Confined Spaces 

Section 4   Safety and Operational Procedures 

4.2.10 

The Authorised Person must ensure that there is a formal means of 

communicating the results of the general risk assessment to the persons 

involved in or affected by confined space working. The results of the task 

specific risk assessment should be included in the Safety Method 

Statement and taken account of in the safe system of work. 

Factors to Be Assessed 

4.2.11 

The general condition of the confined space to identify the potential 

presence of hazards.  Any records relating to the space should be checked 

for relevant information. 

4.2.12 

Information about any substances previously held in a confined space 

indicating what kind of hazard may be encountered, e.g. toxic or 

flammable gases. 

4.2.13 

Dangers arising from any residues remaining in the space, e.g. sludge.  

Where there are residues safe working procedures should assume that 

disturbance of the residue will release fumes. 

4.2.14 

Contamination from adjacent plant, processes, surrounding land, soil or 

strata by gases and liquids. 

4.2.15 

Potential oxygen deficiency or oxygen enrichment. 

4.2.16 

The dimensions and layout of the confined space. 

4.2.17 

The need for isolation of the confined space to prevent dangers arising 

from outside.  There may be a risk of substances (liquids, gases, steam, 

water, raw material) from near by processes and services entering the 

confined space. 

4.2.18 

Certain confined spaces can be affected by external events, eg. water 

surges from pumping station operation, heavy rainfall upstream, etc. 

4.2.19 

Hazards arising from the work to be undertaken in the confined space or 

materials taken into the confined space, eg. chemical cleaning, welding 

etc.  Where such work is undertaken a specific risk assessment is to be 

undertaken to determine the safe working methods. 

4.2.20 

The possibility of exposure to both employees and non employees in the 

vicinity of a confined space from vented gases must be taken into account. 

4.2.21 

Emergency rescue arrangements. 

4.2.22 

Isolation of plant and equipment within the confined space. 

4.3   

DEFINING FEATURES OF A CONFINED SPACE

4.3.1  

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. 

4.3.2  

 Specified risk  means a risk of : 

n 

serious injury to any person at work arising from a fire or explosion 

n 

without prejudice to the above bullet point:  

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April 2005