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Rockwell Automation Publication IASIMP-QS005H-EN-P - April 2016
Chapter 1
Risk Assessment and System Design
Select Mitigation Techniques for Hazard Control
These basic methods should be considered and applied in the order shown.
1. Eliminate or reduce the risks as far as possible using inherently safe machine design and construction.
2. Install the necessary protective systems and measures in relation to risks that cannot be eliminated by design.
3. Implement the administrative, awareness means, Personal Protective Equipment (PPE), and training
requirements.
4. Inform the affected personnel of the controlled and residual risks after the mitigation techniques have been
implemented. Indicate whether any additional training is required and specify any need to provide PPE.
Each measure from the hierarchy should be considered starting from the top and used where possible. This usually results
in a combination of measures.
Incorporate Protective Systems and Measures
If access to a hazardous area is not required, the solution may be to safeguard it within the body of the machine or by
some type of fixed enclosing guard. If access is required, it is necessary to make sure that access can only be gained while
the machine is in a safe state. Protective measures such as interlocked guard doors or trip systems may be required. The
choice of protective devices or systems should be heavily influenced by the operating characteristics of the machine. The
safety of the operator depends on the proper application and correct operation of the protective system even under fault
conditions.
A safety-related system may contain many elements, including the protective device, wiring, power switching device, and
sometimes parts of the machine’s operational control system. All these elements of the safety system should have suitable
performance characteristics relevant to their design principles, technology and safety functional requirements.