Confined Spaces 

Section 4   Safety and Operational Procedures 

Isolation from gases, liquids, and other flowing materials

4.8.18 

A confined space will often need to be isolated from the ingress of 

substances that could pose a risk to those working within the space. 

4.8.19 

Methods of isolation include removing sections of pipe or duct, inserting 

blanks or locking shut valves with a safety lock. 

4.8.20 

Whatever means of isolation is used it must be tested to ensure it is 

sufficiently reliable by checking for substances in the confined space to 

see if isolation has been effective. 

Isolation from mechanical and electrical equipment 

4.8.21 

Some confined spaces contain electrical and mechanical equipment with 

power supplied from outside the space.  Unless the risk assessment 

specifically enables the system of work to allow power to remain on, either 

for the purposes of the task being undertaken or as vital services (i.e. 

lighting, vital communications, fire fighting, pumping where flooding is a 

risk, or cable distributing power to other areas) the power should be 

disconnected, separated form the equipment, and a check made to ensure 

isolation has been effective.  Isolation must be controlled by the 

Authorised Person (Electrical) and safety locks used where practicable.

Personal Protective Equipment

4.8.22 

All persons entering a confined space shall be equipped with suitable 

personal protective equipment (PPE) including respiratory protection 

equipment (RPE) where necessary.  PPE provided will depend on the 

hazards identified but may include: 

n 

fall arrest / rescue harness to an approved standard 

n 

safety helmet to an approved standard 

n 

suitable RPE 

n 

portable atmosphere monitoring equipment 

n 

suitable clothing eg. gloves, overalls, boots, etc. 

n 

safety / rescue lines 

4.8.23 

The provision of PPE must be in accordance with the requirements of the 

Personal Protective Equipment at Work Regulations and Health and Safety 

Executive Guidance on the regulations (see JSP 375). 

4.8.24 

RPE will not normally be suitable unless it is breathing apparatus.  RPE of 

the canister respirator type or cartridge type does not protect from the risk 

of being overcome by high concentrations of fumes or oxygen deficiency 

and, as such, is not generally appropriate for confined space working. 

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April 2005