There have always been people prepared to enter confined spaces. But entering competently versus just throwing yourself into a situation are two very different matters. In his article, Andrew Watson delves into the requirements of the confined space regulations and the importance of understanding their application.

From a work (and regulation) point of view, the volume of work carried out in a confined space is limited. The regulations were introduced in 1997 due to the number of fatalities and injuries taking place within this limited number of confined space entries.

We have had the confined space regulations in place for 21 years. You would assume that after this considerable period of time the amount of training and rescue provided by cover companies would be seeing a decline in this area of business, but in reality nothing could be further from the truth. Training is up, and rescue cover is up.


Employers don’t seem to accept and fully understand the definition of a confined space or the requirements of the regulations and how it applies to them.

When talking to employers we come across the following:

  • “We have always done it that way and nobody has been injured”
  • “It’s not a confined space you can enter and exit easily”
  • “It’s not a confined space – we stop the carbon dioxide entering the vessel at the valve there”
  • “I know there is carbon dioxide in there; I can touch it”
  • “There’s no specified risk in there so it’s safe for me to weld in the vessel”
  • “There’s no gas in there so it’s safe” (there was no oxygen)

We have also come across the opposite situation, where employers have declared an area to be a confined space under the 1997 regulations with no specified risk being present.

These situations are often followed – sometimes years later – by a phone call and a request to attend the site as soon as possible and a “please don’t say ‘I told you so’.”

“if as a last resort the confined space must be entered then a safe system of work must be produced”

Definition of a confined space

A “confined space” means any place, including any chamber, tank, vat, silo, pit, trench, pipe, sewer, flue, well or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk.

To be clear the above definition is taken directly from the regulations. The guidance contained in the regulations goes onto expand this further to include:

Ducts, culverts, tunnels, boreholes, bored piles, manholes, shafts, excavations, trenches, sumps, inspection and machine pits, freight containers, ballast tanks, ships’ engine rooms and cargo hold, buildings and building voids, plant rooms and compartments, asbestos storage areas (for removal), areas where material that can oxidise is stored (rust), e.g. steel chain or wood hopper tanks, unventilated or inadequately ventilated rooms and silos, interiors of machines, plant and vehicles.

It must also be remembered and taken into account that a confined space can be created during manufacture or fabrication.

Therefore, to be deemed a confined space under the 1997 regulations the area needs to be entirely (but not always) enclosed and contain a reasonably foreseeable specified risk.

A specified risk is:

  • Serious injury to a person from a fire or explosion
  • The loss of consciousness of any person due to an increase in body temperature
  • The loss of consciousness of any person due to a gas, fume vapour or oxygen deficiency
  • Drowning
  • Asphyxiation due to a free flowing solid (e.g. grain store)
  • Entrapment in a free flowing solid (e.g. coal storage)

Requirements of the regulations

Firstly, as I am sure everyone already knows, the management of Health and Safety at work regulations (reg 3) requires a duty holder to take measures to manage risk by ensuring suitable and sufficient assessment of risks to workers and others is carried out. If more than five people are employed this assessment of risk must be documented.

This risk assessment should identify any confined space that comes under the control of the employer. During this risk assessment process, you must take into account that the work being carried out in the confined space may introduce a specified risk (welding, cutting use of chemicals etc.) The main principle of this risk assessment is to avoid entering or working in the confined space if at all possible. If as a last resort the confined space must be entered, then a safe system of work must be produced. This safe system of work must indicate the precautions to be taken when entering the confined space.

The stages of risk assessment:

  • Identify the hazards
  • Decide who might be harmed and how
  • Evaluate the risk and decide on precautions
  • Record your significant finding
  • Review your assessment and update if necessary

If you have a specified risk within a confined space, you must indicate who and how employees, who must be consulted with, (or others) will be harmed. For example, if the risk is fire from cutting or welding then there is the risk to all those in the immediate area of burns and to those further away from the effects of carbon monoxide poisoning (and more). You must then evaluate the risk, taking into account the likelihood and the impact of the risk harming someone and the level of severity. You then implement controls to reduce the risk to an acceptable level. You must then document your findings. Remember a risk assessment is never complete, it must be reviewed regularly. This is particularly important if any changes, such as in circumstances, information and technology become apparent.


The level of supervision required should be indicated by the risk assessment. The greater the risk the more supervision will be required. If the confined space work is routine (is there such a thing) and the risk is low and the precautions (controls) are straight forward then the supervision could be left in the hands of a worker within the confined space with a higher level of supervision or management checking in with the workers regularly. That said it is more likely that the risk assessment will indicate a requirement for a competent supervisor who will need to be in the confined space while the work is on-going. The risk assessment may also make it clear that a permit to work system is required. This could be due to the complexity of the confined space entry (multiple work points or difficult travel) or due to other work in the area of the confined space. The supervisor’s role will be to ensure that all the controls required by the risk assessment are being implemented properly as necessary and the communications with all involved in and working near the confined space is carried out effectively.


The Health and Safety Executive has several definitions of competence available to them. One is “competent” in relation to a person, meaning a person with sufficient training and experience, or knowledge and other qualities, to enable that person properly to undertake the duties assigned to that person, and “competence” is to be construed accordingly.

The confined space regulations are very clear, and to enter and work in confined spaces employees (or others) must be competent.

Following the introduction of the confined space regulation in 1997 the HSE did not notice a significant improvement in the accident and incident rate. This they put down to a lack of competence in entering and working in confined spaces. They established a working group from within the utilities sector. This was mainly the water industry, but included representation from the energy sector, training providers and standard setting organisations etc.

From this working group a National Occupational Standard (NOS) was developed and produced. This standard is what all confined space training whether in house or otherwise should be aimed at. The standard provides a minimum level of competence that potential confined space workers should achieve to be safe and productive in their job role.

To evidence competence the NOS provides a measurement that employees must achieve to be deemed competent to enter and work in a confined space. The assessment of competence is made up of two distinct subject areas:

  • Knowledge
  • Performance

Knowledge is what the employee should know, and performance is what they actually do in the confined space environment.

It should be noted that it is important the assessment is carried out in simulated conditions. If a candidate is being assessed in an area that comes under the confined space regulations, i.e. has an enclosed nature and a specified risk and the employee does not meet the minimum requirements of the NOS, then they should never have been allowed in the confined space as they are not yet competent and you are in breach of this requirement of the regulations.

For the reasons outlined above employers should be careful of allowing workers to enter and work in a confined space following an “awareness” training course. Without the required knowledge, experience, attitude and behaviours they may not be competent to be in the confined space.

The Standard required is the important point for employers and employees to be aware of. To assist in evidencing competence there are award bodies that have created qualifications based on the confined space NOS. These are regulated qualifications requiring verification to ensure that the quality of the training and assessment meets at least the minimum requirements of the NOS.

This competence requirement also applies to those supervising, managing and carrying out a rescue from a confined space.


No one should be allowed to enter or work in a confined space unless effective arrangements for their rescue are in place. These arrangements should include tried and tested methods of ensuring workers (and others) can safely and effectively be removed from the confined space. There should be first aid equipment available including, where required, resuscitation equipment. (see risk assessment)

The rescue arrangements (rescue workers and rescue equipment) should be capable of dealing with any identified specified risks that have been recorded on the risk assessment.

The regulations also make the point that the rescue arrangements also apply even if the rescue requirement is not caused by a specified risk. For example, if a worker has a slip, trip or fall within the confined space and cannot extract themselves from the space then the rescue provision has to cater for this.

The regulations are also very clear that for the rescue arrangements to be effective they must be capable of being implemented immediately. The reason, for example, for this being included in the regulations is that if the specified risk is an oxygen deficient atmosphere then you have less than four minutes to save the employees from life changing injuries. Beyond this timeframe they may potentially suffer brain damage and possibly become a fatality.

When an update was issued to the regulations it was clarified that relying on the public emergency services alone would not be in compliance with the rescue arrangements required by the regulations. This is for the reasons outlined previously in this article. With the best will in the world, if the public emergency services (fire and rescue service, ambulance etc) have to travel to the site then the likelihood of a rescue being successful is extremely unlikely.

It is, however, good practice to inform the local emergency services of any activities being undertaken in a confined space. This is especially relevant if the work will be ongoing for some time. It is also good practice to have someone, normally a top man, who will not be required to enter the confined space but can act as a liaison between those in the confined space and the local emergency services if they are called to assist in an emergency.

The information that the top man should have is:

  • Numbers of people involved in the work and in the rescue
  • Nature of the work
  • Equipment in use
  • Equipment available
  • Details of the incident (including injuries if any)
  • What has been done
  • What is planned to be done
  • Contact numbers for both the supervision and management


Do not enter the confined space unless you have no choice. Locate and categorise your confined spaces and ensure they are clearly marked. There are apps available that will assist in this.

Identify the hazards within the confined space and carry out a risk assessment based on these hazards. Introduce control measures to reduce the risks from the hazards to an acceptable level. (safe system of work). If necessary introduce a permit to work system. Have a competent workforce including management and supervision to implement the control measures. Put arrangements for rescue in place and test it as proof of effectiveness.

Always remember it is your confined space therefore it is your problem, deal with it.