APPENDIX C: A 5X5 RISK MATRIX FOR SEVERITY AND LIKELIHOOD
Table C1 describes a 5x5 risk matrix for severity and likelihood.
Table C1: A 5x5 Risk Matrix
Table C2 gives a guideline for severity ratings.
Table C2: Guidance for Severity Rating
Level
Severity
Description
1
Negligible
Not likely to cause injury or ill health.
2
Minor
Injury or ill health requiring first aid only (includes minor cuts and bruises, irritation, ill health with temporary discomfort).
3
Moderate
Injury requiring medical treatment or ill health leading to disability (includes lacerations, burns, sprains, minor fractures, dermatitis, deafness, work-related upper limb disorders).
4
Major
Serious injuries or life-threatening occupational disease (includes amputations, major fractures, multiple injuries, occupational cancer, acute poisoning).
5
Catastrophic
Fatality, fatal diseases or multiple major injuries.
Table C3 gives a guideline for likelihood rating.
Table C3: Guidance for Likelihood Rating
Level
Likelihood
Description
1
Rare
Not expected to occur but still possible.
2
Remote
Not likely to occur under normal circumstances.
3
Occasional
Possible or known to occur.
4
Frequent
Common occurrence.
5
Almost certain
Continual or very often repeated.
Table C4 describes the proposed actions for various risk levels.
Table C4: Proposed Actions for Various Risk Levels
Colour
Risk
Proposed actions
Extreme
Stop work and reduce risk.
High
High-priority action to reduce risk.
Moderate
Take action as early as possible.
Potential high
Very low probability but very high consequences. Apply fail-safe controls, regular audits, leadership reviews and effective monitoring.
