In need of a confined space course in Perth?
There are a wide range of hazards that you are likely to encounter when operating in a confined space. It is important to know what they are, how to identify them and how to manage them safely.
According to Safe Work Australia’s Confined Spaces: Code of Practice, there are 16 major hazards associated with confined space. Here are the top five of them!
Too Small or Too Much Oxygen
If oxygen in a confined space is either used up or replaced by another gas, this may result in an oxygen-deficient atmosphere. This can lead to a number of health problems, including lack of coordination, tiredness, poor judgement, dizziness, fainting, behavioural changes, asphyxiation and, in some cases, death.
There are a number of situations in which the amount of oxygen in a confined space may fall below safe levels. As mentioned above, oxygen can sometimes be used or replaced by another gas during either biological or purging processes.
In addition, when metal rusts can remove oxygen from the atmosphere, as can “bacterial action,” i.e. processes such as fermentation. The ‘Confined Spaces: Code of Practice’ also shows that oxygen can be consumed during the combustion of flammable substances, as well as during activities such as welding and cutting. It could also be “grains, wood chips, soil or chemicals in sealed silos.”
The other side of the coin is true, too. Confined space, which contains too much oxygen, can also be hazardous and could put workers’ lives at risk. One of the major concerns associated with the oxygen-rich atmosphere is the increased likelihood of fire or explosion.
It’s much easier to start a fire in the air that contains a lot of oxygen. Zenith – a company specialising in Workers’ Compensation – also argues that “oil will ignite in the presence of pure oxygen.”
You may find yourself faced with an oxygen-enriched atmosphere if you have specific chemical reactions in the confined space in which you work. The decomposition of hydrogen peroxide, for example, will produce water and oxygen. Safe Work Australia also suggests that leakage from an oxygen tank or a piece of equipment could boost oxygen to unsafe levels.
Under normal circumstances, the air is made up of about 79% nitrogen and various other gases, such as argon and carbon dioxide. The remaining 21% is oxygen. Safe Work Australia states that oxygen levels between 19.5% and 23.5% are considered safe – anything below or above that is, however, hazardous to workers.
Engulfment
In some confined spaces, workers are at risk of being engulfed – i.e. swallowed or immersed in stored material. Work Safe Victoria uses grain, sand, flour and fertiliser as substances that could potentially engulf someone. Other examples include coal and coal products, sewage, plastics and many types of liquids.
If a person is engulfed by any of the materials mentioned above, they may be crushed or suffocated, which may result in serious injury or death.
Fires and Blasts
Fires and explosions are another danger that workers operating in confined spaces may have to contend with. These may occur if you perform tasks in a flammable atmosphere.
The Health and Safety Authority states that such an atmosphere may arise if and when flammable gases and liquids are present, or there is a “suspension of flammable dust in the air.” These alone, however, are not enough to cause fires and explosions. They must also be combined with the ignition source and the air to ignite.
Safe Work Australia’s “Confined Spaces: Code of Practice” states that, officially, the flammable atmosphere is “one in which flammable gas, vapour or mist is likely to exceed 5 per cent of its lower explosive limit (LEL).” Simply put, the LEL is the smallest amount of gas mixed with air that either burns or explodes.
According to the Department of Commerce, the LEL for natural gas is 5 percent gas for 95 percent air, while the LEL for LPG is 9.5 percent gas for 90.5 percent air.
In addition to flammable gases, the presence of flammable liquids also poses a risk in confined spaces. Such liquids include petrol, methylated spirits, kerosene and paint thinners, to name but a few. There is also the “combustible dust” referred to above, which refers to substances such as wood, floor and grain dust.
In order to prevent such gases, liquids and dust from causing fires or explosions, it is important that any and all sources of ignition are removed from the confined space. A number of objects and activities can act as ignition sources, such as flames, hot surfaces, electrical equipment, metal tools (which can cause sparks when metal surfaces are struck), internal combustion engines and even static electricity.
Limited Entrance and Exit
Many confined spaces are difficult to get in and out of because their entrances and exits are either small or difficult to access. For example, some confined spaces can only be entered or exited by means of ladders or hoists. While this would not usually be an issue, it can mean a difference between life and death if someone has a medical emergency while operating in a confined space.
Work Safe Victoria encourages all workers to consider how difficult it would be for the injured person either to leave the confined space themselves or to receive first aid in the event of a medical emergency. You should also take precautions, such as never working alone in a confined space and having a nearby coworker who can jump to your rescue if needed.
Dangerous Substances
There are many airborne contaminants that can build up in confined spaces and cause harm to workers. For example, any substance that is or has been stored in a confined space that is toxic, such as hydrogen sulphide, may be inhaled by workers, leading to unconsciousness and sometimes death if the situation is not properly managed.
Types of tasks performed by workers in confined spaces may also result in the release of hazardous substances and airborne contaminants. For example, a worker who paints in a confined space without proper ventilation systems or respiratory protection equipment (RPE) risks being overwhelmed by fumes and becoming dizzy and uncoordinated.
In addition, if “sludge, slurry or other deposits” are disturbed while workers are operating in confined spaces, this could lead to the release of materials such as asbestos or silica that are known to cause cancer and respiratory diseases.
Safe Work Australia adds that the location of a confined space can also determine whether or not its workers could be exposed to hazardous substances. If it is located near a gas or liquid-producing plant, facility, service or process, it could enter and accumulate in the confined space and put workers in real danger.
One example of this is the “Confined Spaces: Code of Practice” which illustrates the build-up of carbon monoxide in a confined space due to its proximity to LPG-powered forklifts.
The presence or likelihood of such hazardous substances becoming present in confined spaces must be determined before any work begins and the steps taken to either eliminate or reduce the risk they pose to workers.
If you want to learn how not only to identify, but also to manage, such hazards, a training course in confined spaces could be the answer.