The European Standard EN ISO 14121-1 puts forward a systematic procedure for the examination of the hazards associated with machinery with the aim of selecting and adopting the most suitable safety measures to reduce or eliminate the risks.

For USA an equivalent procedure is described in the ANSI Technical Report B11.TR3.

The risk assessment can thus be broken down into 4 stages:

1. Determination of the limits of the machine
Consists in the examining of the intended use and of all the reasonably foreseeable misuses in relation to the level of training, experience and attitude of the user.

2. Identification of the hazards
Consists in the listing of:
• The risks and the hazardous elements (mechanical, electrical, chemical, etc.)
• Hazardous situations (manual loading-unloading, access to the system, etc.)
• Events that might cause damages (machine failures or anomalies).

During all phases of the machine life cycle up to the decommissioning and dismantling.

3. Risk estimation
Each hazardous situation identified is derived from a combination of the following elements:
• Severity of injuries or damage to health (reversible, irreversible, fatal)
• Probability of occurrence of that injury, which is a function of frequency and duration of exposure to danger
• Possibility of avoiding danger with reference to:
- rapidity of occurrence of the event,
- possibility by the operator to perceive hazards and react promptly,
- possibility to escape.

4. Risk evaluation
Following the risk estimation a risk evaluation is required to determine if a risk reduction is necessary or whether safety has been achieved. If risk reduction is required, the protective measures selected and applied shall be evaluated to determine if an adequate risk reduction has been achieved.