4. Risk management
4.1 General
4.2 Hazards and risks
4.3 The risk management process
4.4 Common electrical hazards
4.1 General
This Code of Practice should be used on the basis that appropriate workplace health and safety risk management processes are applied. This section examines the basics of such a process.
4.2 Hazards and risks
Hazards and risks are NOT the same thing. A hazard is something with the potential to cause harm. This can include substances, plant, work processes or other aspects of the work environment. Risk is the likelihood that death, injury or illness might result because of the hazard.
For example, the energy in electricity, that has the potential to cause an electric shock and result in a serious or even fatal injury, is a hazard. The associated risk is the likelihood that a worker might be electrocuted when they come in contact with exposed live electrical parts.
The relationship between hazard and risk is sometimes represented simply as:
Risk = Hazard X Exposure
In the above relationship, the terms:
- "Exposure" would cover factors such as frequency of exposure to the hazard and probability of an incident caused by the hazard, and
- "Hazard" would include the possible consequences of an incident due to such a hazard eg death, severe injury or property damage or both.
4.3 The risk management process
There are five basic steps in the risk management process, as follows:
- Identify the hazards present in a particular work situation. If there is a regulation or ministerial notice about the hazards, you must implement those requirements.
- Assess the risks of injury or property damage that may result from the hazards. This step will help to determine the level of risk associated with the identified hazards and establish a priority list based on the risk level of each hazard. The desired outcome is a priority list for control measures.
- Decide on control measures to eliminate the hazard or minimise the level of the risks of injury or property damage. If there is a code of practice, you must either do what the code says or adopt another way to manage the exposure to the risk. The preferred hierarchy of control is:
- Eliminate the hazard;
- Substitute with a less hazardous material, process or equipment;
- Redesign equipment or work process;
- Isolate the hazard;
- Introduce administrative controls; and
- Use appropriate personal protective equipment.
In deciding which control measures to adopt, you should start at the top of the hierarchy and work your way down.
- Implement the control measures; and
- Monitor and review the effectiveness of the control measures. It may be necessary to modify the control measures or the way they were implemented if the measures were not effective or if new problems arose because of the implementation of the original control measures.
The five steps of the risk management process are illustrated in Figure 1.
Figure 1 – The risk management process
4.4 Common electrical hazards
4.4.1 Electrical hazards and causes of injury
The common electrical hazards and causes of injury can be broken into three broad categories. These categories are:
- Electric shock causing injury or death. The electric shock may be received by direct contact, tracking through or across a medium, or by arcing;
- Arcing, explosion or fire causing burns. The injuries are often suffered because arcing or explosion or both occur when high fault currents are present; and
- Toxic gasses causing illness or death. Burning and arcing associated with electrical equipment causes a range of gases and contaminants to be present. Compounds ranging from ozone to cyanide and sulphuric acids can be present as well as the hazards such as low oxygen content in the air.
The three common electrical hazards may be present individually or combined.
For example, if a fault occurred in the main switch-room of a large shopping centre all three of the electrical hazards could be present. The presence of step and touch potentials10 should be addressed as well as the potential for an explosion. Further, burning materials such as PVC and epoxy resins can cause the atmosphere to become hazardous.
Parts that are normally energised or that may become energised under fault conditions must be treated as live until the parts are proven de-energised.
The categories of common electrical hazards, listed above, are relatively clear. However, as electricity is not usually detected by sight, smell or sound, the identification (or recognition of the potential) of the hazards can be more difficult. Refer to section 4.3 of this Code for guidance regarding the identification of hazards and section B.1 for further information on electrical hazards.
Areas, outside the scope of this Code, that should also be addressed include:
- The flammable atmosphere in battery rooms or hazardous locations;
- Working in confined spaces;
- Electric field strength and magnetic field strengths. These fields, especially if the source of the field is a direct current, can cause interference with cardiac pacemakers and other medically implanted electronic devices. Precautions should also be taken to prevent other hazards such as flying metal objects.
- Preventing falls, eg when working at height;
- Use of explosive powered tools;
- Working on roadways;
- The use of hazardous substances such as poisons, chemicals, solvents, synthetic resins, forms of asbestos and polychlorinated biphenyls (PCB);
- The use of flammable gases such as liquid petroleum, oxygen, acetylene etc; and
- The use of explosives.
10 The term "step and touch potential" is defined in Appendix A.
Last updated July 16, 2009
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