Guide to ANZS4024 Risk Ratings - H&R - Common

Key to Risk Assessment Ratings

Likelihood of Occurrence (LO)Frequency of Exposure (FE)
0.1Almost impossible/Possible in extreme circumstances0.1Infrequently
0.5Highly unlikely though conceivable0.2Annually
1Unlikely but could occur1Monthly
2Possible but unusual1.5Weekly
5Even chance – could happen2.5Daily
8Probable – not surprised4Hourly
10Likely, only to be expected5Constantly
15Certain, no doubt

Degree of possible harm (DPH)Number of persons at risk (NP)
0.1Scratch or bruise11 – 2 persons
0.5Laceration, mild ill-health23 – 7 persons
1Break minor bone or illness (temporary)48 – 15 persons
2Break major bone or illness (permanent)816 – 50 persons
4Loss of 1 limb or eye/serious illness (temporary)1251 or more persons
8Loss of 2 limbs or eyes/serious illness (permanent)


Degree of Risk Evaluation

Risk IndexEvaluation
0 - 1Negligible
2 - 5Very Low
6 - 10Low
11 - 50Significant
51 - 100High
101 - 500Very High
501 - 1000Extreme
> 1001Unacceptable