The Confined Space Regulations ... Explained

It is a common misconception that the confined space regulations say you must use a gas detector, an escape set, fall arrest system, top man, rescue team etc. etc.  In truth they are simply not that prescriptive.  Like many other sets of regulations, once you have implemented a hierarchy of control, everything else is based on your assessment of the risks.

In this article we try to dispel some of the myths about the confined space regulations and give you a summary of exactly what is required.

The confined space regulations came into force in 1997 and whilst the main text (and requirements) of the regulations have not changed since then, the ACOP, and guidance, forming the document, "Safe Work in Confined Spaces," were revised in 2009 and 2014.  The latest (2014) edition of this document (also referred to as L101) can be downloaded free of charge from the HSE website.

Broadly speaking ...

The main regulations to bare in mind are:

  • Regulation 1 - The definition of a confined space
  • Regulation 4, Part 1 - Preventing the need for entry
  • Regulation 4, Part 2 - Safe working in confined spaces
  • Regulation 5 - Emergency arrangements

The ACOP (Approved Code of Practice) gives practical advice on how to comply with the regulations.  If you follow the advice, then you will be compliant.  The ACOP has a quasi legal status.

The guidance is not compulsory, but if you do follow the guidance you will normally be doing enough to comply with the regulations.

Regulation 1 - Definition of a confined space

First you must determine whether your entry will be classified as a confined space.

Regulation 1 gives the definition of a confined space and plenty of guidance on how to apply that definition.

A confined space can be anywhere that is enclosed (or partially enclosed) and where it is reasonably foreseeable that one or more of the following specified risks may occur:

  1. serious injury from fire or explosion,
  2. loss of consciousness from increase in body temperature,
  3. loss of consciousness or asphyxiation from gas fume or vapour,
  4. loss of consciousness or asphyxiation from lack of oxygen,
  5. drowning from increase in level of liquid,
  6. asphyxiation from free flowing solid,
  7. entrapment from free flowing solid.

You should note that we are looking, for example, at whether a person will lose consciousness from a gas fume or vapour, not just whether a gas fume or vapour may be present.  Toxic gases exist in the air that we breathe in our homes, workplaces and outdoors, but they are not usually present in sufficient quantities to harm us.  Where it is reasonably foreseeable that a toxic gas may be present in a sufficient concentration to cause loss of consciousness then the confined space regulations may apply.  The same logic should be applied to the other specified risks stated above too.

Do not just consider the space/structure itself - make sure you consider the inherent (already present) hazards and the hazards introduced by the task you are carrying out.

For more information on how to define a confined space, see our blog, "Confined Space Definition - Explained."

Regulation 4, Part 1 - Preventing the need for entry

It is a legal requirement for you to prevent the need to enter a confined space by either modifying the space, the task or the process, if it is reasonably practicable to do so.

For example if you can use long handled tools, in-situ cleaning systems, CCTV cameras or some other means to prevent the need to enter, then you should do so.

You are allowed to consider the time it may take to implement these controls,  the cost of implementation and the difficulty with which they can be implemented and balance this against the level of risk.  This is what is meant by reasonably practicable and a good explanation of this and other similar terms can be found on the HSE website.

You should record that you have considered whether you can prevent the need to enter a space.  Often this assessment is carried out and small measures are taken to prevent entries, or reduce the frequency of entries but this is seldom recorded.  I suggest recording the thought processes or actions that have been taken at the beginning of the safe system of work.

Regulation 4, Part 2 - Safe working in confined spaces

Once you have determined whether your entry is defined as a confined space and whether or not it is reasonably practical to achieve your task without entering the space, then you should establish a safe system of work.  This should be produced by a competent person (or persons), documented and communicated to all interested parties.

The safe system of work should include:

  • A risk assessment documenting all foreseeable hazards, the risks associated with these hazards and the precautions to be taken to eliminate or reduce these risks.  Further guidance on risk assessment can be found on the HSE website.
  • A safety method statement or operating procedure detailing the precautions to be taken in the correct sequence.  There is a long list of items in L101 that should be considered, including, testing the atmosphere, competency, isolations, access and egress and static electricity, and guidance on what to consider for each item.
  • A permit to work.  A permit is unlikely to be needed where risks can be easily controlled, the work is simple, and where other activities will not affect safe working.  A permit is not a legal requirement, however it is often used and is useful:
    • to ensure the hazards, precautions, nature and extent or work is communicated to all interested parties,
    • as a checklist to ensure that all elements of the safe system of work are present,
    • to control isolations and other pre-entry preparations,
    • to co-ordinate (or exclude) other works that may affect the confined space entry, or
    • to confirm authorisation to carry out the confined space entry.

Regulation 5 - Emergency arrangements

Regulation 5 is the regulation most often misunderstood (and dare I say it) the regulation that unscrupulous providers often mis-quote.

Regulation 5 requires that no-one should enter or work in a confined space unless there are emergency arrangements in place that are appropriate to the level of risk.  These emergency arrangements should include making provision for extracting workers from the confined space and making provision for first aid (including resuscitation equipment) where required.

This section also highlights the need to protect those who may implement the emergency arrangements,

".....the arrangements shall not be suitable and sufficient unless -

  1. they reduce, so far as is reasonably practicable, the risks to health and safety of any person required to put the arrangements for rescue into operation;....."

Emergency arrangements may include self rescue, non-entry rescue and/or the use of an on-site standby emergency rescue team.  These terms are explained in our blog, 'Confined Space Rescue - Is it a Legal Requirement?'. 

The emergency arrangements should be produced by a competent person (or persons), documented and communicated to all interested parties.  Any person involved in rescue should have the necessary physical and mental competencies to carry out the rescue and be properly equipped.  Remember - the safety of the rescue team is just as important as the safety of the entrants and your duty of care extends to the rescue team.

In summary

  • Define your confined space entries.
  • Prevent the need to enter confined spaces where reasonably practicable.
  • If you have to enter, follow a safe system of work.
  • Ensure you have suitable emergency arrangements in place.

Work out which of the tasks you carry out involve entering (or other wise affecting) a confined space.  It is a good idea to document these, perhaps in a confined space register, or other similar format.

Once you have determined which of your tasks involve confined space entry, look at whether you can prevent the need to enter the spaces.  This may involve adapted tools, a change to the process, or another method that achieves the task without the need to enter the space.  At the very least you may be able to reduce the frequency of the entry or reduce the number of people required to enter the space safely.

If you still have to enter the space then the entry should be carried out in accordance with a written safe system of work.

Arrangements should be made to recover a casualty in the event of an emergency.  These emergency arrangements should be suitable and sufficient and should include provision for safeguarding rescuers.

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CSTS provide dedicated, full time confined space support and rescue teams and a confined space advisory service.  Click here for more information on the services we offer, give us a call on 01925 244144 or email us on