The Confined Space Permit to Work

Construction and maintenance activities in industrial environments can often involve work in confined spaces. A confined space incident can be sudden and lead to multiple fatalities. People vastly underestimate their ability to enter a restricted area or an oxygen-depleted environment to rescue a fallen co-worker, sometimes with tragic consequences.  Simply putting your head into an oxygen-depleted atmosphere (for example by looking into a nitrogen-filled tank through a manhole) can result in loss of consciousness in as little as 15 – 20 seconds followed by death in 2-4 minutes.

Owing to the elevated risk relating to confined space entry a set of best practices and standards have evolved.  For example, the OSHA standards in the USA include a specific provision for confined space work.    [US Department of Labor Occupational Safety and Health Administration OSHA 29 CFR 1910.146, “Permit-required Confined Spaces“].

Similar standards apply in most countries and might also be industry specific. Another example is In Australia where the WHS Act and Regulations govern confined spaces. The Confined Spaces Code of Practice published by Safe Work Australia is approved in several jurisdictions.

Standards serve to guide people in the correct design, safeguarding and maintenance of equipment where confined spaces are involved.  During plant design, for example, the principle is to eliminate any required confined space work in the first place, but of course, this is not always practical.

The “confined space permit” is specifically developed to cater for the additional precautions necessary for working in these dangerous situations.

The criteria for deciding if a confined space permit is needed in specific circumstances is the subject of a separate article.   There are specific techniques that can be used to properly identify confined spaces on the plant, and there are consultants that specialize in assisting you in this identification process to develop a  detailed confined space register for your site.     What is important is to err on the side of caution and to always prioritise the safety of the people doing the work.  Your own specific circumstances should always be considered and you should view the law as the minimum standard to be maintained when developing your confined space procedures.

In this article, we will cover the basic principles around working safely in confined spaces.  We will then look at the confined space permit with some specific examples of how the IntelliPERMIT system supports this process.

What is a confined space?

Confined spaces occur in several scenarios in mining, process manufacturing, construction industries and so on.

  • The most obvious example is a large vessel or tank that is designed to hold liquid or gas and which needs to be opened for inspection and maintenance.
  • Another example, this time from the brewing industry, is the large automated pasteurizing machine on the bottling lines.  This machine is enclosed and uses hot steam as a source of heat.  The pasteurizing machine has several internal moving parts and will need to be shut down and cooled from time to time so that maintenance can take place to remove any broken glass etc.
  • A third example might be an enclosed tunnel or pit below ground level through which piping and cables run.

OHSA defines a confined space as having three characteristics:   Size, Design and Access:

Definition of a confined space (OHSA)

When people do enter confined spaces, there can be a risk of entrapment, asphyxiation or exposure to chemicals.  Further, there may be abnormal temperatures, moving machinery or sources of energy such as a live electrical system.  Other situations might involve unsecured items (like a vessel lining or caked solids on the roof of a coal-fired boiler).  These solids might dislodge or fall from above onto workers in the space below.

Entering confined spaces for any reason is very dangerous and the legislation will normally require that a permit to work be issued for all work taking place in this space.   Even in circumstances where legislation is not prescriptive, the duty of care will apply and employers will need to take the necessary precautions to avoid harm.

Confined spaces need to be clearly identified and their locations and any specific hazards need to be made known to all people working in that area.   Danger signs need to be clearly visible and suitable measures such as barriers or fences need to be in place to prevent anyone not authorized from entering these spaces.

When designing the plant, any confined space entry needs to first be avoided by first considering alternatives.   These might include easy disassembly of equipment for improved access, allowing for decoupling and removing machinery out of enclosed units, allowing adequate space for easy entry and exit from vessels, special tools, including a second access point to avoid the risk of entrapment and so on.

Having identified the confined spaces on the plant, the employer will also need to create a written procedure for confined space entry.  This procedure needs to be made available to those doing the work and should be in simple language to be understood by everyone involved.   Training is one way to make sure that these procedures are properly followed and this can be done as part of the site induction program for contractors, or as part of a structured training program for permanent employees.

The confined space entry procedure needs to accommodate the following steps:

  1. As far as possible, prevention and avoidance of any task that will involve confined space work.
  2. Preparations to make the enclosed space safe (for example by isolating energy sources, purging with air, maintaining oxygen levels, testing for toxic or explosive gases).
  3. Informing persons involved in the work on their roles and responsibilities and making sure they are competent for their specific role.
  4. Creation and regular review of a confined space register including relevant rescue plans and drawing.
  5. Provide all necessary protective, extraction/retrieval and environmental monitoring equipment.
  6. Ensuring that emergency services are available and the procedures are in place and understood for rapidly mobilizing assistance if required.
  7. Issue and manage the confined space permit in line with the companies written procedures.
  8. Monitor the work taking place for additional hazards, adjacent work, changes in the environment/conditions and the progress/signs of physical and mental exhaustion of the people involved.
  9. Testing that work has been done satisfactorily and that these tests are also done under safe conditions.
  10. Proper restoration of the site after work has been completed for the resumption of normal operations.

In addition to the list above it is typical that the company reviews any confined space work on a regular basis (for example annually) with the view to avoiding such work as far as possible and improving the written procedures where necessary.  This involves regular planned audits of adherence to procedures in the permit system and incorporating any learning into the rules for safe work.

The confined space permit

The confined space permit is an important document that brings all the information regarding the risks, preventative measures and precautions to the attention of the people doing the work.     IntelliPERMIT supports the confined space permit process in many unique and important ways:

Visibility of confined space work

All current confined space permits can be highlighted in the various displays in the permit office or control room.  For example, they can be highlighted on the plant layout area display showing the location of any work taking place in confined spaces in relation to adjacent work in the same area.

The visibility of confined space permits can be further enhanced by colour coding the permits and the physical documents.

Prior identification of confined spaces in a register and enforcing special rules

Equipment associated with confined spaces can be set up in the IntelliPERMIT database so that work in these items can automatically flag the permit requester that a confined space permit is required.

Having identified the correct equipment, the system will also prompt the operator with the appropriate standard isolations for the confined space. IntelliPERMIT can incorporate marked up P&IDs and other schematics to assist the isolation coordinators incorrectly following the isolation instructions.

Specific elevated risks for long-running equipment

Entry into confined spaces may involve elevated levels of risk depending on the state of the equipment.  For example, the risk of a ball mill liner detaching increases over time, depending on the throughput of the mill – making vessel entry very dangerous.  IntelliPERMIT has been used to gather data from plant instrumentation and control systems to flag these situations and implement rules for scheduled inspections by experienced personnel prior to confined space work commencing.

Ensuring work is done by competent people trained in the task

It is critical that both the workers in the confined space and the spotter observing the work are properly trained, assessed as competent and authorised for the work.

IntelliPERMIT’s confined space permit is authorised electronically and will help ensure that each person involved in the work has been recently trained and assessed, and is deemed competent for their role.

The role of the spotter

A qualified spotter (sometimes referred to as the “Attendant” or “Stand-by”) is usually required to monitor confined space work at the work site.  The spotter is positioned in a safe location outside the permit space.   The spotter is there to call for assistance and emergency services in the event that there is a problem and not get involved directly in early rescue efforts.     The spotter can have other responsibilities in terms of communicating, monitoring and controlling entrants to the confined space in line with the company’s procedures.

The spotter is normally provided with a comprehensive rescue plan and needs to be familiar with this plan before the permit is authorized.

The spotter also needs to sign the permit accepting their responsibilities and understanding that their full attention is required for the duration of the task.  IntelliPERMIT can be configured to prevent the spotter from accepting any other permit-related responsibilities while the confined space work is in progress.  For example, they may not sign on as a spotter for any other confined space work happening concurrently.

Only once the job is complete, and all people are out of the confined space and have signed off the permit, is the spotter allowed to sign off.  Should the spotter need to be relieved, another suitably competent person may sign to take over the responsibility and release the original spotter

Gas testing in confined spaces

Gas testing is required before any person enters a confined space, and should be continued during the job if there is any risk of oxygen levels being depleted over time or any chance of toxic gases being introduced (example fumes from welding).

Continuous or forced ventilation may also be required to keep the job site safe during the work.

The required gas tests can be linked to specific hazards identified during the preparation of the permit, or at the job site during the risk assessment.

Gas testing should be carried out by suitably qualified persons.   IntelliPERMIT can check the individuals training records and their competency status before they can be assigned to perform this role.

Testers must also use gas testing devices that have been properly calibrated and within the mandatory service intervals – the list of devices and the calibration schedule can be managed by IntelliPERMIT.

Continuous Ventilation

An example of continuous ventilation into a confined space

Emergency response crews

It is important that emergency response personnel are aware of all confined space jobs that are scheduled to take place.  A representative may be required to also sign the permit before it can be issued.  A constantly refreshed list of confined space jobs under preparation or execution can also be displayed in the emergency response crew’s offices.

Workgroup interactions

IntelliPERMIT identifies the potential for elevated risk relating to workgroup interaction in and around confined spaces.   It does so through visual displays of planned and current activities; the enforcement of specific rules prior to the issuing of permits that may impact other crews already in the field, and maintaining an audit trail of communication between the various crews.

Workgroup interaction rules can include the requirement for the supervisors of each work party to both provide their credentials and sign on a single screen within a limited timeframe (analogous to two independent persons turning their own keys to launch a missile).  This makes sure that both working parties are fully aware of the activities of the other group.


Confined space entry is a particularly dangerous activity and special care needs to be taken when work is done.  The confined space permit assists the employer to make sure that adequate precautions are in place for each job or task involving confined spaces.

Best practices for confined space entry have evolved into legislation and need to be incorporated into the company’s formal documented procedures for confined space entry.  This is both a legal requirement as well the duty of care.

IntelliPERMIT fully supports the confined space permit to work process and has been used in many jobs to ensure that the processes are followed and the people are informed, and competent to do the work.  Together with our partners, the team at Adapt IT can assist with auditing the site to develop and update the confined space register, auditing confined space procedures and recommending improvements, assessing the skills and following through with training interventions and more.   These all lead to a successful implementation of a confined space permitting system.


Safe Work Australia Code of Practice – Confined Spaces

United States Department of Labor – Permit-Required Confined Spaces

For more information on confined space permits and what auditing services our partners offer in this regard please contact the IntelliPERMIT team at Adapt IT.

A Confined Space Is:

  • Large enough for an employee to enter fully to perform assigned work.
  • Not designed for continuous occupation.
  • Has limited or restricted means of entry or exit


Picture of Eugene Lategan
Eugene Lategan
With 13 years of OpSUITE consulting across energy, mining, manufacturing, oil, and gas industries in Africa, Asia Pacific, and GCC countries, Eugene is solution-driven, optimising and improving efficiency in Permit-to-Work and other operations.

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