Safety: it’s more than just a hot topic
11 March 2011
In this, the first of an occasional series of four articles to be published in DPA during 2011, Paul Davies concentrates on three key areas of machine safety: compliance, deadlines for new safety standards and their impact on companies, and the technology of ‘Integrated Safety’
No company CEO would argue against the importance of providing a safe working environment for employees, yet many find it an area full of subtleties, complications and not without a fair smattering of confusion! Amid all the the uncertainty it becomes easy for commentators to obscure what the market has to offer with debate about the competing demands of maintaining competitiveness, while at the same time remaining compliant and safe. What should be borne in mind is the fact that the changing safety legislative environment is actually making it easier for companies to comply with the new standards and remain competitive.
In 2011, the three safety ‘hot topics’ for manufacturing industry are: compliance; the effects of new standards deadlines on business; and the competitive advantages that can be gained from Integrated Safety technology. These overlap in many areas and combine to form the core knowledge that can help companies achieve the seemingly difficult balance between compliance and productivity. In fact, those companies that are able to take a progressive attitude toward safety can expect to see improved productivity as a result.
It is important that standards which protect companies and, of course, the individuals that use their machines, are kept up-to-date. As control and safety become more integrated into machinery, so the nature of the machine changes, and the classification and regulations for machinery must be able to adapt to maintain safety standards. But back to the ‘hot topics’ referred to above. While each will be examined in more detail in future articles, I will use this first article to introduce them, albeit briefly!
Compliance is not simply about the change in legislation that will see the introduction of EN ISO 13849-1 at the end of this year, though changes detailed below will need to be incorporated to your overall compliance requirements. Other important steps to, and proofs of, compliance are prerequisite for machine builders and those manufacturers that build their own machinery.
End users, system integrators and machine builders are all required to meet various guidelines depending on their relationship to the machine in question. The Provision and Use of Work Equipment Regulations (PUWER), the Management of Health and Safety at Work Regulations (1992) and the Essential Health and Safety Requirements (EHSRs) under the new machinery directive all apply to a machine in different situations.
Machine builders must also ensure that they complete CE certification for any machine made for use or sale within the EEC. Inspecting, maintaining and re-inspecting equipment must be documented and various proofs of compliance produced upon demand.
The way different regulations overlap means that showing conformity to one set of regulations may cover other relevant regulations. In this regard the Central European Committee for Standardisation (CEN) and its electro-technical counterpart CENELEC advise that making equipment conform to a harmonised European Standard simplifies the task. These standards are not compulsory but strongly recommended, as seeking conformity by other means may be very complex.
It’s a common question - how will the deadline for conversion to new legislation EN ISO 13849-1 affect my company? Companies that are presently referencing EN 954-1 to show conformity to the design of safety-related control systems in the machinery safety sector must ensure that they reference the newer standards EN ISO 13849-1 or, for more advanced safety-control systems EN/IEC 62061, by December 31 2011. After this date, the European Machinery Directive will no longer reference EN 954-1 as a standard and hence this standard can no longer be used when completing a Declaration of Conformity.
There is a difference in the interpretation of what is defined as a safety related system on machinery in the new legislation, which results in a new way for companies to assess and report back on their equipment. For example, the ‘categories’ that were previously used to define safety related systems have been replaced by a more effective system of Performance Level (PL) and Safety Integrity Level (SIL). Many component manufacturers are supplying safety components that are compliant to the newer stated PL and SIL, and have been for some time. There is also an important independent tool that can help companies to understand which components are compatible with the necessary level of safety for their machines.
SISTEMA (Safety Integrity Software Tool for the Evaluation of Machine Applications) developed by Germany’s independent Institute for Social Accident Insurance research and testing (BGIA), helps to simplify calculation of the attained Performance Level of the safety related parts of a machine’s control system in the context of EN ISO 13849-1.
This tool allows users to input their existing equipment, whereupon it will model the control architecture and provide the user with product options to meet the required safety standard. There are many products available to select in the tool and these have been uploaded by component manufacturers. All have reached and been tested to a specific Level of Performance classification. My own company’s component library is featured within the SISTEMA tool.
Integrated Safety technology
For some time now, the technology of automation has been leading towards better integration and control, with improved diagnostics and management functionality. Such improvements help expand the potential of previously discrete, individual machines such that they become more adaptable and thus more productive. Today, machines are expected to perform an increasing variety of tasks, moving between these tasks often with just a flick of a switch. Taking instruction from ‘intelligent’ control systems, machines are able to adapt in real-time to pre-set values or management decisions.
This means that ‘safety’ in terms of modern automation has to be addressed in a more flexible, dynamic environment, and the best way of achieving this is to integrate safety into the processes that the machine is expected to complete – in other words, to design it into the machine. This is the way Integrated Safety works; the compliance environment has changed in recent years to reflect this, as well as preparing for the integration of future technologies that will introduce greater flexibility of safety systems implementation.
Time is now running out for those companies that still reference EN 954-1 and have yet to assess their machines in relation to the new standards. There are tools and guides that can help - SISTEMA being prominent among them – as well as reputable partners with relevant expertise who can help you achieve compliance and improve efficiency and productivity. My own company is finding that far from considering this process a troubling expense, many of our clients are able to improve productivity using Integrated Safety technology that conforms to the new standards and all compliance expectations.
Paul Davies is field business leader, safety, sensing and connectivity, at Rockwell Automation