A systematic framework for risk assessment and risk reduction in machine design

When developing machines, it is not enough to focus solely on function and performance. The design must also comply with safety principles according to international standards. The most central is ISO 12100:2010, which serves as a framework for risk analysis and risk assessment throughout the machine’s lifecycle. 

In this article, we review the standard's methodology for risk reduction, how risks are classified, and the designer's role in the work with machine safety and CE marking. 

General Principles According to ISO 12100

The standard emphasizes that the risk assessment must consider: 

• The intended use of the machine and the reasonably foreseeable misuse. 

• All phases of the lifecycle: design, transport, installation, operation, maintenance, and decommissioning. 

• Human interaction at each stage. 

• Ergonomics and user-friendliness, including control interfaces. 

The process should be systematic, iterative, and well-defined. 

Three-Step Strategy for Risk Reduction 

ISO 12100 outlines a three-tier hierarchy, which must always be followed in order: 

1. Inherently Safe Design Measures

Here, risks should be eliminated at the source through design, for example by: 

• Minimizing stored energy

• Removing sharp edges 

• Restricting access to hazardous areas

2. Safeguarding and Complementary Safety Systems

When elimination through design is not possible, protection should be introduced, such as:

• Fixed or movable guards

• Emergency stops and safety switches

• Light curtains and presence sensors 

3. Information for Use

For remaining risks, clear information is required, such as: 

• Manuals and instructions

• Warning signs and labeling

• Recommendations for personal protective equipment 

• Training requirements

Risk Assessment Strategy

To conduct the risk assessment, ISO 12100 specifies the following steps: 

1. Define the machine's boundaries and use

2. Identify risk sources and hazardous situations

3. Estimate risk level (severity x probability) 

4. Assess if risk reduction is required

5. Implement measures according to the three-step model

6. Reassess remaining or new risks

The process is repeated until the risks are at an acceptable level. 

The Designer’s Responsibility in Risk Reduction

The designer plays a central role in implementing protection measures and communicating residual risks. 

This includes among other things: 

• Design changes and safety solutions

• Documentation of risk assessment and actions

• Technical files and user manuals 

Classification of Risks 

ISO 12100 contains a detailed list of hazards that can occur with machines. 

Some examples: 

• Mechanical: Clamping, entanglement, falling parts

• Electrical: Electric shocks, short circuits 

• Thermal: Burns from hot surfaces 

• Noise and Vibrations: Hearing damage, vibration injuries 

• Radiation: Laser, UV, or IR

• Chemical Substances: Toxic or corrosive substances

• Ergonomics: Poor working postures, repetitive movements

• Environmental Factors: Dust, humidity, extreme temperatures

• Combination Hazards: When multiple hazards interact 

This classification can be seen as a checklist that helps designers avoid missing important risks during development work. 

Conclusion

ISO 12100:2010 offers a clear and reusable method for: 

• Identifying and analyzing machine risks

• Reducing risks step-by-step through design, protection, and information

• Ensuring machines meet the requirements for CE marking.

By working according to the standard, companies can create machines that are not only efficient but also intrinsically safe and legally sustainable. 

Would you like to see how Noex can digitalize the entire process for risk assessment and CE marking?  Book a demo here!