Risk Definition and Classification

Table 1: Qualitative measures of likelihood or exposure to a hazard

Level	Descriptor	Description	Interval
A	Certain	The event is expected to occur in most circumstances	Daily
B	Likely	The event will probably occur in most circumstances	Bi-monthly
C	Possible	The event should occur at some time	Yearly
D	Unlikely	The event may occur at some time	Plant life
E	Rare	The event may occur only in exceptional circumstances	Ever

Table 2: Qualitative measures of consequence or impact

Level	Descriptor	Example of detail description
1	Insignificant	No injuries, no financial loss
2	Minor	First aid treatment, on-site release immediately contained, medium
3	Moderate	Medical treatment required, on-site release, contained with outside assistance, high financial loss
4	Major	Extensive injuries, loss of production capability, off-site release with no detrimental effects, major financial loss
5	Catastrophic	Death, toxic release off-site with detrimental effect, huge financial loss

Note: Measures used should reflect the needs and nature of the organisation and activity under study

Table 3: Qualitative risk analysis matrix – hazard priority

Likelihood	Consequence
	1	2	3	4	5
	Insignificant	Minor	Moderate	Major	Catastrophic
A Certain	High	High	Extreme	Extreme	Extreme
B Likely	Moderate	High	High	Extreme	Extreme
C Possible	Low	Moderate	High	Extreme	Extreme
D Unlikely	Low	Low	Moderate	High	Extreme
E Rare	Low	Low	Moderate	High	High

Note: The number of categories should reflect the needs of the study.

Legend:

Risk Level	Priority	Example of Action
Extreme	1	Detailed research and planning required, cease activity or task
High	2	Senior management attention, immediate corrective and preventative actions
Moderate	3	Corrective and preventative action plan, responsibility assigned
Low	4	Manage by routine procedure