Confined spaces are commonly found in silos, vats, tanks, chimneys, pipes, ducts, tunnels or other similar enclosed or partially enclosed structures, underground sewers, trenches, etc.
It should be noted that other hazards such as inadequate ventilation, noise, heat, cold, chemicals etc. can pose a greater risk when in a confined space.
For example, trenches are not considered confined spaces based on the risk of structural collapse alone, but will be confined spaces if they potentially contain concentrations of airborne contaminants that may cause impairment, loss of consciousness or asphyxiation.
It is always best to remove the need for a person to enter a confined space. However this is not always possible, therefore control measures need to be put into place to minimise the risk to your workers. Workers may have to enter a confined space to inspect, test, repair or for regular maintenance and cleaning. Whatever the reason, any space above or below the ground with poor ventilation should be treated as Confined and Dangerous.
Confined spaces are considered to be high risk due to the known dangers that can be identified within the space.
Maintaining an atmosphere that is fit to breathe inside a confined space can be difficult as fumes and gases may build up and displace the oxygen present. This presents one of the most serious hazards, since lack of oxygen, or the presence of a toxic, explosive, flammable or inert gas cannot be seen and more often than not cannot be smelled either. The danger is that a worker could unwittingly enter what seems to be a perfectly normal area and quickly find out that it is not.
Oxygen Deficiency – Asphyxiation
19.5% to 21% of the air in the space is considered normal, safe oxygen levels.
At 16% you’ll start developing symptoms like fast breathing & heartbeat, drowsiness and nausea.
At 12% you’ll be unconscious
At 6% you’ll be dead.
These symptoms can come quickly. Make sure the confined space is fully tested by a qualified person trained in ‘Confined space Entry’ before anyone enters the confined space.
Fire and Explosion
There can be a real danger that flammable gas and vapour may collect in a confined space, and these may ignite when welding or cutting takes place leading to an explosion.
Fuel gas processes increase the risk of fire and explosion particularly if leaking equipment is left in the confined space, allowing a build-up of fuel gases or oxygen. Any heat from welding or cutting, or just an electric spark, can then result in a fire or explosion. When using fuel gas processes extra care should be taken to ensure that the equipment is not leaking, as this can result in build-up of gas and possible explosion.
Oxygen should never be used to enrich the atmosphere in a confined space. It is a severe fire and explosion hazard.
Engulfment is when a person is suffocated or crushed by liquid or “flowing” solid material, it means to plunge into and be immersed by material. It may result in injury or death from asphyxiation or from being crushed by loose granular material stored in containers such as silos, bins, and hoppers.
Suffocation can occur when a worker enters a confined space such as a silo or bin and is engulfed by grain or when bins develop hazardous atmospheres or do not have enough oxygen. A worker can be engulfed or suffocated
Falls and Entrapment
Due to the difficult and restricted entry and exit it is easy for someone to trip, stumble or fall whilst getting into or out of the space. Merely slipping on a wet or greasy floor inside a confined space can be serious, the casualty could become trapped in a position where his breathing may be restricted and he may suffocate.
Precautions to avoid trips and falls are basically common sense, good housekeeping and vigilance. Keep floors inside the space as dry, grease-free and free from obstructions as far as possible.
Work Health and Safety duties in relation to a confined space
A person conducting a business or undertaking (PCBU) has the primary duty under the WHS Act to ensure, so far as is reasonably practicable, that workers and other persons are not exposed to health and safety risks arising from the business or undertaking.
The WHS Regulations include specific obligations on a person conducting a business or undertaking who has management or control of a confined space.
A confined space means an enclosed or partially enclosed space that:
• is not designed or intended primarily to be occupied by a person; and
• is, or is designed or intended to be, at normal atmospheric pressure while any person is in the space; and
• is or is likely to be a risk to health and safety from:
o an atmosphere that does not have a safe oxygen level, or
o contaminants, including airborne gases, vapours and dusts, that may cause injury from fire or explosion, or
o harmful concentrations of any airborne contaminants, or
Workers must take reasonable care for their own health and safety and that their work does not adversely affect the health and safety of other persons. Workers must comply with any reasonable instructions given relating to confined space entry permits, risk control measures and emergency procedures, and should carry out work in a confined space in accordance with any relevant information and training provided to them.
Any work performed in a confined space should be performed in accordance with the requirements of Safe Working in a Confined Space – Australian Standard AS2865-1995. The objectives of this standard are to provide guidance to eliminate or, where this is not practicable, minimize the need to enter confined spaces; and provide for the health and safety of all persons who need to enter or work in confined spaces by preventing exposure to hazards which may otherwise be experienced when working in a confined space, and thereby prevent collapse, injury, illness or death arising from exposure to those hazards.”
Ensure workers who have to enter a confined space undergo approved training – The courses offered at AlertForce are in line with the most recent safety legislation. AlertForce offers the Confined Spaces Work & Enter, a 1-day course, and the Advanced Confined Spaces Work & Enter, a 2-day course. For those requiring a gas test atmospheres certificate, the ability to supervise other workers or to issue work permits, this advanced course offers a much more in-depth understanding of working in confined spaces.
When looking at ways to reduce the risk of working in a confined place, consider the following:-
• Identify each confined space your workers need to carry out their work in
• Identify the reasonably foreseeable hazards associated with working in the space.
• Engage a suitably qualified person to undertake a risk assessment before any work is carried out in a confined space for the first time – only a person who is able to identify hazards (such as oxygen deficiencies or the presence of toxic gas) is qualified to undertake a risk assessment. (Refer to the AlertForce Advanced Confined Spaces course)
• Implement appropriate controls for identified hazards if elimination is not possible.
• Regularly review the risk assessments (before each entry into the confined space).
• Use signage to identify the confined space as a restricted access area.
• Identify and document accountabilities and responsibilities of workers who work in confined spaces, such as;
o The capacity to assign, control, delegate
o Review the confined space safety procedures
o Issue and receipt of entry permits,
o Standby and emergency response
o Training and competency assessment.
• Regularly review emergency response procedures
• Ensure your workers know how to and use the personal protective equipment appropriate to the specific confined space, e.g. respiratory protection devices, harness/lifelines, eye protection, etc.
• Make sure that you keep records of:
o The location of confined spaces;
o Training conducted;
o Risk assessments and risk control measures;
o Inspection, calibration and maintenance of confined space safety and rescue equipment;
o Inspections and audits of confined spaces; and
o Reports related to any incident associated with the confined space.
The Code of Practice, Confined Spaces, provides practical guidance for managing the risks of confined spaces and has a helpful flow chart to assist in identifying confined spaces.
For more information on the courses that we offer click on confined space training
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