Risk assessment according to ISO 12100:2010

What is a risk assessment?

The risk assessment is determined in accordance with the European Machinery Directive. The directive stipulates that the manufacturer of machines used in Europe must carry out a risk assessment before placing the machine on the market (ie its actual sale).

The term "Risk Assessment" is often used for a document that documents the outcome of a Risk Assessment in writing. But "Risk assessment", more specifically, is the process of determining what risks exist for the machine, how serious they are and what measures are taken to reduce the risk. It only applies to safety and accident risks for people who work on or near the machine or are in the machine's sphere of influence.

The main task of the risk assessment is to make the machine safe enough so that human life is not endangered during the life of the machine: from transportation to dismantling.

The EU Machinery Directive requires a risk assessment to be carried out and documented in writing. To market a machine in Europe and to comply with the law, it needs a "CE" mark. This marking - for machines - is not issued by an institution or a notified body, but the manufacturer can certify and issue a "CE" declaration. However, legal compliance requires, among other things, a risk assessment.

In what cases is a risk assessment necessary?

A risk assessment is required for all products covered by the EC Machinery Directive. These are all products with at least one moving part that is operated by anything (other than a direct human or animal) or intended to be operated by anything, such as a machine tool, a cordless screwdriver, or even, for example, a motorized garage door with a spring mechanism. There is also a list of other products that do not meet these characteristics but are covered by the Machinery Directive. In order to determine whether a product falls within the scope of the Machinery Directive (and thus requires a risk assessment), it is worth examining the scope of Article 1 of the Directive.

The Machinery Directive also distinguishes between complete and partially assembled machines. A semi-assembled machine is a unit or assembly intended to be incorporated into another machine (ie it cannot be used on its own). However, this is irrelevant to the question of whether a risk assessment is required, as a risk assessment is required in both cases.

How to prepare a risk assessment?

The criteria to be checked as part of the risk assessment are defined in the ISO 12100 standard, which also determines what content is required for the risk assessment documentation. The standard requires that a risk assessment be carried out during the design process. This is to ensure that the issue of safety is considered very early in the design process. This is because it is usually much more time-consuming and expensive to make changes the later you make them in the design and manufacturing processes.

Risk assessment is an iterative process where the first step is to identify the danger points. These can be, for example, hot surfaces, pinch points or the like. Hazard identification usually requires a lot of experience. There are also many standards covering different types of hazards that can help with identification.

The second step is risk assessment. This should take into account the seriousness of the possible damage, the probability of occurrence, the length of time spent in the dangerous area and the possibility of avoiding the danger. After the risk assessment, it can be determined whether measures to reduce the risk are necessary.

As a third step, determine one (or more) risk reduction measures in the following order:

1. Design measures for risk reduction.

The safest solution is to modify the design in such a way that the risk is completely eliminated. For example, the distance between two components can be increased so that the risk of crushing no longer exists.

2. Protective measures to reduce risk.

The second safest option is to provide a mechanical or electronic safety device (such as a safety fence or a limit switch that stops the motor when the door is opened).

3. Precautionary measures for risk reduction.

If it is not possible to create design or protective measures, then it is possible to create (ie write) a warning with instructions for people who work with the product. This warning can be placed as a sticker near the point of danger, or it can be included in the user manual.

Once the measures have been determined, the risk must be reassessed. If it is still not sufficiently reduced, further measures should be determined. Thus, a full assessment is carried out for each individual risk until the risk is reduced to an acceptable level.

Standards in the risk assessment process

Standards play an important role in risk assessment. Therefore, it is important to study the standards before starting the assessment.

Classification of standards:

  Type A standards(basic safety standards).
Provides basic concepts, design principles and general aspects that can be applied to machines;
Example of type A standards: EN ISO 12100 – General design principles

  Type B standards(general safety standards).
Refers to one aspect of safety or one type of safety measure that can be used on a wide range of machines;
Examples of B1 type standards:
EN ISO 13851 - Safety-related parts of control systems
DIN EN ISO 14120 – Arrangement of protective devices
Examples of B2 type standards:
EN 574 – Two-hand controls and
EN 953 – Fixed guards

  Type C standards(machinery safety standards).
Refers to detailed safety requirements for a specific machine or group of machines.
Examples of Type C standards:
EN ISO 16092-3 - Hydraulic presses
EN 415, 1-10 – Packaging equipment
EN 12409 – Thermoforming machines
Type C standards are specially developed for certain types of machines and define specific safety requirements for these machines. In principle, the authors of these Type C standards have carried out a general risk assessment for the specific machine type. This provides a good basis for risk assessment of your machine. However, the Type C standard does not replace a risk assessment. This is because the design itself may contain hazards that the standard authors could not have considered because they cannot know the specific design.

Harmonized standards.
The EU determines which standards create a presumption of conformity. If these agreed standards are met, the machine can be considered safe with a high degree of probability. Violation of these standards indicates that safety measures have not been followed.
The list of harmonized standards is published periodically in the Official Journal of the EU.

What does a risk assessment look like?

Neither the Machinery Directive nor ISO 12100 contain any formal requirements for demonstrating risk assessment. Thus, there are countless templates that can be used for risk assessment. However, it is important that the following elements are included:
• Product description
• List of applicable standards and regulations
• List of individual dangerous points with risks, assessment and risk reduction measures
• List of applicable and relevant health and safety requirements under the Machinery Directive

Who can prepare a risk assessment?

Each manufacturer is allowed to independently prepare a risk assessment. No special training is required by the Machinery Directive or market surveillance authorities. Anyone can prepare a Risk Assessment, but its quality preparation requires experience to be able to evaluate applicable standards, identify risks and find appropriate security measures.

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