A Risk Matrix can be used to help you work out the level of risk associated with a particular issue. They do this by categorising the likelihood of harm and the potential severity of the harm. This is then plotted in a matrix (please see below for an example). The risk level (between 1 and 25) determines which risks should be tackled first. A score of 1 is 'very low risk', with the level of risk increasing to 'very high risk' with a score of 25.

Using a matrix can be helpful for prioritising your actions to control a risk. It is suitable for many assessments but in particular to more complex situations. However, it does require expertise and experience to judge the likelihood of harm accurately. Getting this wrong could result in applying unnecessary control measures or failing to take important ones.