Once the level of risk has been assessed, attention now needs to be focused on controlling the risk. This may mean tolerating the level of risk by maintaining current controls, or putting in place additional controls to reduce the level of risk.
Legally, there is a requirement to do all that is “reasonably practicable” to protect people from harm. This requires the degree of risk (likelihood x consequences) of a particular activity or environment etc. to be balanced against the costs in terms of time, trouble and physical difficulty of taking measures to reduce the risk.
The concept can be visualised by thinking about it as a set of scales, with the level of risk on one side and the costs involved in controlling that risk on the other.
The greater the risk, the more likely it is that it will be reasonable to go to very substantial expense and trouble to reduce it.
But if the risk is low, the same substantial expense would be considered disproportionate to the risk and it would be unreasonable to have to incur them to address a low risk.
The aim is to find the balance. There is no magic formula for working this out – it comes down to the competence and judgement of those involved in the risk management process.
The HSE provide the following extreme example to illustrate the concept:
- To spend £1m to prevent five staff suffering bruised knees is obviously grossly disproportionate; but
- To spend £1m to prevent a major explosion capable of killing 150 people is obviously proportionate.
