Having identified the hazards, who might be harmed and how you must decide how likely it is that harm will occur and if it does occur, how bad it will be, i.e. the level of risk.
Risk is a combination of consequences, in terms of the severity of harm and the likelihood of those consequences occurring. When seeking to establish the likelihood of harm, the adequacy of existing controls should be considered. It is necessary to determine whether risks are tolerable, with whatever precautions are currently in place. If the risk is too high, additional controls will be needed.
Some risk assessment methods are complex and appropriate for special or particularly hazardous activities. For example, a risk assessment of a chemical process plant might require complex mathematical calculations of the probabilities of events that could lead to an uncontrolled release of chemicals.
In many circumstances, risk can be assessed using simpler methods and can be qualitative. These approaches typically involve more judgment, since they place less reliance on quantifiable data. In some cases, these methods will serve as initial screening tools, to determine where a more detailed assessment is needed.
The risk assessment method prescribed in this course uses a scoring system for evaluating the degree of severity of the consequences of exposure or interaction with the hazard and the degree of likelihood that those consequences will occur, considering the systems, procedures and controls in place to prevent it.
Take a look at this scenario and make a judgement about the consequences in terms of the probable severity of harm.
- Slight harm (resulting in no time off work)
- Minor harm (resulting in time off work, but no more than 7 days)
- Medium harm (resulting in more than 7 days off work)
- Major harm (resulting in a life-changing injury/illness)
Either 4 or 5 would be reasonable evaluations of probable severity.
Now that you’ve evaluated the consequence level, the likelihood needs to be evaluated.
- Very low likelihood (all controls in place)
- Low likelihood (most controls in place)
- Medium likelihood (some controls in place)
- High likelihood (very few controls in place)
- Very high likelihood (no controls in place)
Again, either 4 or 5 would be reasonable evaluations of probable likelihood.
Based on your evaluation of the consequence/severity level along with the likelihood level, what is the risk rating?
Now you have evaluated the risk, you’re in a better position to decide what to do about it. The chart provides an example.