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3  RISK ASSESSMENT AND SAFETY LEVEL
3.1  Risk Assessment
*1 SIL is standardized as an index showing the safety level. ( Page 21 SIL)
*2 SIL is standardized as an index showing the safety level. ( Page 22 PL)
*3 The risk is reduced by adding safety measures ( Page 20 Risk reduction).
Risk reduction
As a result of the risk assessment, when the machinery is judged as unsafe, the risk reduction must be performed by adding 
safety measures.
The measures for the risk reduction are standardized in ISO12100: 2010 as described below.
(For details, refer to ISO12100: 2010)
If ensuring the safety of machines by a single safe measure, combine and execute the multiple risk reduction measures until 
the machines are safe, according to the procedures above.
Item Description
Step 1 Risk reduction by inherently safe 
design measures
Inherently safe design measures eliminate hazards or reduce the associated risks by a 
suitable choice of design features of the machine itself and/or interaction between the exposed 
persons and the machine.
Step 2 Risk reduction by safeguarding and 
implementation of complementary 
protective measures
Taking into account the intended use and the reasonably foreseeable misuse, appropriately 
selected safeguarding and complementary protective measures can be used to reduce risk, 
when it is not practicable to eliminate a hazard, or reduce its associated risk sufficiently, using 
inherently safe design measures.
Step 3 Risk reduction by information for use Where risks remain despite inherently safe design measures, safeguarding and the adoption 
of complementary protective measures, the residual risks shall be identified in the information 
for use.