Confined Spaces 

Section 4   Safety and Operational Procedures

Portable gas cylinders and internal combustion engines

4.8.25 

Petrol fuelled internal combustion engines must never be used in confined 

spaces. 

4.8.26 

Portable gas cylinders for heat, power or light, and diesel fuelled internal 

combustion engines are inappropriate for use in confined spaces unless 

exceptional precautions are taken. 

4.8.27 

Where their use cannot be avoided, adequate ventilation needs to be 

provided to prevent a build up of harmful gas, and to allow internal 

combustion engines to operate properly.  Fuelling of portable engine 

driven equipment should be conducted outside the confined space except 

in very rare cases. 

4.8.28 

Gas equipment and gas pipelines must be checked for gas leaks before 

entry into the confined space and removed from the confined space at the 

end of all working periods. 

Gas supplied by pipes and hoses

4.8.29 

Pipes and hoses for conveying oxygen or flammable gases into a confined 

space must be controlled to minimise the risks.  At the end of all working 

periods except short interruptions, the external supply valves for pipes and 

hoses must be securely closed before the pipes and hoses are withdrawn 

from the confined space to a place that is well ventilated.  Where pipes and 

hoses cannot be removed, they should be disconnected from the gas supply 

at a point outside the confined space and their content safely vented. 

Fire Prevention 

4.8.30 

As a general rule flammable and combustible materials should not be 

stored in confined spaces that have not been specifically created or 

allocated for that purpose.  If they accumulate as a result of work they 

should be removed as soon as possible and before they begin to create a 

risk.  Where flammable materials need to be located in a confined space 

the quantity of material should be kept to a minimum. 

Lighting

4.8.31 

Adequate and suitable lighting, including emergency lighting, should be 

provided.  Lighting will need to be specially protected if used where 

flammable or potentially explosive atmospheres are likely to occur.  Other 

gases may be present that could breakdown thermally on the unprotected 

hot surfaces of a lighting system and produce other toxic products.  

Lighting may need to be protected against knocks (eg. by a wire cage), 

and/or be waterproof.  Where water is present in the space suitable 

plug/socket connectors protected by residual current devices (RCDs) 

suitable for protection against electric shock should be used.  The position 

of lighting may also be important, for example, to give ample clearance for 

work or rescue to be carried out unobstructed. 

Static electricity

4.8.32 

Static discharges and all sources of ignition should be excluded from 

confined spaces where there is a risk of a potentially flammable or 

explosive atmosphere.  All conducting items such as steel trunking and 

airlines should be bonded and effectively earthed.  If cleaning operations 

are to be carried out the risks posed by the use or presence of high 

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