Defeating of safeguards

Common causes of tampering are human and organisational factors such as time and production pressures, inadequate training or a lack of security structures. The absence of consequences provides a further incentive, but manufacturers of machines have only limited influence over this. However, the situation is different when it comes to technical causes.

Technical causes may include:

• Inadequate ergonomics
  • Access to controls or work areas is impeded by safeguards.
  • Access to controls or work areas is impeded by safeguards.
  • Protective covers restrict the view of the work process.
• Lack of user-friendliness
  • Protective systems are complicated or time-consuming to operate.
  • Frequent opening and closing of safeguards.
• Inflexible safety concepts
  • Special operating modes are not included in the safety concept.
  • Real work processes differ from the processes necessary for safe operation.

If the causes are not considered, the incentive to manipulate increases. These often lie in human behaviour. Convenience, the perceived need to increase efficiency or inadequate technical alternatives are further examples of incentives for manipulation.
 

Measures to prevent defeating

In order to effectively prevent defeating, manufacturers must take targeted measures. These measures include both organisational and product-specific solutions that aim to reduce incentives for defeating while ensuring the safety, usability and functionality of the machine.

Organisational measures

The manufacturer's service personnel have a special responsibility. Machines must not be tampered with during commissioning or maintenance under the watchful eye of the operator. Such behaviour would suggest to the operator's personnel that defeating is unavoidable in certain phases of the machinery life.

Furthermore, service personnel must recognise defeating and report it to the operator. The information collected must be forwarded to the design department so that the findings can be taken into account in the design. An organised exchange of information between the various departments of the manufacturer and the operator creates transparency.

Defeating also occurs because the safe option for handling or operation is not known. Training and user information can make an important contribution to the safe operation of the machine.

Product-specific measures

Preventing defeating
Measures that affect the product itself have the greatest impact. By incorporating potential incentives for defeating into the security concept and clever design, the risk can be significantly reduced. If possible, the possibility of defeating should be prevented from the outset. If this is not possible, measures must be implemented to make defeating more difficult and easier to detect.

Making defeating difficult
Defeating cannot be ruled out, even when the incentive is low. Safeguards must therefore be designed in such a way that defeating them requires a significant investment of time or material resources. Standards can provide important assistance here. For example, Chapter 8 of the standard EN ISO 14119:2025 describes measures to make tampering more difficult for interlocking, separating protective devices.

Detecting defeatingDepending on the safety function, it may be advisable to monitor its function and its position in relation to the process sequence. This can be implemented by the control system. The MR also specifies concrete requirements in Annex III 1.4.2 ‘Special requirements for guards’. For example, protective devices must not remain in their protective position after being released.

Operating instructions
The operating instructions play an important role in the safe operation of machines. Relevant content must be easy to find and written in a comprehensible manner, and must describe the safe use of the machines in all phases of their service life. This includes the correct application of protective measures.
 

Risk assessment as a key means of detection

For machine manufacturers, risk assessment is an indispensable tool for identifying defeating risks at an early stage and minimising them in a targeted manner. The protection concept against possible defeat must be an integral part of the design right from the initial phase of machine development. Retrofitting or adapting safety measures at a later stage is not only inefficient, but also carries considerable risks.

A key point is coordination with the future operating company. Ideally, its work tasks and requirements should already be documented in the specifications. If this information is not available or is incomplete, it is the manufacturer's responsibility to determine the relevant activities and define them within the technical and functional limits of the machine.

Once the protection concept has been developed, it must be checked whether the planned safeguards could potentially encourage tampering. Such incentives for tampering must not be ignored, as they provide valuable information for optimising the design. The aim is to reduce the motivation to circumvent safety precautions through technical and ergonomic improvements.

Ergonomic principles are essential in this regard. A user-friendly design increases the acceptance of safety functions and reduces the likelihood of tampering. In addition, safe and practicable options must be provided for detecting and eliminating foreseeable errors. This is another central component of an effective risk assessment.

For manufacturers, this means that risk assessment is much more than a legal obligation; it is a strategic tool for quality assurance, minimising liability risks and increasing operational safety.

DGUV Information 209-092 (Risk assessment of machinery – measures against the defeating of safeguards) is a helpful document that deals with this topic. The checklist in Annex 2 in particular can provide practical assistance.

The IFA (Institute for Occupational Safety and Health of the DGUV) also offers valuable information and practical assistance (IFA - Practical solutions: Prevent the defeating of safeguards). In addition, the institute has developed a web application for determining the incentive to defeat safeguards on machines.
 

Conclusion

Machine defeating remains an issue. Accident figures and the results of the DGVU survey confirm this. Machine manufacturers have many opportunities to identify existing defects and make their products better and safer. Proper organisation of communication and processes, including risk assessment, forms a good foundation.

Various practical aids such as checklists and information can provide valuable support. It is important that everyone involved is aware of their contribution to safety.