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OSHA Confined Spaces Advisor

Overview of the Permit-Required Confined Spaces Standard

The Final Rule for Permit-Required Confined Spaces was published in the Federal Register on January 14, 1993, and became effective on April 15, 1993. The standard is based on years of gathering information on confined space fatalities and on testimony about the hazards of confined spaces from all sectors of industry and labor. Because it applies to all of general industry, a performance-oriented standard was developed rather than a specification standard. The rule citation is 29CFR1910.146.

Many workplaces contain spaces which are considered "confined" because their configurations hinder the activities of any employees who must enter, work in, and exit them. For example, employees who work in process vessels generally must squeeze in and out through narrow openings and perform their tasks while cramped or contorted. For the purposes of this rulemaking, OSHA is using the term "confined space" to describe such spaces.

In addition, there are many instances where employees who work in confined spaces face increased risk of exposure to serious hazards. In some cases, confinement itself poses entrapment hazards. In other cases, confined space work keeps employees closer to hazards, such as asphyxiating atmospheres or the moving parts of a mixer, than they would be otherwise.

OSHA uses the term "permit-required confined space" (permit space) to describe those spaces which both meet the definition of "confined space" and pose health or safety hazards.

Asphyxiation is the leading cause of death in confined spaces. The asphyxiation that have occurred in permit spaces have generally resulted from oxygen deficiency or from exposure to toxic atmospheres. In addition, there have been cases where employees who were working in water towers and bulk material hoppers slipped or fell into narrow, tapering, discharge pipes and died of asphyxiation due to compression of the torso. Also, employees working in silos have been asphyxiated as the result of engulfment in finely divided particulate matter (such as sawdust) that blocks the breathing passages.

OSHA has, in addition, documented confined space incidents in which victims were burned, ground-up by auger type conveyors, or crushed or battered by rotating or moving parts inside mixers. Failure to deenergize equipment inside the space prior to employee entry was a factor in many of those accidents.

Many employers have not appreciated the degree to which the conditions of permit space work can compound the risks of exposure to atmospheric or other serious hazards. Further, the elements of confinement, limited access, and restricted air flow, can result in hazardous conditions which would not arise in an open workplace. For example, vapors which might otherwise be released into the open air can generate a highly toxic or otherwise harmful atmosphere within a confined space. Unfortunately, in many cases, employees have died because employers improvised or followed "traditional methods" rather than following existing OSHA standards, recognized safe industry practice, or common sense.

The failure to take proper precautions for permit space entry operations has resulted in fatalities, as opposed to injuries, more frequently than would be predicted using the applicable Bureau of Labor Statistics models. OSHA notes that, by their very nature and configuration, many permit spaces contain atmospheres which, unless adequate precautions are taken, are immediately dangerous to life and health (IDLH). For example, many confined spaces are poorly ventilated - a condition that is favorable to the creation of an oxygen deficient atmosphere and to the accumulation of toxic gases.

Furthermore, by definition, a confined space is not designed for continuous employee occupancy; hence little consideration has been given to the preservation of human life within the confined space when employees need to enter it.

It is your obligation as an employer to evaluate your workplace to determine if any spaces are permit-required confined spaces. Based on your answers during this session Confined Spaces Advisor has concluded that the specific space in question is such a space.

REMINDER: A confined space is characterized by restricted means of entry/exit, size sufficient to contain a worker, and not specifically designed for worker occupancy. A permit-required space is a confined space that has a hazard to health or life associated with it. Hazards may be the result of atmosphere or materials in the space or the result of the shape of the space.

In general, the Permit-Required Confined Spaces standard requires that you, the employer, evaluate the workplace to determine if any spaces are permit-required confined spaces. If permit spaces are present, and your workers are ever authorized to enter such spaces (you said they do) you must develop and implement a comprehensive permit spaces program, which is a an overall plan/policy for protecting employees form permit space hazards and for regulating employee entry into permit spaces. The OSHA standard includes detailed specification of the elements of an acceptable permit spaces program (29CFR1910.146(d)).

Permit spaces must be identified by signs, and entry must be controlled and limited to authorized persons. An important element of the requirements is that entry be regulated by a written entry permit system, and that entry permits be recorded and issued for each entry in to a permit space. The standard specifies strict procedures for evaluation and atmospheric testing of a space before and during an entry by workers. The standard requires that entry be monitored by an attendant outside the space and that provisions be made for rescue in the event of an emergency. The standard specifies training requirements and specific duties for authorized entrants, attendants, and supervisors. Rescue service provisions are required, and where feasible rescue must be facilitated by a non-entry retrieval system, such as a harness and cable attached to a mechanical hoist.

The OSHA Permit-Required Spaces Standard provides for alternative (less stringent than full permit procedures) entry procedures in cases where the only hazard in a space is atmospheric and the hazard can be controlled by forced air. The alternative procedure is allowed only in cases where specified requirements for substantiation and notification are met. Your answers during this session with the Confined Spaces Advisor indicated that you are not eligible to apply the alternative procedures to the space in question.

Special requirements apply to contractors whose employees work in spaces controlled by others. Employers who engage contractors to work in their permit-required confined spaces also have special obligations pertaining to that arrangement.

If certain kinds of work are done in a permit space, then additional OSHA rules may apply. These kinds of work include telecommunications, electrical (underground), paper/pulp milling, shipbuilding, longshoring, and sewer work. Confined Spaces Advisor asked you to identify applicable kinds of work done in the permit space, and has appended additional guidance at the end of this report if you indicated any of the critical kinds of work.

Construction, ship yard or marine terminal employment, and agriculture are not subject to the OSHA General Industry Permit-required Confined Spaces regulation (29CFR1910.146). However, employers in those industries should be aware that their workers are covered when they do work that falls under the general industry category. For example, maintenance, repair, and refurbishing work is covered under general industry rules even though done by "construction" contractors.

You may be able to reclassify a permit-required confined space to non-permit space status if you can permanently eliminate the hazards affecting the space.

Detailed Guidance

The following twenty five items describe provisions of the Permit-required Confined Spaces rule that apply to operations involving the space in question. The text follows closely the language of 29CFR1910.146, but has been edited to present only material relevant to the case described and to organize material in a useful sequence. Use Confined Spaces Advisor Option 6 to view the official text of 29CFR1910.146.

  1. The employer shall evaluate the workplace to determine if any spaces are permit-required confined spaces.

  2. If the workplace contains permit spaces, the employer shall inform exposed employees, by posting danger signs or by any other equally effective means, of the existence and location of and the danger posed by the permit spaces. NOTE: A sign reading DANGER -- PERMIT-REQUIRED CONFINED SPACE, DO NOT ENTER or using other similar language would satisfy the requirement for a sign.

  3. If the employer decides that its employees will enter permit spaces, the employer shall develop and implement a written permit space program that complies with this section. The written program shall be available for inspection by employees and their authorized representatives. The permit space program must include the fourteen elements specified in 29CFR1910.146(d). These elements correspond to items 4 through 17 in this guidance report.

  4. The employer shall implement the measures necessary to prevent unauthorized entry;

  5. The employer shall identify and evaluate the hazards of permit spaces before employees enter them;

  6. The employer shall develop and implement the means, procedures, and practices necessary for safe permit space entry operations, including, but not limited to, the following:
    1. Specifying acceptable entry conditions;
    2. Isolating the permit space;
    3. Purging, inerting, flushing, or ventilating the permit space as necessary to eliminate or control atmospheric hazards;
    4. Providing pedestrian, vehicle, or other barriers as necessary to protect entrants from external hazards; and
    5. Verifying that conditions in the permit space are acceptable for entry throughout the duration of an authorized entry.

  7. The employer shall provide the following equipment at no cost to employees, maintain that equipment properly, and ensure that employees use that equipment properly:
    1. Testing and monitoring equipment needed to comply with requirements of this section;
    2. Ventilating equipment needed to obtain acceptable entry conditions;
    3. Communications equipment necessary to allow entrants and attendants to communicate and monitor conditions in the space (see 29CFR1910.146(h)(3) and (i)(5) regarding the duties of attendants and entrants to communicate);
    4. Personal protective equipment insofar as feasible engineering and work practice controls do not adequately protect employees;
    5. Lighting equipment needed to enable employees to see well enough to work safely and to exit the space quickly in an emergency;
    6. Barriers and shields as required by 29CFR1910.146(d)(3) (see item v, above);
    7. Equipment, such as ladders, needed for safe ingress and egress by authorized entrants;
    8. Rescue and emergency equipment needed to comply with 29CFR1910.146(d)(9), except to the extent that the equipment is provided by rescue services; and
    9. Any other equipment necessary for safe entry into and rescue from permit spaces.

  8. The program shall evaluate permit space conditions as follows when entry operations are conducted:
    1. Test conditions in the permit space to determine if acceptable entry conditions exist before entry is authorized to begin, except that, if isolation of the space is infeasible because the space is large or is part of a continuous system (such as a sewer), pre-entry testing shall be performed to the extent feasible before entry is authorized and, if entry is authorized, entry conditions shall be continuously monitored in the areas where authorized entrants are working;
    2. Test or monitor the permit space as necessary to determine if acceptable entry conditions are being maintained during the course of entry operations; and
    3. When testing for atmospheric hazards, test first for oxygen, then for combustible gases and vapors, and then for toxic gases and vapors.
    4. NOTE: Atmospheric testing conducted in accordance with Appendix B to section 1910.146 would be considered as satisfying the requirements of this paragraph. For permit space operations in sewers, atmospheric testing conducted in accordance with Appendix B, as supplemented by Appendix E to section 1910.146, would be considered as satisfying the requirements of this paragraph.

  9. The program shall provide at least one attendant outside the permit space into which entry is authorized for the duration of entry operations; NOTE: Attendants may be assigned to monitor more than one permit space provided the duties described in paragraph (i) of this section can be effectively performed for each permit space that is monitored. Likewise, attendants may be stationed at any location outside the permit space to be monitored as long as the duties described in paragraph (i) of this section can be effectively performed for each permit space that is monitored.

  10. If multiple spaces are to be monitored by a single attendant, include in the permit program the means and procedures to enable the attendant to respond to an emergency affecting one or more of the permit spaces being monitored without distraction from the attendant's responsibilities under paragraph (i) of this section;

  11. Designate the persons who are to have active roles (as, for example, authorized entrants, attendants, entry supervisors, or persons who test or monitor the atmosphere in a permit space) in entry operations, identify the duties of each such employee, and provide each such employee with the training required by paragraph (g) of this section;

  12. Develop and implement procedures for summoning rescue and emergency services, for rescuing entrants from permit spaces, for providing necessary emergency services to rescued employees, and for preventing unauthorized personnel from attempting a rescue;

  13. Develop and implement a system for the preparation, issuance, use, and cancellation of entry permits as required by this section;

  14. Develop and implement procedures to coordinate entry operations when employees of more than one employer are working simultaneously as authorized entrants in a permit space, so that employees of one employer do not endanger the employees of any other employer;

  15. Develop and implement procedures (such as closing off a permit space and canceling the permit) necessary for concluding the entry after entry operations have been completed;

  16. Review entry operations when the employer has reason to believe that the measures taken under the permit space program may not protect employees and revise the program to correct deficiencies found to exist before subsequent entries are authorized; NOTE: Examples of circumstances requiring the review of the permit space program are: any unauthorized entry of a permit space, the detection of a permit space hazard not covered by the permit, the detection of a condition prohibited by the permit, the occurrence of an injury or near-miss during entry, a change in the use or configuration of a permit space, and employee complaints about the effectiveness of the program.

  17. Review the permit space program, using the canceled permits retained (as provided by 29CFR1910.146 (e)(6)), within 1 year after each entry and revise the program as necessary, to ensure that employees participating in entry operations are protected from permit space hazards. NOTE: Employers may perform a single annual review covering all entries performed during a 12-monthperiod. If no entry is performed during a 12-month period, no review is necessary. Appendix C to section 1910.146 presents examples of permit space programs that are considered to comply with the requirements of paragraph (d) of this section.

  18. Permit system (see 29CFR1910.146 (e)). The following six-step procedure must be followed for each entry into the permit space.
    1. Before entry is authorized, the employer shall document the completion of measures, procedures, and practices necessary for safe permit space entry (listed under item (6) of this guidance report and in 29CFR1910.146(d)(3)) by preparing an entry permit. NOTE: Appendix D to section 1910.146 (Accessible through the Advisor system options) presents examples of permits whose elements are considered to comply with the requirements of this section.
    2. Before entry begins, the entry supervisor identified on the permit shall sign the entry permit to authorize entry.
    3. The completed permit shall be made available at the time of entry to all authorized entrants, by posting it at the entry portal or by any other equally effective means, so that the entrants can confirm that pre-entry preparations have been completed.
    4. The duration of the permit may not exceed the time required to complete the assigned task or job identified on the permit.
    5. The entry supervisor shall terminate entry and cancel the entry permit when the entry operations covered by the entry permit have been completed; or when a condition that is not allowed under the entry permit arises in or near the permit space.
    6. The employer shall retain each canceled entry permit for at least 1 year to facilitate the review of the permit -required confined space program required by 29CFR1910.146(d)(14). 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.

  19. Entry Permit Requirements (as specified in 29CFR1910.146(f)). The entry permit that documents compliance with the permit-required confined spaces standard and authorizes entry to a permit space shall identify the following fifteen items:
    1. The permit space to be entered;
    2. The purpose of the entry;
    3. The date and the authorized duration of the entry permit;
    4. The authorized entrants within the permit space, by name or by such other means (for example, through the use of rosters or tracking systems) as will enable the attendant to determine quickly and accurately, for the duration of the permit, which authorized entrants are inside the permit space; NOTE: This requirement may be met by inserting a reference on the entry permit as to the means used, such as a roster or tracking system, to keep track of the authorized entrants within the permit space.
    5. The personnel, by name, currently serving as attendants;
    6. The individual, by name, currently serving as entry supervisor, with a space for the signature or initials of the entry supervisor who originally authorized entry;
    7. The hazards of the permit space to be entered;
    8. The measures used to isolate the permit space and to eliminate or control permit space hazards before entry; NOTE: Those measures can include the lockout or tagging of equipment and procedures for purging, inerting, ventilating, and flushing permit spaces.
    9. The acceptable entry conditions;
    10. The results of initial and periodic tests performed under 29CFR1910.146(d)(5) (see prior item (8) of this report), accompanied by the names or initials of the testers and by an indication of when the tests were performed;
    11. The rescue and emergency services that can be summoned and the means (such as the equipment to use and the numbers to call) for summoning those services;
    12. The communication procedures used by authorized entrants and attendants to maintain contact during the entry;
    13. Equipment, such as personal protective equipment, testing equipment, communications equipment, alarm systems, and rescue equipment, to be provided for compliance with this section; Note: equipment must be provided to insure communication between the attendant outside the space and workers within the space;
    14. Any other information whose inclusion is necessary, given the circumstances of the particular confined space, in order to ensure employee safety; and
    15. Any additional permits, such as for hot work, that have been issued to authorize work in the permit space.

  20. Training (as specified in 29CFR1910.146(g)). The employer shall provide training so that all employees whose work is regulated by this section acquire the understanding, knowledge, and skills necessary for the safe performance of the duties assigned under the permit spaces standard. Training shall be provided to each affected employee:
    1. Before the employee is first assigned duties under this section;
    2. Before there is a change in assigned duties;
    3. Whenever there is a change in permit spaceoperations that presents a hazard about which anemployee has not previously been trained;
    4. Whenever the employer has reason to believe either that there are deviations from the permit space entry procedures required by the permits spaces program (see 29CFR1910.146(d)(3) or prior item (6) of this report) or that there are inadequacies in the employee's knowledge or use of these procedures. The training shall establish employee proficiency in the duties required by the 29CFR1910.146 standard and shall introduce new or revised procedures, as necessary, for compliance with the permit spaces standard. The employer shall certify that the training required the standard (described in this section) has been accomplished. The certification shall contain each employee's name, the signatures or initials of the trainers, and the dates of training. The certification shall be available for inspection by employees and their authorized representatives.

  21. The Five Duties of Authorized Entrants (as specified in 29CFR1910.146(h)). The employer shall ensure that all authorized entrants:
    1. Know the hazards that may be faced during entry, including information on the mode, signs or symptoms, and consequences of the exposure;
    2. Properly use equipment (see prior item (7) or 29CFR1910.146 (d)(4) for the list of equipment);
    3. Communicate with the attendant as necessary to enable the attendant to monitor entrant status and to enable the attendant to alert entrants of the need to evacuate the space (see also duties of attendants described in item 22, below, or in 29CFR1910.146(i)(6) of the standard);
    4. Alert the attendant whenever: The entrant recognizes any warning sign or symptom of exposure to a dangerous situation, or the entrant detects a prohibited condition; and
    5. Exit from the permit space as quickly as possible whenever: An order to evacuate is given by the attendant or the entry supervisor; the entrant recognizes any warning sign or symptom of exposure to a dangerous situation; the entrant detects a prohibited condition, or an evacuation alarm is activated.

  22. The Ten Duties of Attendants (as specified in 29CFR1910.146(i)). The employer shall ensure that each attendant:
    1. Knows the hazards that may be faced during entry, including information on the mode, signs or symptoms, and consequences of the exposure;
    2. Is aware of possible behavioral effects of hazard exposure in authorized entrants;
    3. Continuously maintains an accurate count of authorized entrants in the permit space and ensures that the means used to identify authorized entrants accurately identifies who is in the permit space;
    4. Remains outside the permit space during entry operations until relieved by another attendant; NOTE: When the employer's permit entry program allows attendant entry for rescue, attendants may enter a permit space to attempt a rescue if they have been trained and equipped for rescue operations (see rescue requirements below or 29CFR1910.146 (k)(1) for details) and if they have been relieved as required by this section;
    5. Communicates with authorized entrants as necessary to monitor entrant status and to alert entrants of the need to evacuate the space;
    6. Monitors activities inside and outside the space to determine if it is safe for entrants to remain in the space and orders the authorized entrants to evacuate the permit space immediately under any of the following conditions: If the attendant detects a prohibited condition; If the attendant detects the behavioral effects of hazard exposure in an authorized entrant; If the attendant detects a situation outside the space that could endanger the authorized entrants; or If the attendant cannot effectively and safely perform all the duties required of entrants (see item 21 above);
    7. Summon rescue and other emergency services as soon as the attendant determines that authorized entrants may need assistance to escape from permit space hazards;
    8. Takes the following actions when unauthorized persons approach or enter a permit space while entry is underway: Warn the unauthorized persons that they must stay away from the permit space; Advise the unauthorized persons that they must exit immediately if they have entered the permit space; and Inform the authorized entrants and the entry supervisor if unauthorized persons have entered the permit space;
    9. Performs non-entry rescues as specified by the employer's rescue procedure; and
    10. Performs no duties that might interfere with the attendant's primary duty to monitor and protect the authorized entrants.

  23. The Six Duties of Entry Supervisors (29CRF1910.146(j). The employer shall ensure that each entry supervisor:
    1. Knows the hazards that may be faced during entry, including information on the mode, signs or symptoms, and consequences of the exposure;
    2. Verifies, by checking that the appropriate entries have been made on the permit, that all tests specified by the permit have been conducted and that all procedures and equipment specified by the permit are in place before endorsing the permit and allowing entry to begin;
    3. Terminates the entry and cancels the permit as required by paragraph (e)(5) of this section;
    4. Verifies that rescue services are available and that the means for summoning them are operable;
    5. Removes unauthorized individuals who enter or who attempt to enter the permit space during entry operations; and
    6. Determines, whenever responsibility for a permit space entry operation is transferred and at intervals dictated by the hazards and operations performed within the space, that entry operations remain consistent with terms of the entry permit and that acceptable entry conditions are maintained.

  24. Rescue and emergency services (29CFR1910.146(k)) NOTE: OSHA is has initiated rule making procedures to clarify certian aspects of rescue requirements and procedures.. There are two ways in which rescue services may be provided: By employees of the subject employer or by employees of a second party rescue service. The following requirements apply to employers who have employees enter permit spaces to perform rescue services.
    1. The employer shall ensure that each member of the rescue service is provided with, and is trained to use properly, the personal protective equipment and rescue equipment necessary for making rescues from permit spaces.
    2. Each member of the rescue service shall be trained to perform the assigned rescue duties. Each member of the rescue service shall also receive the training required of authorized entrants.
    3. Each member of the rescue service shall practice making permit space rescues at least once every 12 months, by means of simulated rescue operations in which they remove dummies, manikins, or actual persons from the actual permit spaces or from representative permit spaces. Representative permit spaces shall, with respect to opening size, configuration, and accessibility, simulate the types of permit spaces from which rescue is to be performed.
    4. Each member of the rescue service shall be trained in basic first-aid and in cardiopulmonary resuscitation (CPR). At least one member of the rescue service holding current certification in first aid and in CPR shall be available.
    When an employer (host employer) arranges to have persons other than the host employer's employees perform permit space rescue, the host employer shall:
    1. Inform the rescue service of the hazards they may confront when called on to perform rescue at the host employer's facility, and
    2. Provide the rescue service with access to all permit spaces from which rescue may be necessary so that the rescue service can develop appropriate rescue plans and practice rescue operations.
    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. Retrieval systems shall meet the following requirements.
    1. Each authorized entrant shall use a chest or full body harness, with a retrieval line attached atthe center of the entrant's back near shoulder level, or above the entrant's head. Wristlets may be used in lieu of the chest or full body harness if the employer can demonstrate that the use of a chest or full body harness is infeasible or creates a greater hazard and that the use of wristlets is the safest and mosteffective alternative.
    2. The other end of the retrieval line shall beattached to a mechanical device or fixed point outside the permit space in such a manner that rescue can begin as soon as the rescuer becomes aware that rescue is necessary. A mechanical device shall be available to retrieve personnel from vertical type permit spaces more than 5 feet (1.52 m) deep.
    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 worksite, that MSDS or written information shall be made available to the medical facility treating the exposed entrant.

  25. When an employer (host employer) arranges to have employees of another employer (contractor) perform work that involves permit space entry, the host employer shall:
    1. Inform the contractor that the workplace contains permit spaces and that permit space entry is allowed only through compliance with a permit space program meeting the requirements of this section;
    2. Apprise the contractor of the elements, including the hazards identified and the host employer's experience with the space, that make the space in question a permit space;
    3. Apprise the contractor of any precautions or procedures that the host employer has implemented for the protection of employees in or near permit spaces where contractor personnel will be working;
    4. Coordinate entry operations with the contractor, when both host employer personnel and contractor personnel will be working in or near permit spaces so that employees of one employer do not endanger the employees of any other employer; and
    5. Debrief the contractor at the conclusion of the entry operations regarding the permit space program followed and regarding any hazards confronted or created in permit spaces during entry operations.

You may be able to declassify the permit space if the hazard can be eliminated. Use Confined Spaces Advisor's Special Topics Option for detailed information.