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A number of people are killed or seriously injured in confined spaces each year, and those not only include people working in confined spaces, but those trying to rescue them without proper training and equipment.
Ideally, working in confined spaces should be avoided, but in situations when this is not reasonably practicable it is imperative to identify the hazards present, assess the risks and determine what precautions are essential to protect individuals undertaking this type of work.
What is a confined space?
• Has restricted means of entry and exit and is not intended as a regular workplace
• Is at atmospheric pressure during occupancy and could have inadequate ventilation and/or atmosphere which may become contaminated or oxygen deficient
• It is a place that is substantially – though not always entirely – enclosed
• There will be a reasonably foreseeable risk of serious injury from hazardous substances or conditions within the space or nearby
Confined space is also a space that meets these three criteria:
• Large enough to enter and perform work in
• Has limited means of entry and exit
• Is not designed for continuous human occupancy It 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.
Key questions to ask relating to confined space awareness:
• What can cause harm?
• What are you going to do about it?
• Have I done enough?
Confined spaces can include:
• Areas with limited openings such as storage tanks, silos, reaction vessels, enclosed drains, sewers
• Open-topped chambers such as vats, combustion chambers, ductwork
• Closed, unventilated or poorly ventilated rooms
There are many types of industry which typically require employees to work in confined spaces.
• Workers may have to work in silos, trenches, tops of masts or unventilated or poorly ventilated rooms
• Surveyors working on building or settings may have to crawl underneath floorboards or in cellars
• Telecommunications engineers may have to work in enclosed drains or sewers
• Workers cleaning out and maintaining storage tanks, open topped chambers, tunnels and vats
• Workers maintaining or installing equipment, service cables and pipes in ductworks
• Repairing a dome at the top of an industrial chimney
• Please note that confined spaces do not need to be below ground level
Working safely in a confined space
Can you avoid entering the confined space at all? Consider the following:
• Can the work be done another way so that entry or work in confined spaces is avoided?
• If no, you must ensure that any work carried out in a confined space, where there is a reasonably foreseeable risk of serious injury, is properly controlled in a safe manner
• Better work planning or a different approach can reduce the need for confined space working
Ask yourself if the intended work is really necessary, or could you:
• Modify the confined space itself so that entry is not necessary
• Have the work done from outside, for example blockages cleared in silos by use of remotely operated rotating flail devices, vibrators or air purgers
• Can inspection, sampling and cleaning operations be done from outside using equipment and tools?
• Can remote cameras be used for internal inspection of vessels?
Assess the risks of confined spaces
• Carry out a risk assessment to identify potential hazards to safety caused by work in confined spaces
• Assess the level of risk the hazards pose
• Decide whether you need to take steps to manage these risks, including putting emergency arrangements in place
Anyone working in confined spaces is also at risk from physical dangers such as knocking their head or limbs against protruding structures such as metal struts or wooden support beams.
Staffing issues for confined space work
You will need to ensure you have the following staff members in place for the safe running of a confined space:
• Competent person: means a person with sufficient theoretical knowledge and practical experience to make an informal assessment of the likelihood of a dangerous atmosphere being present or subsequently arising in the space
• Responsible person: means a person authorised to permit entry to a confined space and having sufficient knowledge of the procedure to be followed
Safe systems of work
• If you must enter a confined space make sure you have a safe system for working inside the space
• Use the risk assessment to help identify the necessary precautions to reduce the risk of injury
• These will depend on the nature of the confined space, the associated risk and the work involved
• Make sure the safe system of work, including the precautions identified, is developed and used
• Everyone involved will need to be properly trained and instructed to make sure they know what to do and how to do it safely
Appointment of a supervisor
• Supervisors should be given responsibility to ensure that the necessary precautions are taken, to check safety at each stage and may need to remain present while work is underway
Are persons suitable for the work?
• Anyone working in a confined space must be appropriately trained for the task in hand
• Where risk assessment highlights exceptional constraints as a result of the physical layout, are individuals of suitable build?
• Are there any medical conditions that could be triggered or made worse by working in confined spaces, such as a bad back, claustrophobia or breathing problems such as asthma?
• If staff smoke, be aware smoking is banned in any substantially enclosed public places, workplaces or company vehicles used by more than one person
• You must display a no-smoking sign at the entrance to your premises and in vehicles
Confined space hazards
• Heat stress/exhaustion – If the body can’t cool itself through sweating, heat exhaustion or heat stroke can occur
Heat stroke symptoms:
• Dry pale skin with no sweating
• Hot red skin that looks sunburned
• Headache, dizziness, weakness, confusion, vomiting, fainting, pale clammy skin
• Call for an ambulance, move victim to cool area, loosen heavy clothing, place icepacks at armpits and groin, remove heavy clothing, drink cool water
How to protect yourself:
• Work during coolest part of the day, use spot ventilation, and use buddy system
• Drink plenty of cool water, a cup every 15 minutes, take frequent breaks
• Avoid alcohol or caffeine, certain medications may increase risk
Permit to Work Procedure:
• The employee must ensure that a suitable series of procedures are established to ensure that potential hazards are evaluated and minimised by a ‘Permit to Work’ system
• Many countries have legalisation which requires certain procedures
• A ‘Permit to Work’ must be issued by a ‘competent person’ every time entry is required to a confined space Isolation:
• Mechanical and electrical isolation of equipment is essential if it could otherwise operate, or be operated, inadvertently
• If gas, fume or vapour could enter the confined space, physical isolation of things such as pipe work needs to be ensured and in all cases a check should be made to ascertain that isolation is effective
Cleaning before entry:
• This may be necessary to ensure fumes do not develop from residues while the work is being done Check the size of the entrance:
• Is it big enough to allow workers wearing all the necessary equipment to climb in and out easily, and provide ready access and egress in an emergency?
• For example, the size of the opening may mean choosing air-line breathing apparatus in place of self-contained equipment which is more bulky and therefore likely to restrict ready passage
Provision of ventilation:
• You may be able to increase the number of openings and therefore improve ventilation
• Mechanical ventilation may be necessary to ensure an adequate supply of fresh air
• This is essential where portable gas cylinders and diesel fuelled equipment are used inside the space, because of the dangers from build up of engine exhaust
• Warning: carbon monoxide in the exhaust from petrol-fuelled engines is so dangerous that use of such equipment in confined spaces should never be allowed
Testing the atmosphere:
• Tested from the outside and found to be normal before each entry
• You must check that it is free from toxic and flammable vapours and that it is fit to breathe
• Testing carried out by a competent person using a suitable gas detector which is correctly calibrated
• Where the risk assessment indicates that conditions may change
• Monitored continually throughout the period of entry
• If the atmosphere test detects an IDLH environment, entry is prohibited until a permit to work is issued, or alternative arrangements have been made
• Electronic monitoring equipment is to be capable of detecting oxygen levels, toxic gases, and flammable and explosive atmospheres
• Alarms on the atmosphere monitor should be capable of activating below the harmful atmosphere levels, on battery failure or on any other fault
Monitors are to be calibrated and tested regularly by a competent person Ventilation – all available confined spaces access points are to:
• Be opened to permit air circulation
• Remain open and guarded throughout the period entry
• Provide sufficient mechanical means when natural ventilation is ineffective
• Communicate the work method and appropriate risk controls to all relevant workers when purging is deemed necessary
• The confined space is to be ventilated by natural or mechanical means and the atmosphere re-tested after purging and before entry commences
• The atmosphere in the confined space is to be tested and purged or ventilated after cleaning, as necessary
• Care is to be taken if residues are to be removed since trapped gases or fumes may be released, giving rise to an IDLH atmosphere. (Note: similar care is to be taken if residues are found after entry to the confined space) Isolating the confined space:
• The confined space is to be isolated from any pipework or power supplies before entry commences
• Isolations are to be carried out under a permit to work
• Respiratory protection equipment (RPE), personal protection equipment (PPE) and other associated safety equipment are to be identified and recorded in the risk assessments
• Authorised confined space workers are to be trained and assessed as competent in the use of all the safety equipment
• All equipment is to be inspected, tested and maintained
• Where potentially flammable or explosive atmospheres exist, all safety equipment and lighting is to be intrinsically safe, earthed and bonded as necessary to prevent the build up of static
• All other tools for use in potentially flammable or explosive atmospheres are to be non-sparking
• Look for the marking to indicate that the equipment has been tested as being intrinsically safe (explosion proof)
Provision of special tools and lighting:
• Non-sparking tools and specially protected lighting are essential where flammable or potentially explosive atmospheres are likely
• In certain confined spaces (e.g. inside metal tanks) suitable precautions to prevent electric shock include use of extra low voltage equipment (typically less than 25 V) and, where necessary, residual current devices
Provision of breathing apparatus:
• This is essential if the air inside the space cannot be made fit to breathe because of gas, fume or vapour present, or lack of oxygen
• Never try to ‘sweeten’ the air in a confined space with oxygen as this can greatly increase the risk of a fire or explosion
Preparation of emergency arrangements:
• This will need to cover the necessary equipment, training and practice drills
Provision of rescue harnesses:
• Lifelines attached to harnesses should run back to a point outside the confined space
• An adequate communication system is needed to enable communication between people inside and outside the confined space and to summon help in an emergency
Check how the alarm is raised:
• Is it necessary to station someone outside to keep watch and to communicate with anyone inside, raise the alarm quickly in an emergency, and take charge of the rescue procedures?
Is a ‘permit to work’ necessary?
• A permit to work ensures a formal check is undertaken to ensure all the elements of a safe system of work are in place before people are allowed to enter or work in the confined space
• It is also a means of communication between site management, supervisors, and those carrying out the hazardous work
Essential features of a permit to work are:
• Clear identification of who may authorise particular jobs (and any limits to their authority) and who is responsible for specifying the necessary precautions,
e.g. isolation, air testing or emergency arrangements
• Provision for ensuring that contractors engaged to carry out work are included
• Monitoring and auditing to ensure that the system works as intended
Access and egress:
• All employees entering a confined space are to be logged in and out
• Confirm that all workers have exited the space before the openings are closed and the site vacated
• Suitable lifting equipment is to be used to facilitate entry and exit when entry is via a vertical shaft
• Determine whether workers are to remain attached to the lifting equipment
• Flammable or combustible materials are not to be stored in a confined space
• All potentially flammable waste material from the work activity is to be removed from the confined space and disposed of in a safe manner
• Gas appliances and internal combustion engines are not permitted in confined spaces
• Appropriate fire fighting equipment is to be available at confined spaces when it is deemed necessary
Emergencies and rescue procedures:
• When things go wrong, people may be exposed to serious and immediate danger
• Effective arrangements for raising the alarm and carrying out rescue operations in an emergency are essential
• Contingency plans will depend on the nature of the confined space, the risks identified and consequently the likely nature of an emergency rescue • Emergency arrangements will depend on the risks
• Rescue coordination may involve various stakeholders
• Coordinate the rescue arrangements with the statutory emergency services
• Inform the emergency services of all potentially hazardous confined spaces
• Alert all necessary personnel
You should also consider the elements listed below.
• How can an emergency be communicated from inside the confined space to people outside so that rescue procedures can start?
• Don’t forget night and shift work, weekends and times when the premises are closed, e.g. holidays
• Also, consider what might happen and how the alarm can be raised
Rescue and resuscitation equipment:
• Provision of suitable rescue and resuscitation equipment will depend on emergencies identified
• Where such equipment is provided for use by rescuers, training in correct operation is essential
Capabilities of rescuers:
• They need to be properly trained people, sufficiently fit to carry out their task, ready at hand, and capable of using any equipment provided for rescue, e.g. breathing apparatus, lifelines and fire-fighting equipment
• Rescuers also need to be protected against the cause of the emergency
• It may be necessary to shut down adjacent plant before attempting emergency rescue
First aid procedures:
• Trained first aiders need to be available to make proper use of any necessary first aid equipment provided
Local emergency services:
• How are the local emergency services such as the fire brigade made aware of an incident?
• What information about the particular dangers in the confined space is given to them on their arrival?
Deciding if a location is a confined space or not isn’t the easiest question to answer and is only part of the answer to establishing safety. More importantly, you have to consider the level of protection that will be required. If you were entering a sewer you would expect it to be very compliance-driven; the trouble is, a lot of people never even consider that dragging a propane heater into a port-a-cabin or the site hut contravenes every law in the confined space safety book.
The truth is that all too often, what may sound like a good idea at the time may in fact be tantamount to suicide, or death by misadventure. ? References 1 ILO Ergonomic Checkpoints and Various other Lead Bodies relating to CSPR 2 Confined Spaces Regulations 1997. L101 HSE Books 1997 ISBN 0 7176 1405 0 3 Guidance on permit to work systems: HSG250 HSE Books 2005 ISBN 0717629430 4 The safe isolation of plant and equipment: HSG 253 HSE Books 2006, ISBN 9780717661718
David Whiting, Safety Business Services (SBS) Ltd
David Whiting has been an instigator of change in Health and Safety presentations and training. His energetic, interactive seminars and workshops have instilled confidence in countless people around the world. In short, he helps people exceed their goals.
David is a charted member of the Institute of Health and Safety (IOSH) and Company Director of Safety Business Services (SBS) Ltd: this is an associate consultant service with more than 35 years of occupational health, safety, corporate governance, contingency planning, supply chain and risk management experience working in both private and public sector environments.
Particular area of expertise is the implementation of management systems with experience in developing or delivering training programmes, courses covering general safety and risk management or specific topics, across a broad range of industries.
David and his associates are proud to be working in partnership with IMS Certification FZE and National Academy and can be contacted on their stand at the Intersec trade fair.
Published: 10th Nov 2011 in Health and Safety Middle East
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