Frequently Asked Questions Construction | Fire Service | Fixed Industry

Fixed Industry

Question: Confined Spaces

Our policy is to make all confined spaces "permit required". Better safe than sorry, right?


Confined Space

In the following example, classifying a confined space as a Permit-Required Confined Space and following all of the requirements for a Permit-Required Confined Space entry will not necessarily make an entry any more safe than entry under another classification.

Regulations require you to initially consider all confined spaces as Permit-Required Confined Spaces!  That is unless you have read and understand the Hundreds of OSHA CPLs and Letters of Interpretation!

Employers with Confined Spaces must realize that many regulators will not appreciate that classifying a confined space as a Permit-Required Confined Space and using Permit-Required Confined Space entry procedures will not always enhance worker safety in confined spaces.

Let’s review what a confined space is.  It is a space that has ALL of the following:

  • Is large enough and arranged so an employee could fully enter the space and work.
  • Has limited or restricted entry or exit. 
  • Is not primarily designed for human occupancy.  (OSHA language, “…for continuous employee occupancy”)

Now you review the following four (4) criteria to determine if the space is a Permit-Required Confined Space.

    • 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.

After answering these questions you will classify the confined space as one of the following three (3) classifications of confined spaces.

  1. Permit-Required Confined Spaces, these represent the most dangerous type of confined space because by their very definition the serious hazards have merely been controlled not eliminated.
  2. Alternate-Entry Confined Space, a confined space that only has an actual or potential atmospheric hazard that can be effectively controlled by continuous ventilation during entry.
  3. Non-Permit Confined Spaces, the safest confined spaces because all serious hazards have been eliminated prior to entry.

For reasons above many employers choose to use Non-Permit Confined Space entry procedures whenever possible.  Simply said, a Non-Permit Confined Space is the safest of all confined spaces. 

Now let me repeat, classifying a confined space as a Permit-Required Confined Space and following all of the requirements for a Permit-Required Confined Space entry will not necessarily make an entry any more safe than an entry under another classification.
For those of you in Water Utility work involving domestic water supply a common consideration is an engulfment (by water) potential.

If you determine that when engaged in line breaking, an engulfment hazard exists in a confined space, you must achieve ISOLATION i. e. hazard elimination, if you want to classify the confined space as a Non-Permit Confined Space.  Isolation by definition means (blanking or blinding; misaligning or removing sections of lines, pipes, or ducts; a double block and bleed system; lockout or tagout of all sources of energy).

Most all water transmission or distribution systems will not be able to isolate the line breaking operation without significant impact to other customers and including fire suppression.

Water Utility workers should be aware that a confined spaces, in-which line breaking occurs AND an engulfment hazard exists, can not be classified as anything but a Permit-Required Confined Space.

Why is this important?

If your evaluation determines that the confined space is a Permit Required Confined Space because of the engulfment hazard you must use either:

  •  A Non-Entry Retrieval System or
  • An Entry rescue Provider

In this example you have a confined space configuration and/or job tasks where entanglement hazards exist or will be created; therefore, you make a determination that Non-Entry Retrieval Systems are not feasible.

You are stuck with the single most dangerous type of confined space entry.  A Permit-Required Confined Space requiring Entry Rescue and an Entry Rescue Provider.

Is your operation capable of fielding its own rescue team?  Is the local Fire Department?

During the past year, I have had opportunity to evaluate multiple confined spaces where this very issue exists. The confined space has an engulfment potential, double block and bleed (double valving) is not possible and even it were, the water system does not typically have drain capability between valves.  Lastly, there are entanglement issues for workers wearing and/or connected to a Non-Entry Retrieval System.
In each situation, I would recommend if it were not in violation of the regulations, a hybrid Non-Permit Confined Space procedure that emphasized second upstream and down stream valve checks and maintaining immediate valve access. 

The H&S Compliance Issue:

As I stated, if you were to classify this example as anything but a Permit-Required Confined Space you would be violating the Regulations.

If on the other hand you classified it as a Permit-Required Confined Space what greater protection have you provided to the entrants?  In the event of a catastrophic incident, the entrants are going to make egress or the rescue provider is going to tell you "turn-off the water, then pump the water out of the confined space and we will perform recovery."

This is not some unique scenario but is an issue for employers all over Washington as well as the entire USA.  

At this time this issue can be most effectively addressed by application for a variance.  The variance will in all likelihood be denied but the employer would have a reasonable defense of a greater hazard being created by complying with the regulation.
Refer to the OSHA Interpretation below.  Pay particular attention to the fourth paragraph from the end of the letter and the phrase “…definition of the term "isolation" must be used in order for the hazard to be considered eliminated.”
OSHA Interpretive Letter specific to double valving to achieve hazard elimination and allowing “Non-Permit” Confined Space classification, (title 1995 - 08/28/1995 - The Lockout/Tagout Standard)

This specific issue has come to attention of others and is being addressed most proactively in British Columbia.  For more information see: Work Safe BC Confined Space Regulations specific to “Public Water Supply System” 9.18.1 Exemptions at the following location


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