G.2 Process Risk Assessment
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Fig. G.2 Risk matrix for the release of HCN in the work-up reaction of 3-amino-2-isopropylthio
benzonitrile
G.2.4 Step 5: Risk Evaluation
As determined in the previous section and shown in Fig. G.2, the risk for people
at the neighboring site is acceptable (below the acceptability line). However for
operators at the plant, the risk level is not acceptable, and additional safety measures
need to be implemented in order to reduce the risk to an acceptable level.
G.2.5 Step 6: Risk Management
(a)
• Make use of an emergency power aggregate for all critical process equipment
and an emergency cooling unit.
• Different safety mechanisms should not be coupled to the same power source,
but instead have independent emergency power sources.
• Ensure periodic maintenance of the reactor, measurement devices, and
alarms. Have an inspection and maintenance plan.
• Install permanent monitoring of workplace air for HCN and H 2 S levels with
a connected alarm.
• Have personal protection equipment ready in case of an accidental release
and for any sampling exercise where exposure could occur.
• Create an emergency plan and complete regular safety training with operators.