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Control of Industrial Major Accident Hazards (CIMAH) Report Page 6
Ranhill SAJ Sdn. Bhd. Revision 01
Part D: Information on the Potential Major Accident Date Aug 2019

Fire incidents produce thermal radiation due to heat wave; explosion incidents
produce blast/shock wave and potential projectile/missile; and toxic release incidents
produce acute health effect such as Immediate Danger to Life and Health (IDLH).

The consequence of the event is modelled and mapped on the plant layout and
terrain by using the physical effects modelling software. This software provides
visual effect of the consequence contour on the plant and surrounding population.

The consequence of an event that leads to significant safety and health impact on
people (i.e. individual risk per year) are calculated based on the “number of fatality
per person per year”. Various methods of calculation are being used in the practice
of quantitative risk assessment such as vulnerability model, probit analysis, etc.

This individual risk is very much location dependent and is plotted on a geographical
map in the form of iso-risk contours.

The quantified risk is compared to the legislative or industrial risk acceptance criteria.
For Malaysia, the Department of Environment (DOE) has established the risk
acceptability criteria for involuntary risks for industry activity (e.g. process and
chemical industry).

The risk acceptability criteria for industrial facility is described as follows:
-5
• Not exceeding 1 x 10 fatalities per person per year at nearby industrial
areas.
-6
• Not exceeding 1 x 10 fatalities per person per year at nearby residential
areas.

1 x 10 -3

-4
1 x 10
Within Plant 1 x 10 -5

-6
Offsite Plant 1 x 10

-7
1 x 10
-8
1 x 10