The UK engineering industry could be on the brink of a safety crisis as confusion surrounds new electrical safety standards EN-62061 and ISO13849. Paul Hingley from Siemens Automation and Drives outlines the issues and potential consequences for those that fail to comply with the new regulations.
The focus on safety within the workplace has increased significantly within the engineering industry across the UK over the past 5 years. The demand for audit trails, written evidence and detailed health and safety procedures has become overwhelming for manufacturers and suppliers, at the same time machines are increasing in complexity and speed of operation.
Prior to March 2005 the protocol for monitoring and implementing safety systems, following the results of a risk assessment, lacked clarity and direction. Risk assessments could be carried out using a very basic form of assessment; however the questions contained non-specific terminology and consequently an inability to identify exact risks. Any requirement for a safety system, highlighted on the basis of the risk assessment would be specified with limited accuracy. For example if the majority of the products used within the system contained Category 4 (EN954-1) products and wiring, then the assumption would be that the system is Category 4. This, on most occasions is down to the interpretation of the specifications and production requirements from the end customer and the engineers involved in the design.
In March 2005 and December 2006 the Health and Safety Executive (HSE) accepted that the new engineering safety standards EN-62061 and ISO13849 respectively, as the way forward for safety standards here in the UK. These standards were designed to increase the transparency of integrated safety systems from production through to supply and to acknowledge the use of electronic safety devices that could now be implemented within complex systems. These new standards, for the first time, required documented proof that products from the many safety product suppliers actually achieved their stated level of protection and that when connected into a safety system containing more than one element; it continues to meet the requirements of the risk assessment.
Ambiguity based on people’s experiences and product definitions has led to the world of safety being seen as a ‘Black Art’ and feared by many engineers. However, it should be seen as standard to involve safety specialists in the complete design process of a project whether this is for a single machine or a complete process plant. People with in-depth knowledge can advise and validate every aspect of the initial and final stages to ensure clarity is maintained throughout the project.
The responsibility is now being placed on manufacturers, designers and suppliers to provide hard evidence and mathematical proof that health and safety procedures have been followed and are fully validated. As well as the requirement for a thorough risk assessment, there is now a demand for engineering documentation concerning the selection of products, implementation of the product and final validation of these products. Ultimately once installed, documentation is needed to prove that the overall integrity of the system is being maintained. This is a real engineering task that will ultimately have a commercial impact. This has to be recognised by UK industry and System Providers and must be allowed for in the scope of supply.
This type of approach has been applicable to some industries for many years. The Chemical Process and Nuclear industries have for some time now followed a well documented safety audit trail and are fully accustomed to providing such in-depth information as required when implementing IEC61511 and IEC61508. However there is a growing concern that despite expert resources such as safety seminars, there is still a considerable lack of knowledge by senior engineers within small to medium size companies regarding the new standards. The DTI and HSE have published guidance on this subject, but the extent to which engineers fully understand the changes and consequences of these new standards on the safety system design process is open to debate.
The new approach to machine safety will develop a quite complex trail of information and terminology. For example the chart below shows the two standards have different methods approach with regards to safety categorisation. For example the EN62061 uses the SIL (Safety Integrity Level) which is the same categorisation as used by the IEC61508 standard, while the ISO13849 uses PL (Performance Level). Ultimately, this could be confusing for the end users over time and therefore any debate concerning standard requirements must be addressed in the design stages.
Both standards now provide a differentiated perspective to the function, taking into account the quality of the product being used (failure rate) and the stress or loads that may be applicable to a particular product when in use.
The real issue is to raise awareness that there are changes taking place and the engineering industry as a whole needs to be more pro-active in determining their responsibilities. Dialogue between customers and manufacturers must be encouraged so that real choices can be made based on real information. By investing in new technology and systems that comply with these new standards we can begin to eradicate any possibility of the ‘Blame Culture’ in UK manufacturing and engineering that seems to have developed over the past few years. Clear documentation will be required and precise technical input will be an automatic part of the safety engineering process.
There is a perception within the industry that integrating a new compliant safety system is time consuming, costly and difficult to specify, this simply isn’t the case. Siemens for example ensure that all products are produced to provide a specific audit trail for end users and their labelling protocol allows suppliers and end users to calculate the exact SIL level. ProfiSafe and ASiSafe have for the first time brought standard logic control and safety control together on one distributed network while maintaining a high level of safety integrity. The Siemens range of Safety PLC’s is still expanding offering customers an even greater level of automation and safety control. Embracing new technology can result in lower engineering costs. Siemens fully integrate our products by using our unique TIA (Totally Integrated Automation) concept. By fully integrating the tools for implementation and validation within one operating and programming platform the customer can manage both automation and safety control. Consequently, automation and safety systems can be implanted at plant level with increased diagnostics for operational control and can be distributed to allow more installation flexibility.
The consequences of not complying with these new standards should encourage the engineering industry as a whole to take a more proactive stance in ensuring their risk assessment and safety protocols are in order. It will give companies the opportunity to predict and ring-fence safety costs, and so providing increased budget flexibility. A compliant safety system will from both a legal and moral standing, ensure that every possible machinery risk has been identified and dealt with, workers feel safer within their everyday environment and management have the benefit of accurate and constantly monitored data concerning the safety of their employees and protection of their capital investment. There will have to be decisions made over the coming weeks and months of how individual companies develop strategies of implementation to comply with this new legislation. Burying ones head in the sand will not be an option nor should it be when dealing with the potential loss of life or a potential serious injury. Whatever the reason for hesitation, clearly the industry must take a more proactive stance to avoid the development of a ‘blame culture’.