Does "Subpart AA - Confined Spaces in Construction" Apply to You?

Subpart AA provides the standards for confined spaces in the construction industry. According to the scope, examples of locations where confined spaces may occur include, but are not limited to, the following: Bins; boilers; pits (such as elevator, escalator, pump, valve or other equipment); manholes (such as sewer, storm drain, electrical, communication, or other utility); tanks (such as fuel, chemical, water, or other liquid, solid or gas); incinerators; scrubbers; concrete pier columns; sewers; transformer vaults; heating, ventilation, and air-conditioning (HVAC) ducts; storm drains; water mains; precast concrete and other pre-formed manhole units; drilled shafts; enclosed beams; vessels; digesters; lift stations; cesspools; silos; air receivers; sludge gates; air preheaters; step up transformers; turbines; chillers; bag houses; and/or mixers/reactors. This subpart does not apply to:

  • Construction work regulated by subpart P - excavations
  • Construction work regulated by subpart S - underground construction, caissons, cofferdams and compressed air
  • Construction work regulated by subpart Y - commercial diving operations

Using the definitions below, are your employees engaged in construction work involving confined spaces? If yes, you need to comply with this subpart, and specifically, the standard on general requirements which includes having a competent person evaluate all confined spaces and permit spaces. It also includes requirements pertaining to posting danger signs, preventing entry, written permit space program, alternate procedures (i.e., isolating/eliminating hazards through engineering controls, ventilation), reevaluation of spaces by competent person, entry communication and coordination, and multi-employer roles (reference CPL 2-0.124 - multi-employer worksite policy).

Confined space means a space that:

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

Permit-required confined space (permit space) means 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 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; or
  • Contains any other recognized serious safety or health hazard.

Competent person means one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has the authorization to take prompt corrective measures to eliminate them.

Are your employees (entrants) entering permit spaces? Are your employees providing duties as entry supervisors or as attendants? Are your employees providing emergency services or rescue for permit space entry? If yes, click on the tabs below for more information regarding the requirements for permit space entry. Note: If your employees are not entering permit spaces, you must take effective measures to prevent their entry.

This subpart also provides a standard on employee participation which provides requirements for obtaining employee consultation on the permit space program and making all information required by the standard available to them as well as the standard on provision of documents to secretary which requires that each document also be available to OSHA.

More information can be found on the A-Z safety and health topics page for confined spaces.

Subpart AA - Confined Spaces in Construction

Are your employees entering permit spaces?

Are your employees entering permit spaces?

If yes, then you need to comply with the permit-required confined space program standard. It provides the requirements for the permit space program including preventing unauthorized entry, identifying and evaluating spaces, developing and implementing permit space entry operations, equipment provisions, evaluating permit space conditions, providing an outside attendant, identify roles (i.e., entrants, attendants, entry supervisors, monitors), rescue and emergency services, use of entry permits, procedures for entry operations, review of entry operations for deficiencies, and review of permit space program.  

In addition, you need to comply with the standards pertaining to entry permits; permitting process and entry permit. The permitting process standard provides requirements pertaining to documented entry permits, signing permits by entry supervisor, posting entry permits, permit duration, terminating entry (i.e., canceling permits, suspending permits), and retention of canceled entry permits (one year).  The entry permit standard provides the requirements for the permits including documentation for entry purpose, date of entry, authorized duration, acceptable entry conditions, monitoring results, rescue services, hazards present, communication procedures, equipment (i.e., personal protective equipment, testing equipment, communications equipment, alarms), safety measures, additional permits (i.e., hot work permits) and names of entrants, attendants, and entry supervisor.

More information can be found on the A-Z safety and health topics page for confined spaces and personal protective equipment.

Are your employees performing duties as an authorized entrant?

Are your employees performing duties as an authorized entrant?

If yes, then you need to comply with the standard on duties of authorized entrants. This standard includes requirements pertaining to the entrant being familiar with the hazards faced during entry (i.e., mode, signs and symptoms of exposure), using of equipment, communication with attendants, when to alert attendant, and when to exit quickly (i.e., alarms, symptoms of exposure). 

You also need to comply with the standard on training which requires that all employees involved in confined space entry are properly trained (i.e., possesses the understanding, knowledge, and skills necessary for the safe performance of the duties), and that the employer ensures employee proficiency. All training records are to be maintained for the period of time the employee is employed by the employer. 

More information can be found on the A-Z safety and health topics page for confined spaces.

Are employees performing duties as an authorized attendants?

Are employees performing duties as an authorized attendants?

If yes, then you need to comply with the standard on duties of attendants. It covers the requirements for the attendant to be familiar with the hazards faced during entry (i.e., mode, signs and symptoms of exposure), behavioral effects of hazard exposure by entrants, maintaining accurate count of entrants, remaining outside entry, communication with entrants, assessing activities inside and outside space, when to summon rescue, taking action when unauthorized persona approach space, performance of non-entry rescue, and not performing any other duty other that attendant duty.  

You also need to comply with the standard on training which requires that all employees involved in confined space entry are properly trained (i.e., possesses the understanding, knowledge, and skills necessary for the safe performance of the duties), and that the employer ensures employee proficiency. All training records are to be maintained for the period of time the employee is employed by the employer. 

More information can be found on the A-Z safety and health topics page for confined spaces.

Are employees performing duties as an entry supervisor?

Are employees performing duties as an entry supervisor?

If yes, then you need to comply with the duties of entry supervisors standard. It provides the requirements for the entry supervisor to be familiar with the hazards faced during entry (i.e., mode, signs and symptoms of exposure), procedures for endorsing permits, terminating or suspending permits, verification of rescue services, removal of unauthorized individuals from permit space area, and ensuring that acceptable entry conditions are maintained. 

You also need to comply with the standard on training which requires that all employees involved in confined space entry are properly trained (i.e., possesses the understanding, knowledge, and skills necessary for the safe performance of the duties), and that the employer ensures employee proficiency. All training records are to be maintained for the period of time the employee is employed by the employer. 

More information can be found on the A-Z safety and health topics page for confined spaces.

Are employees performing rescue or emergency services for permit spaces?

Are employees performing rescue or emergency services for permit spaces?

If yes, then you need to comply with the standard on rescue and emergency services. It provides the requirements pertaining to evaluating a prospective rescuer's ability to respond to a rescue summons in a timely manner, proficiency in rescue-related tasks, properly trained in assigned rescue duties and has required equipment (i.e., personal protective equipment, annual training, first aid and CPR), rescue equipment (i.e., harness, retrieval line), safety data sheets, and requirements pertaining to non-entry rescue.

You also need to comply with the standard on training which requires that all employees involved in confined space entry are properly trained (i.e., possess the understanding, knowledge, and skills necessary for the safe performance of their duties), and that the employer ensures employee proficiency. All training records are to be maintained for the period of time the employee is employed by the employer. 

More information can be found on the A-Z safety and health topics pages for confined spacesmedical services and first aidpersonal protective equipmenthazard communication, and respiratory protection

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