Confined Space

CSB Specific Examples

SJU Specific Examples

29 CFR 1910. 146 - Confined Space Standards


The purpose of this program is to ensure that CSB|OSB employees who enter and perform work in confined spaces found on campus are protected from the hazards associated with confined space entry.


This program must be observed by all CSB|OSB employees authorized to participate in confined space entry operations.

NOTE: CSB|OSB employees may NOT enter permit-required confined spaces, or any such that has hazards detected at or above permissible exposure limits. Employees may enter a permit space, which has been re-classified as non-permit required.  Monitoring instruments must be used prior.


The Occupational Safety and Health Administration under 29 CFR 1910.146 established requirements for practices and procedures to protect employees from the hazards of entry into confined spaces. Examples of confined spaces found on campus include underground storage tanks, boilers, manholes, crawl spaces, electrical vaults, and cooling towers. The hazards that may be associated with these spaces include but are not limited to: hazardous atmospheres, explosive vapors, toxic chemicals, extreme temperatures, risk of drowning, or electrocution.


Attendant:  An individual stationed outside one or more permit spaces who monitors the authorized entrants and who performs all attendant's duties as assigned by this program.

Authorized Entrant:  An individual authorized to enter a permit space.

Confined Space:  A space that:

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

Entry:  The action of passing through an opening into a confined space. Entry includes work activities in that space and occurs as soon as any part of the entrant's body breaks the plane of an opening into the space.

Entry Permit (permit):  The written or printed document that is provided by the employer to allow and control entry into a permit space and that contains specific information for entering the space safely.

Entry Supervisor:  The individual responsible for authorizing entry into a permit space, determining if entry conditions are acceptable, overseeing entry operations, and for terminating or revoking the entry permit.

NOTE:  An entry supervisor may also serve as an authorized entrant, provided the supervisor is trained and equipped as required. Also, the duties of entry supervisor may be passed from one individual to another during the course of an entry operation.

Non-permit-required confined space:  A confined space that does not contain or, with respect to atmospheric hazards, does not have the potential to contain any hazard capable of causing death or serious physical harm.

Permit-Required Confined Space or Permit Space:  A confined space that has one or more of the following characteristics:

  1. It contains or has the potential to contain a hazardous atmosphere.
  2. It contains a material that has the potential for engulfing an entrant.
  3. It has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor, which slopes downward and tapers to a smaller cross-section.
  4. It contains any other recognized serious safety or health hazard.


Environmental Health & Safety (EH&S):

  • Establish the CSB|OSB Confined Space Program in accordance with OSHA's, 29 CFR 1910.146.
  • Assist affected department and personnel in evaluation of confined spaces.
  • Compile and maintain a database of confined spaces and associated hazards.
  • Assist in the training on Confined Space Program.
  • Provide guidance in the proper selection and use of equipment required by this program.
  • Evaluate and measure the air and/or train personnel to perform routine measurement of the air in confined spaces.
  • Audit the implementation of the program and revise as necessary.
  • Maintain copies of the employee training records for the Confined Space Program.

Departments of Public Safety and Fire:

  • Request rescue and emergency services when notified of a confined space emergency.
  • Guide rescue services to the work site.

Participating (Affected) Departments:

  • Identify, evaluate, and classify confined space hazards prior to employee entry.
  • Implement measures necessary to prevent unauthorized entry into permit spaces.
  • Conduct site inspections to review unit compliance with confined space entry procedures.
  • Ensure contractors performing permit space entry have their own confined space programs.


  • Receive training in, and comply with the Confined Space Program.
  • Report any observed program deficiencies and equipment malfunctions to a supervisor.
  • Under no circumstance, enter a confined space that is suspected of having a non-breathable atmosphere, even to rescue a fellow employee.

Employing Contractors:

  • Specify in the bid package or other written information to contractor, when contracting work that involves or may involve entry into a confined space

Precautions and Requirements

  • Barriers, railings, or temporary covers erected to guard confined space openings must be sufficient to prevent a fall through the opening and to protect employees from foreign objects entering the space.
  • Atmospheric testing equipment must be calibrated, direct-reading, and capable of measuring:
    • Oxygen content in the range 19.5% and 23.5%,
    • Flammable gases and vapors 10% of its LFL,
    • Carbon monoxide levels >35 parts per million (ppm), and
    • Hydrogen sulfide levels >10 ppm
  • Gasoline or diesel powered equipment located near proximity to confined space entry points will be placed (or its exhaust ducted) to ensure that exhaust gases do not enter into or contaminate the atmosphere within the confined space.
  • Where the potential exists to encounter flammable and/or explosive substances or atmospheres, all lighting and electrical equipment will be Class 1, Division 1 rated per National Electrical Code.
  • Lockout/Tagout of all energized equipment on which maintenance is to be performed will be in accordance with CSB|OSB "Control of Hazardous Energy Sources (Lockout/Tagout)" program.

Identification and Classification of Confined Spaces

Participating Department Directors/supervisors will identify all confined spaces that fall within their area of supervision. The confined spaces must be evaluated for hazards (both known and potential) and subsequently classified as one of the following:

  • Non-Permit-Required Confined Space, or
  • Permit-Required Confined Space (Permit Space)

The confined space will be classified as a Permit-Required Confined Space (Permit Space) if it is known or suspected to present one or more of the following hazardous conditions:

  • Oxygen deficient atmosphere (<19.5 percent)
  • Oxygen enriched atmosphere (>23.5 percent)
  • Airborne combustible dust at a concentration > its LFL/LEL
  • Flammable atmosphere (gas, vapor, or mist >10% of its LFL/LEL)
  • Atmospheric toxin > its PEL or TLV
  • Any other atmospheric condition that is immediately dangerous to life or health
  • Machinery/equipment hazards
  • Extreme temperature hazards
  • Engulfment hazards
  • Electrocution hazards
  • Extreme noise hazards
  • Any other hazards capable of causing death or serious injury

CAUTION:  In the course of identifying and evaluating confined spaces, DO NOT ENTER any space known or suspected of containing any hazard listed above.

A database of campus located confined spaces that lists for each space: a brief description of the space, its location on campus, its classification, the associated hazards reported, and the name and telephone number of the Department Director or Manager who controls entry into the space, shall be maintained and made accessible to authorized personnel.

Participating Department Directors or Managers will inform employees of the existence, location, and dangers posed by permit spaces by posting a warning sign at the entrance to the permit space. The sign will read:


Where it is not possible to post a warning notice visible from outside the entry point (e.g., manholes) the sign will be posted at a location that is immediately visible upon opening of the entry point.

CSB employees are not authorized to enter any permit spaces.

Confined Space Entry Procedures

The hazards associated with entry to a confined space vary in degree (from least to most severe) as follows:

  • A non-permit space which, by definition, does not contain any serious safety hazard,
  • A permit-required space in which all hazards are eliminated prior to any entry,
  • A permit space wherein the only hazard is atmospheric, and for which continuous, forced-air ventilation alone is sufficient to control, and
  • A permit space that contains or has the potential to contain, both atmospheric and non-atmospheric (physical) hazards.

Entry into a Non-Permit-Required Confined Space

A non-permit-required confined space, by definition, poses no hazard to an employee more serious than its restricted means of entry and exit. Therefore, provided that the work to be performed lacks any potential to create a prohibited or unacceptable condition, entry to a Non-Permit-Required confined space may proceed as described below.

Prior to entry:

  1. Review the work order to determine requirements for personal protective equipment,
  2. If applicable, establish traffic control at the entry point,
  3. Eliminate any condition making it unsafe to remove the confined space entry cover, and
  4. Once the entry cover is removed, promptly guard the entry point with a temporary barrier to prevent an accidental fall through the opening and to protect employees working in the space from foreign objects entering the space.

NOTE:  If the work to be performed in the space has potential to create a prohibited or unacceptable condition, do NOT enter the space.

Reclassification from Permit-Required to Non-Permit-Required, Prior to Entry

Under certain conditions the Entry Supervisor may temporarily reclassify a permit space as non-permit-required. This action can facilitate entry to the space by reducing the entry requirements. The specific conditions necessary to allow this temporary reclassification are that:

A: All hazards within the permit space be eliminated prior to entry, and

B: The space poses no atmospheric hazard (actual or potential) during entry.

Condition (a) calls for elimination of all hazards through isolation techniques such as lockout/tagout, line blocking, purging, etc., which must be accomplished without having to enter the space. (See Section Atmospheric Testing).

Condition (b) requires that any atmospheric hazard eliminated by condition (a) remain eliminated throughout the duration of the entry operation. Note that the use of continuous forced air ventilation to control an atmospheric hazard does not "eliminate" the hazard and thus, does not constitute compliance with this condition.

The Entry Supervisor must prepare a Permit Space Reclassification Certificate that documents the basis for determining that all hazards in the space have been eliminated. The certification is then made available to all employees entering the space by posting of the certificate at the entry point to the space.

The reclassification remains valid only for as long as the hazards remain eliminated. If a hazard arises within a declassified space, all employees must exit the space immediately and the space be reevaluated to determine whether it must once again be classified as permit-required.

Entry into a permit space reclassified as Non-Permit-Required will proceed as detailed below.

Prior to entry, the Entry Supervisor will:

  1. Prepare a Permit Space Reclassification Certificate
  2. Post the Permit Space Reclassification Certificate at the entry point.
  3. If applicable, establish traffic control at the entry point.
  4. Eliminate or isolate all hazards within the space prior to removal of the permit space entry cover.
  5. Once the entry cover is removed, promptly guard the entry point with a temporary barrier to prevent a fall through the opening and to protect employees working in the space from foreign objects entering the space.

NOTE:  If any prohibited condition is detected during entry, all employees will immediately evacuate the space and the Entry Supervisor will:

  • Evaluate the space to determine how the prohibited condition developed, and
  • Implement measures to eliminate the prohibited condition and prevent its recurrence before any subsequent re-entry.

Upon completion of entry, the Entry Supervisor will:

  • Ensure that the space is properly closed and returned to service.
  • Terminate the Reclassification Certificate and forward it to EH&S.


A Reclassification Certificate is used to conduct safe entry into permit spaces reclassified as non-permit-required. The Entry Supervisor performing a reclassification as detailed in above, will prepare a Reclassification Certificate prior to any initial entry into the permit space. Copies of such certificate must be made available to EH&S.

Duration of Reclassification Certificate

Unless revoked for cause by the Entry Supervisor, a Reclassification Certificate remains valid for the duration of the entry operation or for a single, eight-hour work shift. If necessary, the certificate may be extended for over-time work performed by the same entry crew.

Revocation of Reclassification Certificate

The Entry Supervisor will immediately revoke the Reclassification Certificate and notify employees to evacuate the space upon detection of a prohibited condition in or around the space. Likewise, the certificate will be immediately revoked and evacuation ordered if work activities deviate from those described on the certificate in a manner that threatens to introduce a hazard in or around the permit space.

Posting of Reclassification Certificate

The Reclassification Certificate will be made available for review by all employees actively involved with the entry operation by posting the certificate at the permit space entry point.

Termination and Disposition of Reclassification Certificate

The Entry Supervisor will terminate (cancel) the Reclassification Certificate upon completion of the entry operation and forward a copy of the canceled certificate to EH&S. Each canceled certificate will be retained for at least 1 year by EH&S to facilitate the review of the Confined Space Program. Any problems encountered during an entry operation will be noted on the pertinent certificate so that appropriate revisions to the program can be made.

Atmospheric Testing

Atmospheric testing is required to evaluate the hazards of the permit space, to verify that acceptable atmospheric conditions exist in the permit space prior to entry, and to ensure that atmospheric conditions remain acceptable throughout the duration of the entry operation.

Specification of Acceptable Atmospheric Conditions

Acceptable atmospheric conditions in CSB|OSB permit spaces will meet the following specifications:

  • Oxygen Content: must fall within the range 19.5% through 23.5%,
  • Flammability: must not exceed 10% of the lower flammable limit (LFL) for the particular gas, vapor, or mist that is present in the atmosphere,
  • Airborne Combustible Dust:  must not meet or exceed the LEL for the particular combustible dust that is present in the atmosphere,
  • Carbon Monoxide: must not exceed 35 ppm (parts per million),
  • Hydrogen Sulfide: must not exceed 10 ppm, and
  • Other Toxins:  must be below the dose or exposure limit for the particular material, as published in 29CFR1910 Subpart G, Occupational Health and Environmental Control, or in Subpart Z, Toxic and Hazardous Substances.

NOTE:  For air contaminants for which OSHA has not determined a dose or permissible exposure limit, other sources of information, such as Material Safety Data Sheets, published information, and internal documents can provide guidance in establishing acceptable atmospheric conditions.

Evaluation/Verification Testing

To re-classify a permit space as non-permit required, the atmosphere of the space will be analyzed using a calibrated, direct reading, gas monitor of sufficient sensitivity and specificity to identify and evaluate any hazardous atmospheric condition that is known or suspected to exist. At a minimum, tests will be conducted to evaluate:

  • Oxygen Content
  • Flammability
  • Toxicity (carbon monoxide and hydrogen sulfide)

Toxicity tests for substances other than carbon monoxide and hydrogen sulfide will be required only if other toxins are known or suspected to be present in the permit space.

Contractor Confined Space Entry

Contractor entry operations into a CSB|OSB permit-required confined space will be performed under the contractor's own Confined Space Program. Contractors will be required to submit to the CSB|OSB Project Manager a copies of their Confined Space Programs prior to any entry.

It is the responsibility of each contractor who performs entry operations to obtain any available information regarding confined space hazards and entry operations from CSB|OSB. Contractors must also coordinate entry operations with CSB|OSB when both CSB|OSB and contractor personnel will be working in or near permit spaces.

Coordinating Entry Operations

The CSB|OSB Project Manager will inform contractors of CSB|OSB 's safety rules and emergency plans which may be applicable to the contractors' employees. Contractors and their employees must not be allowed to enter a permit-required confined space until the provisions of this program have been satisfied. When both CSB|OSB and contractor personnel are working in or near permit-required confined spaces, entry operations must be coordinated to avoid endangering any personnel.

All contractors performing entry into a permit-space will be informed of any fire, explosion, health or other safety hazards of that confined space. This information will be based on current or past history of the confined space and the nature of the work being performed by the contractor.


Each contractor who enters a permit required space is responsible for rescue operations in case of an emergency. In addition, the Fire Department that has jurisdiction, will be notified of the emergency and will be made aware of the hazards they may confront when called on to perform rescues. Upon request, CSB|OSB will provide the Fire Department with access to all permit-required confined spaces from which rescue may be necessary so that they can develop appropriate rescue plans and practice rescue operations.

If an injured entrant is exposed to a substance for which a Material Safety Data Sheet (MSDS) or other similar written information is required to be kept at the work site, that MSDS or written information will be made available to the medical facility treating the exposed entrant.


The Environmental Health & Safety will assist in providing training so that all employees whose work is regulated by this program acquire the understanding, knowledge, and skills necessary for the safe performance of the duties assigned.

Training will be provided to each affected employee:

  • Before the employee is first assigned duties.
  • Before there is a change in assigned duties.
  • Whenever there is reason to believe either that there are deviations from the Confined Space Program entry procedures or that there are inadequacies in the employee's knowledge or use of these procedures.

Training will ensure employee proficiency in the duties required by 29 CFR 1910.146 and will include new or revised procedures, as necessary, to maintain compliance with this program.

EH&S will certify that the training required by the previously mentioned paragraphs has been accomplished. The certification will contain each employee’s name, the signatures or initials of the trainers, and the dates of training. The certification will be available for inspection by employees and their authorized representatives. However, employees will not be trained to enter permit required confined spaces.

Confined Space Program Review

The department management or EH&S will review entry operations when there is reason to believe that the measures prescribed in the Confined Space Program may fail to protect employees and revise the program to correct deficiencies found to exist before any subsequent entries are authorized.

Examples of circumstances requiring review of the program are:

  • Any unauthorized entry to a permit space,
  • The occurrence of an injury or "near-miss" during entry,
  • A change in the use or configuration of a confined space, and
  • Employee complaints about the effectiveness of the program.

EH&S will perform an annual review covering all entries performed in the twelve month period as part of the program review.