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Updated: 21 April 2022

There are various hazards associated with work in confined spaces and these regulations were constructed to ensure that identifiable risks are suitably assessed and adequate control measures and emergency rescue arrangements are in place. The legislation defines a confined space as:

"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”

– Regulation 1: Citation, commencement and interpretation

It goes on to describe the specified risks that must be managed for compliance. Each risk can cause serious injury, loss of consciousness and/or asphyxiation or drowning to any person at work within a confined space; they are:

  • fire or explosion;
  • high temperatures;
  • gas, fumes, vapour or lack of oxygen;
  • an increase in the level of a liquid; and
  • a free flowing solid.

Employers must ensure that work in confined spaces carried out by employees (and their self) is done in a manner so it complies with the requirements outlined within the regulations. Self-employed individuals must similarly ensure that their own work is carried out in line with the regulations. 

Additionally, employers and the self-employed have a duty for compliance in respect to matters that are within their control when work in confined spaces is being carried out by other workers (who are not their employees).

The initial stage of the risk assessment will need to identify if the task can be carried out without the need to enter the confined space (i.e. avoid entry and carry out the work from outside). If no reasonable alternative to entry can be found, the risks must be suitably and sufficiently assessed by evaluating each hazard and implementing measures to safeguard workers and prevent injuries. Matters that need to be considered include the provision and suitability of:
  • a safe way in and out of the space;
  • formally documented safe systems of work (SSOW);
  • a written permit to work system;
  • information, instruction, training and supervision;
  • emergency rescue arrangements, whether or not arising out of the specified risk(s);
  • monitoring and maintenance of safe atmospheres (by testing the atmosphere prior to entry and providing personal detectors respiratory protective equipment (RPE));
  • materials and equipment (with thought given to hazards specific to their use in confined spaces); and
  • safeguards to prevent accidents, such as toe boards.

The potential for danger while working in a confined space must be re-assessed if it’s possible that the site has been affected by a change in weather conditions, temperature or other activities occurring nearby.

More guidance on managing the risks related to work in confined spaces can be found on our risk topic page.