How to Reduce Risks

The risk reduction methods in ISO12100 are aimed at machine risk reduction. International standards call them "protection measures."
Implement this safeguard until the risk is acceptable.
Protective measures are implemented as follows in accordance with the concept called the 3-step method so that machinery and equipment can be made safer logically.

Flow of protection measures for risk reduction

3 step method

1. Essential safety design measures
2. Safety protection and additional protection measures
3. Usage information
We will promote the safety of machinery and equipment in three stages.

3-step method flow

STEP1. Intrinsic safety design measures

  • We review the structure of machinery and equipment to eliminate or reduce risks, such as eliminating hazards and limiting forces and speeds.

STEP2. Safeguarding

  • If reducing the risk through STEP 1’s intrinsic safety design is impossible or insufficient, the following safeguards will be taken.

    1. Spatial isolation

    Complete isolation of hazards by protective fences

    2.Temporal isolation (ensuring safety by stopping hazard sources)

    Install guard fences with interlocks

    ・ When the hazard can be stopped immediately
    Install a door interlock switch, etc.

    ・ If the source of danger cannot be stopped immediately
    Installation of door interlock switches with electromagnetic locks, etc.

    ・When detecting human intrusion into a dangerous area
    Installation of safety light curtains, etc.

    ・When detecting the presence of a person in a dangerous area
    Installation of safety laser scanners, etc.

STEP3. Usage information

  • If the risk cannot be completely removed or reduced (= residual risk), a warning label will be attached and a description will be given in the instruction manual.
    When implementing protective measures, if you select a protective measure based on control that attempts to ensure safety by stopping mechanical equipment by temporal isolation using door interlock devices, safety light curtains, safety laser scanners, etc. The control circuit that stops machinery must be designed according to the risk of the hazard that causes it to stop.
    This circuit is called the "safety-related part of the control system (SRP/CS)" and is designed based on the international standard ISO13849-1.