OSHA Confined Space Standards for the Construction Industry

While OSHA’s confined space standards have been on the books since 1913, it wasn’t until 2015 that the Administration issued such rules specifically for the construction industry. Construction workers encounter many risks you won’t find in other industries, particularly when workers enter tight, limited or restricted spaces.
29 CFR 1926 subpart AA.

Here’s what employers within the construction industry need to know about the newer set of OSHA standards required for working in confined spaces:

What is a Confined Space According to OSHA Guidelines?

Like it or not, OSHA standards are part of the Code of Federal Regulations. That means they’re fully enforceable by the agencies that propagate them. In other words, compliance is not an option.

Because of this legal force, the framers of the regulations define their terms very carefully. Without a full understanding of the letter of the rule, it can be hard to comply with OSHA’s standards on confined spaces in the construction industry. To be clear, then, there are three criteria an area must meet in order to be defined as a “confined space” for OSHA’s purposes under 29 CFR 1926 subpart AA:

  • Entry and exit into the space has some restriction, such as limited size or difficult access.
  • The space is large enough for a human to enter.
  • Planners never intended the space for “regular” or “continuous” occupancy.

That’s it. So what kind of spaces at a construction site might we be talking about? A note to standard 1926.1201(a) lists examples, including, in alphabetical order, the following:

  • Air Receivers
  • Bag Houses, Bins, and Boilers
  • Cesspools and Chillers
  • Digesters and Drilled Shafts
  • Enclosed Beams
  • HVAC Ducting
  • Incinerators
  • Lift Stations
  • Manholes and Mixers
  • Pier Columns and Pits
  • Reactors
  • Scrubbers, Sewers, Silos, Sludge Gates, and Storm Drains
  • Tanks and Transformer Vaults
  • Vessels
  • Water Mains

However, OSHA doesn’t designate just one type of confined space. It places restrictions on use of two different classes of these areas: typical confined spaces, as defined above, and a special class called permit-required confined spaces or, more frequently, a permit space. Most of the rules within standard 1926 subpart AA concern these permit spaces, so it’s important to understand exactly how they’re defined.

What is a Permit-Required Confined Space Under OSHA Standard 1926 Subpart AA?

As the name implies, in order to enter the more restrictive type of tight area, workers must obtain a permit from an entry supervisor, complete with a time limit on allowed entry. Employers can’t hand out permits until they meet strict safety requirements, including the preparation of a written permit-required confined space program.

First things first. A permit space meets all the criteria of a confined space, as outlined above, as well as any of the following:

  • The presence of a hazardous atmosphere, or the potential for the air to become hazardous.
  • A risk of flooding or entirely engulfing workers in some material.
  • Hazardous shape that could trap or asphyxiate a person.
  • Any other recognized danger or health risk.

The core of subpart AA of standard 1926 lies in its safety requirements for permit spaces. Those requirements, by turn, are reflected in the permit-required confined space program (simplified as a “permit space program”) as outlined in standard number 1926.1204.

(Read the original text of the standard here.)

Responsibilities of Multiple Employers on Construction Sites with Permit Spaces

Construction jobs are unique in OSHA’s eyes in that they typically involve multiple employers. In order to understand the requirements of a permit space program, you must define these unique roles. Regulators identify three types of employers on a construction site, each of whom may carry a different responsibility within the permit space program. Business owners on a construction job may be one of the following:

  1. The host employer

    owns or manages the work site property. People in this role may have existing information about confined spaces and permit spaces in the area, and they have a responsibility to share what they know on the subject with the controlling contractor.

  2. The controlling contractor

    carries the most responsibility of anyone in these three roles. This employer must oversee all entry into permit spaces, even when the site features multiple entry employers.

  3. Entry employers

    are the ones who make the call on sending workers into permit spaces. There might be multiple entry employers, since multiple contractors usually work on a single construction site. Entry employers are bound by all the rules within subpart AA of standard 1926.

Entry employers on construction sites must start with a list of confined spaces at the work site and determine which ones, if any, require permits. A “competent person” has to be in charge of this task. Note, also, that both host employers and controlling contractors must share any knowledge they have about permit spaces on the site.

(Before the jokes about what constitutes a “competent person” start, here’s the definition in the OSHA standard: “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.”)

Requirements of a Permit-Required Confined Space Program

The regulations list a series of safety goals that employers must meet in order to allow workers into permit spaces. Solutions comprise the permit space program; they must all be written out and provided to permitted employees and the controlling contractor. The entry employer’s responsibilities according to OSHA standard 1926.1204 include the following:

  • The entry employer must “implement the measures necessary to prevent unauthorized entry.” That means keeping out everyone unless they have a permit.
  • Permit spaces, by definition, contain hazards. Entry employers must be aware of those hazards and make sure they’re taken care of before an employee enters the space.
  • That means entry employers must create and execute “means, procedures, and practices” that will keep authorized entrants to permit spaces safe. This is a broad topic, but usually includes things like identifying conditions safe enough to enter; installing ventilation/flushing equipment; placing barriers on entry; and consistent measuring of conditions while someone’s working inside.
  • Entry employers must also provide safety equipment including means to test and ventilate permit spaces. They must also provide personal protective equipment, sufficient lighting, and communications gear. Other required equipment includes barriers, ladders, and anything else it takes to make getting into and out of these spaces safe. In addition to providing the equipment, employers must ensure that employees use it properly.
  • In order to ensure safe entry into permit spaces, employees must be able to test conditions both before and after ventilation or flushing. It’s the employers responsibility to make sure these tests are completed, and that spaces are monitored at all times someone’s inside.
  • At least one attendant must be posted outside the permit space while others enter. If a single attendant has to monitor more than one space, the employer must create “means and procedures” for that employee to take care of problems in one space without abandoning another; in other words, it’s best to assign one attendant to each permit space.
  • Safety in confined spaces requires multiple well-defined roles. For instance, one worker will enter the space while another monitors the air quality, and a third supervises the location. Employers must clearly identify who’s in charge of what and make sure they’re trained for the job.

In addition to these specific requirements, entry employers need to create systems for calling rescue services, handling permits, coordinating with controlling contractors and other entry employers, and sealing the site after an authorized entry.

After employers write up all of these rules and procedures into a comprehensive permit space plan, they must review the program and revise at least every year, or when new hazards arise.

Of course, there’s much more to OSHA’s confined space standards for the construction industry, but this overview should be enough to start the conversation about how to protect workers. Learn more on OSHA’s resources page for confined spaces in construction.


29 CFR 1926 Subpart AA – Confined Spaces in Construction.OSHA. Occupational Safety and Health Administration, U.S. Department of Labor, n.d. Web. 28 Dec. 2018.  

Confined Spaces in Construction.OSHA. Occupational Safety and Health Administration, U.S. Department of Labor, n.d. Web. 28 Dec. 2018.

Irwin, Chris and Jessica Smith. “OSHA’s New Confined Space Standard.OHSOnline. 1105 Media, 1 Jul. 2015. Web. 28 Dec. 2018.

Protecting Construction Workers in Confined Spaces: Small Entity Compliance Guide.OSHA. Occupational Safety and Health Administration, U.S. Department of Labor, 2015. PDF. 2 Jan. 2019.

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