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Office of Risk Management

Environmental Health & Safety

Confined Space Entry

These are the requirements to identify permit-required confined spaces (PRCS) in the workplace, inform workers about the spaces, revaluate non-permit confined spaces when there are changes in their use or configuration, and cooperate with contractors who will enter the permit spaces.

This Program provides procedures and guidelines for the safe entry and completion of work in confined spaces. Work in confined spaces can be performed safely provided that adequate safeguards and precautions are followed. Without such safeguards, personal injury or property damage may result from ignition of flammable gas or vapors, oxygen deficiency or enrichment, toxic, irritant, or other hazardous substances and/or physical hazards.

View the detailed program EHS S-004 Confined Space Entry

Responsibilities of Southern Methodist University

Note! Steps 3 through 12 may be the responsibility of a contracted entry team.

  1. To secure permit spaces to prevent unauthorized entry. 
  2. To evaluate and identify hazards before entry. 
  3. To implement operation procedures that ensure safe entry. 
  4. To provide and maintain the necessary equipment. 
  5. To evaluate PRCS conditions. 
  6. To provide attendant(s). 
  7. To develop and implement the specific methods to be used if attendants are responsible for monitoring more than one PRCS at the same time, or if an emergency occurs. 
  8. To designate the roles and responsibilities of all active PRCS entry team personnel. 
  9. To develop and implement effective rescue and emergency procedures. 
  10. To develop and implement an entry permit system. 
  11. To develop and implement procedures to coordinate entry operations when employees of more than one employer will enter a PRCS. 
  12. To develop and implement procedures for concluding an entry. 
  13. To periodically review entry operations. 
  14. To periodically review the permit space system.

Whom does the program apply?

SMU’s Confined Space Entry Program will apply any employee or contractor who will be entering a Confined Space. 

When any part of the body of an entrant breaks the plane of the opening of a PRCS large enough to allow full entry, entry is considered to have occurred and a permit is required, regardless of whether there is an intent to fully enter the space.

Program applies to all SMU faculty, staff and service providers who work under contract for SMU at all facilities owned and/or operated by SMU.  This Program applies to all field operations and associated facilities in which SMU has significant control over operations, as well as all designated confined spaces on SMU property.

What is a Confined Space?

OSHA defines a confined space as meeting the following criteria:

  • Is large enough for an employee to bodily enter and work
  • Has limited or restricted means of entry and exit
    • Cannot freely step into and out of the space without having to step over a raised threshold or stoop under the door opening
      • Ladders, stairs that are moveable, spiral, articulated (only fixed industrial works)
    • Equipment in the space or the travelling distance to the exit interferes with the entrants ability to escape in an emergency
  • Is not designed for continuous occupancy.

Evaluate the workplace to determine if any spaces are permit-required confined spaces.

If you determine that a space does meet the definition of “confined space,” then you need to further evaluate the space to determine whether it meets the definition of “permit-required confined space.”

What is a Permit Required Confined Space?

A permit-required confined space is a confined space that has one or more of the following characteristics:

  • Contains or has a potential to contain a hazardous atmosphere
  • Contains a material that has the potential for engulfing an entrant
  • Has an internal configuration that could trap or asphyxiate an entrant by inwardly converging walls or a floor which slopes downward and tapers to a small cross section
  • Contains any other recognized serious safety or health hazard

SMU will address whatever hazards are present by complying with other applicable standards and the general duty clause. (Under Section 5(a)(1) of the OSH Act of 1970).

A sign reading ‘DANGER - PERMIT-REQUIRED CONFINED SPACE, DO NOT ENTER’ will appear near many, but not all Confined Spaces. Always refer to SMU EHS Form SF-004-4 Confined Space Inventory for a listing of known Confined Spaces on campus.

SMU does not require the posting of signage of any permit space whose only means of access necessitates the use of tools or keys, provided that the employees (if any) who are expected to gain entry into these spaces are trained and if effective measures to prevent employees from entering permit spaces continuously takes place.

Alternate Entry Procedures

When entries are undertaken by means of the Alternate Entry Procedures, there are no SMU requirements for a rescue provisions however SMU still requires that a confined space entry permit be used and work authorized through the permit to work system.

Solo entries are permitted. In cases where the only hazards are exclusively atmospheric in nature and where continuous forced air ventilation alone is sufficient to maintain the permit space safe for entry, entry may be by means of the "Alternate Entry Procedures". The alternate entry procedures require that before employees enter, the internal atmosphere must be tested for:

  1. Oxygen content,
  2. Flammable gases and vapors, and
  3. Potential toxic air contaminants.

Once testing has been completed, the atmosphere within the space must be periodically tested to ensure the atmosphere remains safe for the entrants. There must be no hazardous atmosphere within the space when an employee is inside the space. If a hazardous atmosphere is detected during entry, employees must exit immediately, the space must be evaluated, and corrective measures must be taken.

The emphasis is squarely on use of continuous ventilation and atmospheric monitoring to ensure atmospheric hazards are controlled and that the atmosphere remains safe for entry. Because of the reliance on atmospheric monitoring to verify that conditions remain safe, OSHA has established a guideline of 50 percent of the level of flammable or toxic substances that would normally constitute a "hazardous atmosphere" as a safe level for entry using the Alternate Entry Procedures. As an example, a concentration of 5 percent lower flammability limit (LFL) combustible gas, or half the permissible exposure limit (PEL) concentration of a toxic gas, would represent a hazardous atmosphere per the Alternate Entry guidelines.

Reclassification of Confined Spaces

A non-permit confined space does not need to be revaluated annually if there are if there are no changes in the use or configuration of the confined space.

If there are changes in conditions that might increase the hazards to entrants, the Entry Supervisor and the EHS Department shall revaluate that space and, if necessary, permanently reclassify it as a PRCS.

If there are changes that downgrade a classification from Permit Required to Non-Permit Required, then that reclassification would remain in effect as long as the hazards remain eliminated. This reclassification would allow SMU or Contractors to have employees enter the space without implementing a full permit space program.

The elimination of the hazards can be accomplished by emptying the space of materials that pose an engulfment hazard and applying lockout/tagout to meet SMU EHS Program S-001 Control of Hazardous Energy. However, other provisions must be in place if a leak in a pipe opening in the space could lead to a hazardous atmosphere.

The Entry Supervisor shall document the basis for determining that all hazards in a permit space have been eliminated, through a written notice that contains the date, the location of the space, the atmospheric testing results, and the signature of the person making the determination. The certification shall be made available to each employee/contractor entering the space or to that employee/contractor's authorized representative and the EHS Department of the SMU ORM.  The EHS Department will review the information and make a determination of reclassification. All other applicable regulations shall be followed during work in the non-permit confined space.

Determine if the space may be temporality declassified as non-permit required confined space and that no hazardous work will be performed in the space; using form EHS SF-004-7.  If Confined Space may be temporarily declassified, a permit is not needed to begin work: 1) keep a signed copy at worksite 2) provided signed copy to Office of Risk Management prior to work proceeding.

If these criteria are met, rescue teams, special PPE, etc., are not required.

It is important to note that the difference between an alternative entry procedure and a non permit-required confined space is the use of forced-air ventilation. If forced-air ventilation is used during an entry, it cannot be classified as a non permit-required confined space. It must be classified as a permit required confined space using alternative entry procedures.

If hazards arise within a space that has been declassified to a non-permit space, each Entrant shall exit the space. The Entry Supervisor shall then re-evaluate the space, contact the SMU EHS Department, and determine whether it must be reclassified as a permit space.

Why is a Permit To Work Required?

As part of SMU’s Permit To Work Program, entry into a Permit Required Confined Space requires significant hazard controls to ensure all occupants will remain safe during work.

SMU will evaluate the hazardous conditions of the permit space, and when testing for atmospheric hazards, test first for oxygen, then for combustible gases and vapors, and then for toxic gases and vapors.

The type of testing that needs to be performed is dependent on the hazards that are present within the space. For permit spaces posing atmospheric hazards, atmospheric testing would be necessary. For other hazards, different tests will be necessary. For example, if the permit space poses thermal hazards, the temperature within the space would need to be tested. SMU requires whatever tests are necessary to ensure that acceptable entry conditions are present.

How do I receive a Permit to Work in a Confined Space?

A Confined Space Entry Permit may be retrieved at from the Office of Risk Management EHS Group or online here EHS Form SF-004-1

The Permit(s) application is submitted by the performing authority (PA) to the issuing authority/area authority (IA/AA) or permit to work authority (PTWA) for approval by end of business 5 days preceding the expected work day.

The Entry Supervisor is responsible for preparing the permit space for subsequent entry. Entry will not commence until all conditions listed on the entry permit are met.

Duration of Permit

The Confined Space Permits are 12 hour permits that are approved the day of the work being performed and closed at the completion of work with comments related to the day’s progress. A 12 hour extension may be granted by the IA and AA.  No more than two-12 hour shifts may be worked under the same work permit.

Confined Space Entry Team

At a minimum a 3 person team with rescue training and retrieval equipment is required for entry into a Permit Required Confined Space.

The positions can be rotating. An entry supervisor also may serve as an attendant or as an authorized entrant, as long as that person is trained and equipped as required by this section for each role he or she fills. Also, the duties of entry supervisor may be passed from one individual to another during the course of an entry operation.

To facilitate non-entry rescue, retrieval systems or methods shall be used whenever an authorized entrant enters a permit space, unless the retrieval equipment would increase the overall risk of entry or would not contribute to the rescue of the entrant.





Keep unauthorized entrants away from the space.




Remove unauthorized individuals who enter or who attempt to enter the permit space.




Communicate with entrants, monitor their status, and tell them when to evacuate.




Inform the entrants and the entry supervisor if unauthorized persons enter the permit space.




Communicate with the attendant regularly.




Remain outside the space during entry operations until relieved by another attendant.




Know the number and identity of authorized entrants.




Use all equipment properly.




Determine that acceptable entry conditions are maintained.




Exit from the permit space immediately given an order to evacuate, an alarm warning, or a sign of hazardous condition.




Know permit space hazards, including the mode, symptoms, and consequences of exposure.




Notify the attendant of any signs or symptoms of exposure to a hazardous condition.




Terminate the entry and cancel the permit when entry operations are finished or if a prohibited condition arises.




Verify entry conditions are acceptable before signing the permit and allowing entry.




Perform non-entry rescues if necessary.




Verify rescue services are available and the means for summoning them are effective.




Summon emergency responders when entrants need their services.




Atmospheric Hazards

Atmospheric hazards may include gases, vapors, dusts, oxygen-enriched or deficient atmosphere and/or poisons. Welding fumes, liquid residues in storage tanks, chemical products may produce atmospheric hazards.

  • Oxygen Level in Confined Space
    • Oxygen level should normally be 20.9%.
    • However, the level can change between 19.5% to 21.5%.
    • If the oxygen levels fall below 19.5% and rise above 21.5%, entry into the confined space would not be permissible. 

  • Hydrogen Sulfide (H2S) Level in Confined Space
    • H2S level may vary from 0 ppm to 10 ppm.
    • If the level rise above 10 ppm, confined space entry is not permissible.

  • Carbon Monoxide (CO) Level in Confined Space
    • Carbon monoxide level may vary between 0 ppm to 25 ppm.
    • If the level of carbon monoxide raises above 25 ppm, confined space is not permissible.

  •  % Lower Explosive Limit in Confined Space
    • It can be abbreviated as %LEL (Methane).
    • The safe level for hot work in the confined space is 0%.
    • %LEL (Methane) level can vary from 0% to 2%.
    • If %LEL (Methane) is above 2%, confined space entry would not be permissible. 

    Atmospheric Hazards Testing

    • It is required for ALL confined space work. 
    • It is done to identify any potential atmospheric hazards during any confined space work.
    • Atmospheric testing must be completed during the evaluation test, verification test and confined space continuous testing.

    Atmospheric Hazard Testing Procedures

    • There are two atmospheric hazard monitors:  QRAE 3 and MSA Altair 4X. 
    • The monitors are calibrated monthly by EHS.  A calibration sticker is placed on instrument.
    • Prior to each use, a fresh air calibration is required.  It must be performed in a known fresh air condition like outside.
    • During the descent into a layering atmosphere, atmospheric hazards should be tested about every 4 feet (1.22m) in the direction of vertical travel and to each side.
    • The longer the cord, the more time the instrument would need for the sample to reach the sensors.
      • For a 6ft 8 in cord, measurement should be taken for a minimum of 75 secs.
      • For a 10ft cord, measurement should be taken for a minimum of 80 secs.
      • For a 15ft cord, measurement should be taken for a minimum of 90 secs.
      • For a 25ft cord, measurement should be taken for a minimum of 110 secs or 1 min 50 secs.
    • If for any reason the entrant must leave the confined space, atmospheric testing must be completed before re-entry.
    • Test results must be recorded on the Confined Space Entry Form .

    QRAE 3 Instruction 

    1. Push and hold the power button until you hear a beep.
      • It will take about a minute to warm-up.
    2. Wait until the following message appears “Fresh Air / Zero Calibration.”  Select “Start”.
    3. A message will appear “Calibrating” and a timer.  The calibration will take about 30 seconds.
    4. Once the calibration is complete, the zero calibration results will be shown as indicated in the picture.
      • If you receive fail on any of the gas, perform the fresh air calibration again.  If the fail message appears again, contact EHS.
    5. Select “Exit”.
    6. It should return to the main screen.
    7. You are now ready to collect data.
      • Each measurement should be performed for a minimum of 60 seconds.
      • For a 6ft 8 in cord, measurement should be taken for a minimum of 75 secs.
      • For a 10ft cord, measurement should be taken for a minimum of 80 secs.
      • For a 15ft cord, measurement should be taken for a minimum of 90 secs.
      • For a 25ft cord, measurement should be taken for a minimum of 110 secs
    8. Record the data on the required form.

    MSA Altair 4X Instruction

    1. Push the Power button.  It will take a while to warm-up.
    2. A message “FAS?” would appear.  Push the Power button to select.
      • “FAS?” = Fresh Air Calibration.
    3. After the calibration, a message would appear “FAS PASS” or “FAS ERR”.
      • If you see “FAS ERR”, perform the fresh air calibration again. If the fail message appears again, contact EHS.
      • If you see “FAS Pass”, you are ready to proceed.
    4. After a couple of seconds, the main screen should appear.
    5. You are now ready to collect data.
      • Each measurement should be performed for a minimum of 60 seconds.
      • For a 6ft 8in cord, measurement should be taken for a minimum of 75 secs.
      • For a 10ft cord, measurement should be taken for a minimum of 80 secs.
      • For a 15ft cord, measurement should be taken for a minimum of 90 secs.
      • For a 25ft cord, measurement should be taken for a minimum of 110 secs.
    6. Record the data on the required form.

    Atmospheric Hazard Testing Video Resources

    What to do if hazards are detected?

    • Make sure to clear the work site of any individuals.
    • Pause the permit; you do not necessarily need to cancel the permit
    • Contact EHS and your supervisor.
    • If possible, make a note of the atmospheric hazard(s).
    • If immediate medical attention is necessary, contact SMU Emergency Dispatch at 214-768-3333.
    • Mitigate the  hazards via ventilation.
    • Re-set the monitor and re-test before starting the permit back up

    Records Management

    It is the manager’s responsibility to ensure the documents are kept up-to date, a copy stored in a Job Safety Analysis Book or Online for employees to utilize and updated copies sent to the EHS group within the Office of Risk Management upon completion and revision.

    Job Safety Analysis Form QF-001-1 is utilized to document the hazard analysis.

    Work units are responsible for maintaining a record of all JSA training provided to their employees.  EHS will maintain records of JSA training provided by EHS personnel.

    SMU EHS will retain each canceled entry permit for at least 1 year to facilitate the review of the permit-required confined space program. Any problems encountered during an entry operation shall be noted on the pertinent permit so that appropriate revisions to the permit space program can be made.

    SMU will perform a single annual review covering all entries performed during a 12-month period. If no entry is performed during a 12-month period, no review is necessary.

    SMU may discard the cancelled entry permits after the review at the discretion of EHS.

    However OSHA’s standard on access to employee exposure and medical records CFR 29 1910.1020 requires the SMU to maintain employee exposure records for at least 30 years.

    If you needed to monitor the entrants’ exposure to toxic substances during the entry, SMU expects you to keep a record of this exposure, report the exposure to the Office of Risk Management as an Incident Report, and SMU EHS will keep the entry permit and all associated documents for 30 years.


    SMU will provide training so that all employees whose work is regulated by this Program EHS S-004, will acquire the understanding, knowledge, and skills necessary for the safe performance of the duties involving confined space entry.

    Awareness level confined space training will be provided initially upon hiring for necessary SMU employees and retraining is required every 3 years.

    SMU has the option of restricting employees from entering permit-required confined spaces. If this is the determination made by SMU, there still remains a responsibility for the SMU to make sure employees are trained at an awareness level about confined spaces in order to prevent employees from entering and working in these spaces.

    Awareness training will address the following:

    • Awareness of the SMU policy and confined space program limiting the employees’ access to confined spaces and their hazards.
    • How to recognize the confined space warning and identification signs.
    • How reclassification works: changes in use or configuration of non-permit spaces that could require the space to be reclassified as a permit-required space.
    • The procedures that address employees of other companies who enter and work in the permit-required confined spaces of the employer.

    When an SMU determines employees will enter and work in permit-required confined spaces the following requirements for training must be met annually:

    Training of a site specific plan that thoroughly address specific hazards and work practices for regularly entered spaces.

    Training specific to the assigned duties involving permit-required confined spaces. This may include how to continuously monitor for hazardous conditions, barricading, emergency action planning, etc.

    Retraining is required annually or if there is a change in confined space duties, if there is a change in operations that may present a new hazard, or  when an SMU representative believes there have been deviations from the confined space entry program or inadequacies in the employees’ knowledge or performance related to the program.

    SMU will keep records of employee training. The training records will include employee name, training date, and the content of the training. Documentation of training will be kept for at least three years from the training date. 

    EHS Group will provide general training to employees. Supervisors are responsible for training their employees on specific confined space entry plans and other hazard controls.