SAFed Health and Safety Passport Scheme

Module 16 — Confined Spaces

16.1            Introduction

This document forms one of a series of modules on various health and safety subjects that comprise the examinable material considered necessary for the award of the SAFed Health and Safety Passport.

When you have studied this module you should have acquired sufficient knowledge to be able to answer the questions detailed at the end of the module.  Upon satisfactory completion of all modules, you will be eligible to undertake the final assessment for the award of the SAFed Health and Safety Passport.

The SAFed Health and Safety Passport is issued to Engineer Surveyors by the Health and Safety Manager of their employing company upon satisfactory completion of the Safety Passport final assessment.

The award of the SAFed Health and Safety Passport provides evidence that the holder of the Passport has the appropriate knowledge and awareness in health and safety matters considered necessary for an Engineer Surveyor to undertake the duties for which they are authorised by their employing company.

The passport is valid for a maximum of three years.

16.2     Key Objectives

Having studied the module you should have an awareness of:

·         Legislation applicable to Confined Spaces

·         Precautions necessary before entry to a confined space is considered

16.3            Introduction to confined spaces

Under the Health and Safety at Work etc. Act 1974 (Section 2(2)[a]) companies have to provide and maintain safe systems of work that are, so far as is reasonably practicable, safe and without risk to health.  Further requirements for safe systems of work following upon risk assessments are contained in the Management of Health and Safety at Work Regulations 1999, which also place duties on employees to follow the systems and procedures set up for their protection following risk assessments.

The Confined Spaces Regulations 1997 require employers to: -

a)      follow a safe system of work if entry is unavoidable; and

b)      safeguard rescuers and make adequate emergency arrangements before starting work.

The Control of Substances Hazardous to Health Regulations 2002 require the employer to eliminate or control exposure to substances which may be hazardous to health and to provide the appropriate information, instruction and training to those who may be affected.

16.4     What is a Confined Space?

A confined space can be any space of an enclosed nature where there is a risk of death or serious injury from hazardous substances or dangerous conditions (e.g. lack of oxygen).

Some confined spaces are fairly easy to identify; e.g. enclosures with limited openings:

·         Storage tanks

·         Silos

·         Unfired pressure vessels

·         Boilers

Others may be less obvious, but can be equally dangerous, for example:

·         Open-topped chambers

·         Vats

·         Combustion chambers in furnaces etc.

·         Ductwork

·         Vehicle pits

·         Unventilated or poorly ventilated rooms

·         Lift pits (Under certain circumstances)

16.5     Hazard Identification

What are the Dangers from Confined Spaces?

Dangers can arise in confined spaces because of specified risk namely:

·         A lack of oxygen — This can occur:

a)      inside steel tanks and vessels when rust forms;

b)      in ships’ holds, freight containers, lorries etc as a result of the cargo reacting with oxygen inside the space.

c)      Oxygen deficiency monitors are one of many was of detecting (and protecting) against oxygen deprivation, these are designed to give a pulsating audible alarm automatically if the oxygen level should fall to a dangerous level.  Normal air contains 20.9% oxygen; oxygen levels below 19.5% by volume are considered unsafe and should this fall below 18%, immediate corrective measures must be taken.

·         Oxygen Enrichment — This can occur from damaged hoses on oxygen acetylene welding / burning equipment

·         Poisonous gas, fumes or vapour — These can:

a)      enter tanks or vessels from connecting pipes;

b)      build-up in sewers and manholes and in pits connected to the system.

c)      Carbon monoxide is one of many poisonous gases that is considered extremely dangerous, primarily because it is odourless, colourless and tasteless, which makes it extremely difficult to detect.  Should the atmospheric concentration of carbon monoxide exceed 3%, immediate corrective measures must be taken.


·         Liquids and solids — which can suddenly fill the space, or release gases into it, when disturbed.  Free flowing solids such as grain can also partially solidify or ‘bridge’ in silos causing blockages, which can collapse unexpectedly.

·         Residues — left in tanks, vessels etc, or remaining on internal surfaces, which can give off gas, fume or vapour.

·         Dust may be present in high concentrations, e.g. in flour silos.

·         Serious injury from fire or explosion

·         Increase in body temperature resulting in unconsciousness

16.6     Safe Practices

It is the policy of member companies to take all reasonable steps to secure the health and safety of employees who are required to make entry into confined spaces.  Member companies acknowledge that health and safety hazards may arise when entry into confined spaces is required.  It is the intention of the member companies to ensure that any risks are reduced to a minimum.

Member companies will provide sufficient information, instruction and training as is necessary to ensure the health and safety of employees who are required to enter into confined spaces and Engineer Surveyors should note that in all cases a second person should be in attendance outside the confined space at all times.

Should entry to a confined space necessitate the need for Breathing Apparatus, member companies shall ensure that individual Engineer Surveyors involved will receive the essential specialist training required.

16.7            Avoiding entering Confined Spaces

Whenever possible, check if the examination to be carried out can be done another way so that entry into confined spaces is avoided, for example: -

a)      inspection and sampling operations can often be done from outside the space using appropriate equipment, tools and techniques;

b)      remote cameras can, in certain circumstances, be used for internal inspection of vessels.

Wherever possible entry into confined spaces should be avoided; however where this cannot be avoided, with the proper precautions in place, there is no reason why Engineer Surveyors should not safely enter confined spaces during the course of their work.

The following 3 steps below will help to ensure that work is without significant risk.

i)                    Find out as much information about the confined space as possible, including details of any previous contents and their associated hazards.

ii)                  Never enter a confined space without the knowledge of others.

iii)                 Always prepare thoroughly for work and adhere strictly to the rules of any permit to work system that applies.


16.8            Emergency Procedures

Arrangements for emergency rescue will depend on the nature of the confined space, the risks identified and the likely nature of an emergency rescue.  To be suitable and sufficient the arrangements for rescue and resuscitation should include consideration of:-

a)      Rescue and resuscitation equipment;

b)      raising the alarm and rescue;

c)      safeguarding the rescuers;

d)      fire safety;

e)      control of plant;

f)       public emergency services; and

g)      training.

16.9            Summary of safe procedures

a)      who is in charge of the job?

b)      do the responsibilities overlap with anyone else’s?

c)      is there anything, which is not someone’s responsibility?

d)      has testing the atmosphere for oxygen level and/or toxic fumes been carried out?  

e)      has the confined space been isolated to prevent ingress of harmful agents (e.g. gases, vapours, liquids and free-flowing solids, etc? 

f)       has electrical and mechanical isolation been carried out? 

g)      has anyone checked that the equipment is right for the job?

h)      are safe ways of doing the job already in place?  

i)        could this job interfere with the health and safety of others?  

j)        are safe working procedures laid down for the job?  

k)      have people been trained and instructed in the use and limitations of equipment?  

l)        if the job cannot be finished today can it be left in a safe state? 

m)    are clear instructions available for the next shift?

n)      are the production people aware of what maintenance staff are doing and vice versa? 

o)      what might go wrong, e.g. accident, explosion, food poisoning, electrocution, fire, release of radioactivity, chemical spill?

16.10   End of module and next steps

Well done!  By reaching this point you will have finished studying this particular module.  You should now have sufficient knowledge to answer the questions contained at the end of the module.

Answers to the questions should be forwarded to your Health and Safety Manager.

Provided that you have answered the questions correctly, your Health and Safety Manager will forward to you your next self study module.

Click here to answer questions on Module 16