Permit Required Confined Space vs. Non-Permit Required: What are the differences?

Confined Space TrainingIn talking with customers every day, I’ve come to realize there is some confusion out there as to the various different aspects of a confined space and the rights and responsibilities of those working in or around them.  Over the coming weeks, we’re going to do a series of summary posts in an effort to help clarify this topic a little.

In this post, we’ll talk about the 2 main types of confined spaces – permit and non-permit required – and their differences. But before we talk about that, let’s first establish what a confined space is, shall we?

OSHA defines a confined space as being made up of 3 main parts: 1) being large enough for an employee to enter and perform work; 2) has limited or restricted means for entry or exit; and 3) is not designed for continuous occupancy.  This describes many kinds of areas a worker can come in contact with on a daily basis.  And it also illustrates what would be considered a non-permit required confined space.

Now, a permit required confined space will contain all of the above, plus one or more of the following:

  • a substance that has the ability to engulf or asphixiate the entrant
  • a potentially hazardous atmosphere
  • inwardly converging walls within the space or a floor the slopes downward, tapering to a small cross-section
  • contains any other serious safety or health hazard

Once a confined space has been identified as having any one of the above four potential hazards, an employer should identify it as such via either signs or another effective means of communication.  Any time an employer has workers that will be entering confined spaces, there needs to be a written program developed that outlines and instructs on the proper procedures for working around these spaces.

One such important procedure is drafting the actual permit for the permit required confined space.  This is called the entry permit and is defined by OSHA as:

the written or printed document that is provided by the employer to allow and control entry into a permit space and that contains the necessary information as required in paragraph (f) of this standard’s section.

I can hear you now…just dying to find out what is in paragraph f!  Well don’t get too excited, because OSHA lists 14 required pieces of information that need to be onEntry Permit Sign an entry permit.  And in the spirit of resourcefulness, I’ll list each one here, but thought it might also be helpful to show an example of a typical entry permit, with all of the correct information, so I’ve included that after the list. And without further ado, the information OSHA wants to see on an entry permit:

(1) The space to be entered;

(2) The purpose of entry;

(3) The date and authorized duration of the permit;

(4) The authorized entrants within the permit space, by name or some other means that will enable the attendant to determine quickly and accurately, for the duration of the permit, which authorized entrants are inside the permit space;

(5) Names of attendants;

(6) Supervisor’s name, with a space for the signature or initials of the supervisor who originally authorized entry;

(7) The hazards of the space to be entered;

(8) The measures used to isolate the permit space and to eliminate or control any hazards before entry (i.e. purging, flushing, or ventilating the space as well as lockout and tagging of equipment);

(9) Acceptable entry conditions;

(10) The results of any initial and periodic tests performed, 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 called on and the means (such as the equipment to use and the numbers to call) for reaching 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 used;

(14) Any other information whose inclusion is necessary, given the circumstances of the particular confined space, in order to ensure employee safety; and any additional permits, such as for hot work, that have been issued to authorize work in the permit space.

Confined Space Supervisor

Confined Space Competent Person

So as you can see, the differences between the two types of confined spaces is quite large, and important to know.  Confined Space work is one of the leading causes for occupational fatalities in the U.S.  A big part of that comes from workers not being properly prepared for, or even having knowledge of, the potential hazards that can be lurking within a space.

Knowing the difference between a permit and non-permit required space will help prepare you for those hazards by knowing when proper safeguarding measures need to be taken.  If you’d like to know more about this topic, and be properly certified in this area, we offer a Confined Space Supervisor and an Awareness Level course.  Or add this blog to your RSS Reader, as we will be covering more on this topic in upcoming posts!

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  • John Zalas

    What I’m trying to understand are the rules/regulations that would be applicable to a non-permit required space. Is the determination of safety requirements up to the, owner of the space, employer, or the employee entering the space? Is there a general guidline for non-permited spaces above and beyond personal experience?

    • niall

      John, a non-permit required confined space is a standard space, such as a utility vault, which has the same characteristics from vault to vault. The regulation requires the employer to establish a verifiable safety practice which guarantee the space is free of hazards.

      For example, to ensure a vault is free of hazards, one procedure is to ensure lockout tagout of electrical sources and to use positive ventilation (blower fan) to introduce fresh air into the vault. The non-permit confined space entry form would be completed indicating these procedures were to be performed prior to entry of personnel into the space.

      This procedure would be available for review by OSHA, however a permit form would not be required for each entry. If conditions change, the verification process would have to be performed before entry of personnel. This procedure was designed for electric companies, gas companies, and similar situations where standard confined spaces were entered frequently.

      Hope this helps. Let us know any other questions!

      • Steven Shantz

        I’m a bit confused by your answer. Are you saying that a Confined Space procedure is required even for facilities that do not Permit-required confined spaces? And you seem to indicate that an entry form is required. Also, what are the training requirements for facilities that do not have permit required confined spaces?
        Finally, regarding what constitutes ‘any other serious health or safety hazard’…
        What about a vault containing a shut off valve or meter for water?
        What about a vault containing steam pipes, or steam pipes and a steam trap?
        Do any of these conditions move the vault up to the permit required status, or can such a vault be entered without a formal permit if the services are shut off? What if they are not shut off?

        • niall

          That’s right Steven, because you need to have a procedure in place to identify whether a confined space is permit-required or not in the first place.

          There are no additional training requirements for facilities that do not have permit-required confined spaces, as these spaces would have been deemed to have no potential hazards.

          Much of what you described regarding the vault containing either a shut off valve, steam pipes, or water meter is very situational and depends heavily on what the individual set up of that particular space is. Where is the vault or meter located? If it is located on the inside of the space, then there is a hazard present, because a worker would have to enter the space before shutting it off, exposing him/her to a potentially hazardous situation.

          Even if it the meter or shut off is located outside the space, there could still be residual energy left in the system that may create a hazardous condition within the space. To be safe, in your example, erring on the side of caution and deeming that set up to be permit required would be recommended. But not knowing the exact set up you are working in makes it difficult to diagnose, which is why it is up to the owner/employer to make the determination.

        • Randy Harmer

          I am having issue with a current situation I am a new hire of a company who enter railroad tank cars they are free from hazards as they test the environment steam and wash them prior to entry but the sides slope and they are classifying this as non-permit required. Being new to this company I shook my head because of the osha standard but would like to hear opinions the inside of the tank is round and cylindrical in shape and have only one exit which they are placing a ladder in the entry to enter and exit, I am with the opinion it is permit required.

  • After reading this post I came to know the difference between permit required confined spaces and non-permit required at first I was not very clear about these two but now I know the difference and I would really appreciate your post. Thanks for sharing it and giving us complete knowledge on this issue.

  • natem

    What about a vault that would be non permit but then a task such as waterproofing needs to be completed inside. Waterproofing often has toxic fumes which could then cause a hazardous atmosphere. Is this space still non permit?

  • I had a NAVFAC Engineering Technician tell me today that it does not matter if you have a permit or non permit confined space you still need to be tied off to retrieval and have an attendent.I am clear on the fact that you do not have to fill out a permit if you are able to classify the confined space as a non permit space, but what about retrieval and attendants. I can not find anything that says, because you have a non permit confined space, workers in the non permit confined space are therefore not required to be tied off to retrieval and an attendent is not required.

    • niall

      Hi Dave, thanks for reading! A “non-permit required confined space” requires all the safety requirements that a “permit required confined space” requires unless
      these can be avoided by using engineering such as ventilation to eliminate the hazard.

      As long as the procedures, such as using ventilation, are used for each entry, no permit is required. Many companies, utilities, and organizations choose to have the same requirements for “permit-required” and “non-permit required confined
      spaces” for liability purposes. This is based on 29 CFR 1910.146.

      NAVFAC may have procedures which require all confined spaces that have a potential hazard be treated as a “permit-required” confined space regardless of engineering controls. Let us know if you still have questions.

    • Steve Johnston


      I know this is old, but like many NAVFAC ETs, yours was apparently smoking crack. By OSHA and EM-385 definition, a confined space ATTENDANT is an individual who is stationed outside a PERMIT-REQUIRED confined space. Hence, by definition, an attendant is not applicable to non-permit spaces

  • How about Attic Space and Crawlspace (residential homes) based on OSHA Definition this would be non-permited but you still have to have procedure in place to identify whether a confined space is permit-required or not in the first place. Is this a once a year document or a site specific doc (each job site) to prove that it is non-permited? In Case OSHA audits your records or does a site visit during your project. Also is there a minimun awareness training required by OSHA for employees that may have to enter this type of confined space again for Attic Space or Crawlspace in residential homes. Thanks Gio

    • niall

      Hi Gio, an attic space or crawl space is not an OSHA permit confined space unless there is a potential hazard from airborne contaminants such as oxygen deficiencies or toxic levels, flammable levels, or a configuration hazard. The option of a non-permit confined space was originally for utilies for entering similar vaults and manholes. The rule requires the requester to define the configuration and the
      methodology (such as ventilation) that will make the space safe. As long as the methodology is followed, no permit is needed. The methodology must be documented.

      We offer a minimum awareness level Confined Space course ( which will cover what OSHA wants entrants to know, as well as a Supervisor Confined Space course (, which offers a more in-depth level of training.

      A supervisor will need to prepare a written confined space program to define the policies and procedures and methodology for entering confined spaces. This is explained in the supervisor class. Also the supervisor must determine if the confined spaces are permit-required confined spaces.

  • Chris

    How about an industrial garbage compactor ? The compactor has a garage door to block of the entrance and is left open while employee goes to dump the cardboard boxes in. There is also a gate that seperates the employee from the compacting area. How would you approach this? In reality it is a confined space; however, has engineered controls to prevent the employee from falling down into the compacting area (not a large drop). Also, the compactor is not on when the employee enters and is operated from outside the door when the trash is ready to be compacted.

    • niall

      Hi Chris,

      As long as the space has the engineering controls in place and there are no other hazards, and without more specific details, it would not seem to meet the permit-required definition.

  • john

    what if you dont need to enter vessel or structure but just break the plane? do you still need a permit?

    • niall

      Hi John,

      A permit is required if an exposure at the entrance of a confined space puts the person at risk. For example, if the space is being purged with nitrogen gas and the person becomes asphyxiated, even though they were not in the space, OSHA considers that a necessary inclusion into the Permit Required Confined Space requirements.

  • grant

    My question is, I have a excavation that is 20foot by 20 foot 8 or so feet deep they started out calling it a permitted confine space then changed it to non permitted confined space…is this a permitted confined space or not?

    • niall


      For an excavation like this, if it is 8 feet deep, I am going to assume that there is limited access to the trench, perhaps only via a ladder. Because of its limited access, our recommendation would be to err on the side of caution and classify this as a permit-required confine space and to monitor any entrant activity closely, as well as ensure the proper safeguards for an excavation of this size and soil type are taken.

  • Palani

    A very good article. I have a current issue.
    As per the entry procedures of some companies gas testing shall be repeated if the space remains unoccupied for more than 30 minutes. Is this true as per OSHA or any other standard?

  • Operator Staterbros

    We have to enter a confined space that has no problem oxygen deficency to change belts on equipment.
    The condenser tube bundels do contain anhydrus ammonia below the space. What type of a permit would this be considered?

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