a concentration that meets or exceeds its LFL;
    Note: This concentration may be approximated as a condition in which the dust obscures vision at a distance of 5 feet or less.
  • Atmospheric oxygen concentration below 19.5% or above 23.5%;
  • Atmospheric concentration of any substance for which a dose or permissible exposure limit is published in Subpart G, Occupational Health and Environmental Control, or in Subpart Z, Toxic and Hazardous Substances, of the North Carolina Occupational Safety and Health Standards for General Industry, and which could result in employee exposure in excess of its dose or permissible exposure limit;
    Note: An atmospheric concentration of any substance that is not capable of causing death, incapacitation, impairment of ability to self-rescue, injury, or acute illness due to its health effects is not included.
  • Any other atmospheric condition that is Immediately Dangerous to Life or Health (IDLH).

IDLH - Immediately Dangerous to Life or Health means any condition that poses an immediate or delayed threat to life or that would cause irreversible adverse health effects or that would interfere with an individual's ability to escape unaided from a space.


Environmental Health and Safety Center

    1. Develop the University's written Permit Confined Space Program and update it when necessary.
    2. Provide guidance in the selection of air monitoring equipment and training in it's proper use.
    3. Help departments develop acceptable calibration and maintenance programs for air monitoring equipment.
    4. Assist in the development of entry procedures, selection and use of respiratory protection and personal protective equipment.
    5. Assist supervisors in identifying and classifying confined spaces.
Supervisors shall:
    1. Identify his/her personnel who will enter confined spaces.
    2. Provide detailed instructions and training on confined space hazards and entry procedures to those who may enter confined spaces.
    3. Identify and report work areas that have the potential to be confined spaces. A list of confined spaces shall be submitted to Safety Officer at EHSC, or 513-0988).
    4. Classify confined spaces as either "permit required" or "non-permit required".
    5. Inform employees who may enter the PRCS by posting danger signs or by training.
    6. Prevent unauthorized entry into spaces.
    7. Evaluate respiratory hazards and train personnel on routine measurement of respiratory hazards in confined spaces.
    8. Provide instruction to personnel on the proper use of equipment required for confined space entry.
    9. Maintain equipment that is used to enter confined spaces.
    10. Conduct annual work area audits to determine compliance with confined space entry procedures.
    11. Maintain records of equipment maintenance and employee training.
    12. Establish a Lockout/Tagout program.
    13. Conduct pre-entry briefing to inform entrants of the possible hazards that may be encountered in a confined space.
    14. Issue and cancel entry permits.
    15. Maintain canceled permits on file for one year.

University employees who enter confined spaces shall:

    1. Obtain the required training before entering a confined space.
    2. Follow the confined space entry procedures and any additional instructions given by their supervisor.
    3. Understand emergency procedures for confined space entry.
    4. Not enter a confined space that is suspected of having a hazardous atmosphere, even to rescue a fellow employee.
Contractors shall:
    1. Not allow their employees or subcontractors to enter a PRCS without having received confined space training and instruction in their individual duties.
    2. Have a written PRCS Entry Program and Permit system that is in compliance with OSHA regulations.
    3. Complete and sign the Contractor's PRCS Affirmation, (Appendix F), and return it to the Project Manager.
    4. Obtain any available information regarding permit space hazards or necessary entry procedures from the University Project Manager. (Construction Management, Facilities Operations, Telecommunications, Other)
    5. Coordinate entry operations with the University Project Manager when both University personnel and contractor personnel will be working in or near permit spaces.
    6. Inform the University Project Manager of any hazards confronted or created in permit spaces, either through a debriefing or during the entry operation.
    7. Upon request, provide a copy of the entry permit used for entry.
University Project Managers shall:
    1. Inform the contractor in writing that the workplace contains permit spaces and that entry is allowed only by following a PRCS Program that complies with OSHA regulations and NCSU entry requirements. Project drawings, specifications, and bid documents must identify PRCS.
    2. Notify the contractor of the hazards that have been identified and/or the experience that the University has had with the space.
    3. Not allow a contractor to enter a confined space until a signed copy of the Contractor's PRCS Affirmation, (Appendix F), has been received. (This should be received during the bid process.)
    4. Notify the contractor of any precautions or procedures that the University has in effect for employee protection in or near the space.
    5. Coordinate entry operations with the contractor when both University and contractor personnel will be working in or near permit spaces.
    6. Debrief the contractor at the conclusion of the entry operations regarding any hazards confronted or created in the space during entry.
    7. Report any confined spaces not on the list to Safety Officer at EHSC, ( or 513-0988).
Identification and Classification of Confined spaces

Each supervisor shall perform a workplace risk assessment to identify confined spaces, the hazards in or around the spaces, and the potential for hazards to develop in or around the spaces. The assessment shall identify all PRCS's as defined in section 1.4, along with all energy sources, moving equipment, and pipe inlets which must be controlled before entering the space.

Identifying Confined Space Hazards

Each supervisor shall evaluate the hazards of a confined space before allowing employees to enter. Identify any of the following:

Atmospheric Hazards


Physical Hazards

  • Asphyxiating
  • Flammable
  • Toxic
  • Moving machinery
  • Engulfment
  • Falls
  • Electrocution
  • Hazardous material
  • Noise
  • Burns
  • Heat stress
  • Any other hazard

Non-permit Confined Spaces

A Non-permit required confined space is a confined space that does not contain any physical or atmospheric hazards; nor is there a potential for these hazards to develop. Entry into confined spaces that do not require a permit should still be made with caution.

Persons desiring to enter a non-permit confined space shall:

    1. Enter the space only under the direction of their supervisor,
    2. Notify the supervisor in charge of the area where the space is located that an entry will take place,
    3. Determine if there has been any changes in the use or configuration of the space that will change it's classification,
    4. Determine if any activities in the area could cause a hazardous atmosphere to build up in the space,
    5. Not perform any activities in the space that could cause a buildup of a hazardous atmosphere, (i.e. welding, painting, or use of chemicals).
    6. Never work alone.
    7. Use continuous forced air ventilation for spaces that are below ground.

WARNING: Hazardous substances that are produced by activities in the general area of a confined space can migrate to, and accumulate in the space, creating an unseen hazard to an unsuspecting entrant.

The potential for a hazardous atmosphere to develop requires the space to be classified as a PRCS.

Alternate Procedure Confined Space

An alternate procedure confined space is a confined space in which the only hazard is an actual or potential hazardous atmosphere, and continuous forced air ventilation alone is sufficient to maintain safe entry conditions. The control of atmospheric hazards by forced air ventilation does not eliminate the hazards. The space, therefore, can not be considered a non-permit space. The atmosphere must be continuously monitored to verify that acceptable entry conditions are present. The entry permit is used to document that acceptable entry conditions can be maintained.

Persons desiring to enter an alternate procedure confined space shall:

    1. Review permit information and instructions.
    2. Test atmosphere.
    3. Ventilate space for a minimum of five (5) minutes. (See App. D)
    4. Re-test atmosphere to confirm that acceptable entry conditions are present.
    5. Enter space and check for hazards that may not have been detected.
    6. Monitor atmosphere throughout entry and record results every 30 minutes.
    7. Exit the space immediately if any of the following occurs:
      • A hazardous atmosphere is detected.
      • Any health or safety hazard is detected.
      • If entrants start to show signs of exposure to atmospheric hazards. (See App. B)
      (Reevaluate space and modify entry procedure before reentering.)
    1. When work is completed, return space to proper condition and secure opening.
    2. Return entry permit to supervisor.

For entries made into manholes or vaults that will last longer than 30 minutes, the entrant should wear a body harness with a line attached.

For further guidance review the following appendixes:


Permit Required Confined Space (PRCS)

A permit required confined space is a confined space in which there is a physical hazard or an atmospheric hazard that can not be controlled by continuous forced air ventilation alone. The Environmental Health & Safety Center should be contacted at 515-7915 or 513-0988 for assistance in evaluating hazards and developing an entry procedure that will protect the entrants.

Persons desiring to enter a PRCS shall:

  1. Review permit information and instructions.
  2. If possible, eliminate the physical hazards by:
    • Locking out - electrical sources at switches that are remote to the space.
    • Blanking & bleeding - pneumatic and hydraulic lines.
    • Disconnecting - mechanical linkages and belt or chain drives.
    • Securing - mechanically moving parts with chains, blocks, or other devices.
    • Plugging - pipe inlets

If all physical hazards can be eliminated, the space can be entered as either a Alternate Procedure or Non-permit space, depending on the condition of the atmosphere.

  1. Assign all entry team members a specific role to serve with detailed instructions.
  2. Determine method of communication between entrants and attendant.
  3. Test atmosphere.
  4. Ventilate space for a minimum of five (5) minutes. (See App. D)
  5. Retest atmosphere to confirm that acceptable entry conditions are present. Contact EHSC at 515-7915 or 513-0988 if continuous ventilation can not maintain acceptable entry conditions.
  6. Set up non-entry rescue equipment, (tripod and host).
  7. Put on body harness with line attached, (entrants only).
  8. Connect body harness to line from tripod.
  9. Enter space and check for hazards that may not have been detected.
  10. Monitor atmosphere throughout entry and record results every 30 minutes.
  11. Exit the space immediately if any of the following occurs:
    • A hazardous atmosphere is detected.
    • Any health or safety hazard is detected.
    • If entrants start to show signs of exposure to atmospheric hazards. (See App. B)
    (Reevaluate space and modify entry procedure before reentering.)
  12. When work is completed, return space to proper condition and secure opening.
  13. Note problems encountered on the permit.
  14. Return entry permit to your supervisor.

For further guidance review the following appendixes:

Permit Required Confined Space Program - Program Components

Preventing Unauthorized Entry

Supervisors shall prevent unauthorized entry into PRCS's by one or more of the following:

  • Locking entry point covers or requiring special tools to open
  • Training of employees
  • Posting warning signs
  • Providing information to contractors / visitors
  • Erecting barriers

All supervisors shall assure that all PRCS's in their area are accessible only by deliberate acts, or it is very clear that only authorized personnel are allowed to enter.

Safe Entry Procedures

Supervisors shall implement the procedures needed for a safe entry into a PRCS. The entry procedure shall include, but is not limited to:

  • The conditions that are acceptable for entry. (See App. G, Confined Space Atmospheric Testing)
  • How to isolate the permit space.
  • How to eliminate or control atmospheric hazards by purging, inerting, flushing or ventilating the permit space. (See App. D, Confined Space Ventilation)
  • The Lock-out/Tag-out requirements.
  • What personal protective equipment is needed.
    (See App. A, Confined Space Entry Equipment)
  • The means of communication between entrants and attendants.
  • Specific actions to be taken in case of an emergency.

The entry procedure shall be reviewed with all participants during the pre-entry briefing.

PRCS Equipment

Each department shall make available any equipment necessary for the safe entry into a PRCS; including, but not limited to:

  • Testing and monitoring equipment,
  • Ventilation equipment,
  • Communications equipment,
  • Personal Protective equiptment (PPE),
  • Lighting,
  • Barriers and shields,
  • Ladders,
  • Specialized tools,
  • Non-entry rescue and emergency equipment.

All equipment shall be maintained and supervisors shall ensure that employees use the equipment properly.
(See Appendix A, Basic Confined Space Entry Equipment )

Evaluation of Entry Conditions

Atmospheric testing is required to confirm acceptable entry conditions. Acceptable entry conditions shall meet the following basic requirements:

  1. Oxygen (O2) - greater than 19.5% and less than 23.5%,
  2. Lower Flammable Limit (LFL) - less than 10%,
  3. Carbon Monoxide (CO) - less than 35 ppm,
  4. Hydrogen Sulfide (H2S) - less than 10 ppm.

Note: The multi-gas monitor used should automatically alarm if any of the above values are exceeded.

If any other toxic or hazardous substance is present, or has the potential to be present, the proper monitoring equipment shall be obtained and operated by an individual who has been trained in it's use.

The PRCS shall be monitored to ensure that acceptable entry conditions are being maintained throughout the entry operation. If conditions deteriorate during entry, all entrants shall exit immediately and the space reevaluated.

If acceptable entry conditions cannot be maintained with continuous forced ventilation, contact the Environmental Health & Safety Center at 515 - 8658 or 513 -0988.

Appendix G, Confined Space Atmospheric Testing shall be followed and a copy shall be present at the job site during entry.

PRCS Attendants

An attendant shall be provided outside the PRCS to monitor the entrants for the duration of entry operations. The attendant shall be trained in confined space entries and instructed in his duties listed in Appendix H, Duties of PRCS Entry Team Members

Monitoring Multiple Spaces

It is not recommended that an attendant be responsible for monitoring more than one space at a time. However, it is allowed by the regulations if there is a way for the attendant to respond to an emergency in one or more of the spaces while still monitoring the other spaces. A radio, pull rope, whistle, horn, or some other means of communication must be set up for each space to notify the attendant of a problem. If an emergency, or any other situation arises that would require the full attention of the attendant, the attendant shall instruct the entrants of all spaces to exit immediately.

Designation of Roles

All employees participating in a PRCS entry shall be assigned one of the following specific roles to fulfill:

  • Entrant
  • Attendant
  • Entry Supervisor (May also be an entrant.)

The duties required for each role are listed in Appendix H, Duties of PRCS Entry Team Members.

Rescue and Emergency Services Procedure

Under no circumstances shall unauthorized personnel enter a confined space to attempt a rescue. At the present time there are no University employees authorized to perform confined space rescues.

The Raleigh Fire Department (RFD) has the Hazardous Materials and Technical Rescue teams that are needed for a confined space rescue. Wake County Emergency Medical Services (EMS) is responsible for providing emergency medical treatment.

In case of an emergency, contact NCSU Campus Police by one of the following methods:

  • Radio - declare an emergency and instruct the Service Center, (or anyone near a phone), to call - (911)
  • Campus Phone - (911)
  • Cell phone - (911)

University employees shall facilitate non-entry rescue by using retrieval systems and methods whenever entry into a PRCS is required, unless the retrieval equipment would increase the overall risk of the entry or would not contribute to the rescue of the entrant.

A retrieval system should consist of a chest or full body harness with a retrieval line attached at the center of the entrant's back near shoulder level, or above the entrant's head. The other end of the retrieval line shall be attached to a mechanical device or fixed point outside the permit space in such a manner that rescue can begin as soon as the attendant becomes aware that a rescue is necessary. For vertical spaces that are more than five (5) feet deep, a mechanical device, (tripod with a hoist), shall be available to retrieve personnel. In spaces where the entrant is not able to have a revival line attached, a full body harness should still be worn.

If an entrant is exposed to a substance that is required to have a Material Safety Data Sheet (MSDS), that information shall be given to the EMS personnel treating the entrant.

Written Permit System

Each supervisor shall document the completion of preparation needed for a safe permit space entry by preparing an entry permit, (App. E). The permit shall include the following:

  • acceptable entry conditions;
  • procedures needed to isolate the permit space;
  • steps necessary to control atmospheric hazards;
  • barriers needed to protect entrants from external hazards; and
  • steps necessary to ensure acceptable enter conditions are present through out the entry;

The entry supervisor shall sign the permit to authorize entry. The completed permit shall be reviewed with all authorized entrants and posted at the site of entry. The duration of the permit shall not exceed the time required to complete the assigned task. The entry supervisor shall terminate the entry and cancel the permit when:

  • the task listed on the permit has been completed; or
  • a condition that is not allowed under the permit arises in or near the space.

Each canceled entry permit shall be kept on file for 1 year to facilitate the annual PRCS program review. Comments concerning problems with entry operations should be noted on the permit so that entry procedures can be evaluated and revised if necessary.

Coordinating Entry Operations

When employees of more than one employer are working in or near the same PRCS, entry operations shall be coordinated through the University's Project Manager so employees of one employer do not endanger the employees of another employer.

Contractors are responsible for having their own PRCS program for their employees and shall be informed of any University specific safety information, such as how to contact NCSU Campus Police. A copy of the contractor's PRCS program shall be kept on file by the University's project manager.

All contractors shall be informed of any known hazards and/or past experiences that University employees may have had with the PRCS that is to be entered. At the conclusion of a contractor's entry operations, the University's Project Manager shall debrief the contractor regarding the entry procedures that were used and if the contractor encountered any hazards that were not known or if any hazards were created during entry.

Concluding Entry Operations

Once the entry is completed, verify that all entrants have left the space and that all equipment and supplies are accounted for. Check any gaskets or seals for damage and secure all openings. Use the PRCS Entry Permit to identify any locked-out/tagged-out or isolated equipment and return it to it's normal operating condition. Clean and inspect all entry equipment. Any items that were damaged during entry should be removed from service and repaired or replaced. Return equipment to it's proper storage place.

Make notes on the PRCS Entry Permit concerning any problems encountered during entry, or suggestions that would improve the PRCS Entry Program. Close and properly file the entry permit. Completed permits must be kept for one year and used to evaluate the PRCS Entry Program.

Review of Entry Operations

Supervisors shall review entry operations when there is reason to believe that the measures taken are not sufficient to protect employees. Examples of circumstances requiring the review of entry operations include:

  • an unauthorized entry into a PRCS,
  • the detection of a hazard not covered by the permit,
  • the detection of a condition that is prohibited by the permit,
  • the occurrence of an injury or near-miss during entry,
  • a change in the use or configuration of a space,
  • employee complaints about the effectiveness of the program.

Environmental Health & Safety should be contacted to assist with the review.

Annual Program Audit

The PRCS Program shall be reviewed annually by examining the canceled permits to ensure that employees participating in entry operations are protected from permit space hazards. Alternate entry certifications should also be reviewed.

Contractor PRCS entries

If an outside contractor is hired to work in a PRCS, it is the University's responsibility as a host employer to ensure that the contractor has a written PRCS program, uses an entry permit, and uses only workers that have been trained in PRCS operations. As a means to determine this, the contractor shall complete

Appendix F, Contractor's PRCS Program Affirmation, and return it to the project manager.

The project manager shall ensure that the contractor is:

  • informed in writing of the hazards that have been identified in/or near the space,
  • informed of any past experiences that University employees may have had in the space,
  • informed of any University safety procedures that are in place for the space,
  • debriefed afterwards as to the PRCS program followed and any hazards that were encountered or created in the space during entry.


Before participating as a member of an entry team, each employee shall be given confined space training as well as instruction in the specific duties to be conducted. The duties required for each role are listed in Appendix H, Duties of PRCS Entry Team Members. The training must provide employees with the necessary knowledge and skills needed to perform their duties safely.

Refresher training shall be given:

  • Every 24 months,
  • When the employee's duties change,
  • When space hazards change, or
  • When inadequacies in entry operations have been identified.

Hands on training in the proper use and care of tools and equipment is an essential part of the PRCS training program. This includes:

  • Appropriate personal protective equipment (PPE),
  • Air monitoring instrumentation,
  • Ventilating equipment,
  • Fire protection equipment,
  • Intrinsically safe electrical equipment, and
  • Retrieval and non-entry rescue equipment.

Training that has been successfully completed shall be documented by listing the names of the employees, the trainer, and the dates of training. This training certification shall be kept on file and available for inspection.

Confined space awareness training should be attended by supervisors who have employees that enter spaces, supervisors that have confined spaces in their work areas, and anyone who hires contractor's that will be entering NCSU spaces. Confined space awareness training should also be included in new employee training.