The common sense of guarding standards

For the first time, the new Standard specifically refers to verification methods. These are outlined in Annex C, which covers guidelines for the selection of guards according to the number and location of hazards and provides a flow chart to assess the selection of guards according to the number and location of hazards. 

If there is a safety problem further down the line, and a machinery builder cannot demonstrate that they followed the very specific guidance in Annex C, it may suggest that due diligence has not been followed and legal action may be taken. 

Annex A in the old Standard now becomes Annex B (Guidelines for the selection of guards against hazards generated by moving parts) in EN ISO 14120. This provides a flow chart for the selection of guards against hazards generated by moving parts. In both standards, the flow chart asks: 'Is access required only for setting, process correction or maintenance?' In the old Standard the answer 'yes' would prompt the next question: 'Is access required more than once per shift?', while the new Standard simply asks: 'Is frequency of access high (more than once per month)?'

This has significant implications as a typical manufacturing day may include three shifts, each of which may require a different machine configuration, potentially more than 1095 alterations a year. However, the new Standard asks manufacturers to only consider if access is required more than 12 times per year, whereas the old standard was more focused on the frequency of individual shifts. 

In the previous Standard where access was required more than once per shift, a fixed guard, or a movable guard with interlocking device or without guard locking could be used. However, the new Standard only allows a fixed guard to be used if replacement and removal is easy. For machinery that is currently in production, this may require additional costs for part redesigns on new builds.

The new Standard also introduces the concept of ‘the foreseeable misuse and defeat of the guards’. This requires a machinery builder to consider more deeply how an operator could disable a guard or interfere with a machine in order that it continues to operate without guarding i.e. looking beyond the obvious intended use. A thoroughly documented risk assessment is therefore vital to not only highlight where guarding is required, but also how the machinery builder has considered that it may be defeated. 

Whereas the old Standard simply stated: 'Instructions shall be supplied for the correct installation of guards and associated equipment', the new Standard will make machinery builders think more deeply about how installation is approached, with specific requirements for fixing when guards are attached to a structure. 

The Standard now requires that consideration is given, but is not limited to:

•  Fixing to a floor

•  Assembling of movable guards

•  Number and types of fixings

•  Compliance with other relevant standards

The new Standard has also been expanded from requiring that: 'Information shall be provided indicating any actions to be taken before guards may be removed safely', to a more detailed list which includes requirements on the appropriate use of a tools. 

While the material changes to the new guarding standard are not significant, some elements are now more thoroughly detailed. This will help to make risk assessments less subjective as it leaves less room for interpretation by individual machine builders. However, while these changes may be considered common sense by those who already have solid due diligence procedures in place, the new Standard’s sections and annexes have been renumbered, necessitating a full update of any documentation for everyone.

TÜV SÜD Product Service is a global product testing and certification organisation.