Taking a closer look at ‘Safety Compliance’
04 May 2011
In the second article in his current series, Paul Davies turns his attention to ‘Safety Compliance’. Who lays down the rules? What are the rules? And what should you be doing to keep within them
As the industrial world gets smaller and production processes become increasingly integrated, adaptable and intelligent, safety compliance standards are required to maintain or improve safety, both at point the of production and at the point of use. It may seem to some that as soon as companies become accustomed to meeting certain safety criteria the goalposts are moved and a whole new set of regulations must be met. In truth global standards are becoming increasingly harmonised; making it easier and fairer to trade between countries and, above all, safer for those working in industry.
For companies that build a machine to work independently of any other- a ‘standalone machine’, compliance requirements are clearly defined and simply identified. However, for equipment or machinery that is built to work with other machinery, compliance is less straightforward. For many original equipment manufacturers (OEMs), end users, and systems integrators, the lines of responsibility for safety compliance can seem complex.
Machinery safety standards are governed by two global organisations: ISO and IEC. This is a good starting point for understanding the nature of the compliance issues that your company is required to meet as your local standards (European and/or National) are likely to help you to meet the relevant ISO or IEC standards. The IEC (International Electro-technical Commission) covers electro-technical issues and ISO (The International Organisation for Standardisation) covers all other issues. Most industrialised countries are members of IEC and ISO.
ISO is a non-governmental agency comprised of national standards bodies of over 150 countries around the world, thus local (European or National) standards relate directly to ISO standards; in fact, all new EN (European Norm) standards are aligned with, and in most cases have identical text with, ISO and IEC standards. In most countries standards can be regarded as voluntary, whereas regulations are legally mandatory. However, standards are usually used as the practical interpretation of the regulations. Therefore the worlds of standards and regulations are closely interlinked.
Beyond the machine itself there are further, much broader regulations to which compliance is non-optional, and in many cases must be proven. Essential Health & Safety Requirements (EHSRs) ensure that machinery is designed and constructed so that it can be used, adjusted and maintained throughout all phases of its life without putting people at risk. The Provision and Use of Work Equipment Regulations (PUWER) that pertain to machinery must also be met and maintained. PUWER regulations include the acquisition of equipment and the competencies of those responsible for testing it. It also offers guidance for the records that must be kept in relation to a machine.
For OEMs it is highly recommended to meet EN Harmonized European Standards as it is very problematic to prove conformity by other means. EN standards are the same for all EEA countries and are produced by the European Standardisation Organisations CEN and CENELEC. There are three types of standard: A, B and C.
Type A standards cover aspects applicable to all types of machines.
Type B are in two categories:
B1 standards for particular safety and ergonomic aspects of machinery.
B2 Standards for safety components and protective devices.
Type C standards are for specific types or groups of machines
In complying with the C Standard a presumption of conformity with the EHSRs is included; however, if the machine in question does not have a suitable Type C standard then conformity can be proven using Type A and Type B standards and indicating compliance with other relevant information in a ‘technical file’.
Technical files and proof of conformity
The person responsible for the conformity of any machine must have documentation that supports the claim. The technical file does not need to exist as a single file but it must be possible to assemble it in a reasonable amount of time if required to do so by an appropriate authority. It is also important to note that it must remain available for ten years after the production of the last unit.
The Supply of Machinery (Safety) Regulations 2008, Part 7 annex VII, 3, states that “Failure to present the technical file in response to a duly reasoned request by the competent national authorities may constitute sufficient grounds for doubting the conformity of the machinery in question with the essential health and safety requirements.” The exact contents required will be specific to the machine in question.
Certain types of machines are subject to different regulations as part of Annex IV of the Machinery Directive to which all machines used or for use within the EEC must adhere. Importantly Annex IV machines in conformity with Harmonised European Standards have to be shown to have followed the relevant procedure from three possible options. Such machines include presses, injection moulding machines, woodworking machines, underground equipment, vehicle servicing lifts and the like. Annex E also includes certain safety components such as light curtains and two-hand control units.
The three routes to conformity for Annex IV Machines are:
Send a copy of the technical file to a notified body that will acknowledge receipt (in this process the technical file will not be assessed unless there is a problem or a claim of noncompliance is made).
Send the technical file to a notified body who will verify that the Harmonized standards have been correctly applied and will issue a certificate of adequacy for the file.
Submit an example of the machinery to a notified body (test house) for EC type examination. If it passes, the machine will be given an EC type examination certificate. For Annex IV machines not conforming with a standard or where no relevant Harmonized European Standard exists, an example of the machinery must be submitted to a notified body (test facility) for EC type examination.
Systems integrators need to be aware of compliance issues from the perspective of both the OEM and the end user. Equipment that is intended for use in conjunction with another machine, or can be used in such a way, is now required to meet a level of safety appropriate to its final use. This means that only certain products are appropriate for certain processes and will meet the standards required for the machine to conform with regulations once the equipment has been integrated.
The SISTEMA software tool referred to in my first article 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 (a standard that will be covered in more detail in the next article of this series). The tool allows users to input their existing equipment and the software then models the control architecture and provides the user with the optional products to meet the required safety standard.
Paul Davies is field business leader – safety, sensing and connectivity, Rockwell Automation
Rockwell will be hosting a series of seminars to assist end users, integrators and machine manufacturers to develop a strategy that ensures their designs are compliant and meet the latest Directives, Regulations and Standards. The company has identified two main areas that will help to address the issues of compliance and give a greater understanding of roles and responsibilities’. The seminars (May through to November – various UK venues) will also include the fundamentals of EN ISO 13849-1 and a practical guide to using the SISTEMA tool. Check the website for details
What is a technical file likely to contain?
*Drawings detailing all of the equipment that makes up the machine including any control circuit drawings
*Calculations and detailed drawings that check conformity with the relevant EHSRs.
*Lists of relevant EHSRs, applicable Harmonised European Standards, all other applicable standards and technical design specifications.
*A description of measures taken and methods adopted to eliminate hazards presented by the machinery.
*If the machine is required to be certified by an approved body (test house) the certificate should also be included in the technical file.
*Similarly, if conformity is declared with a Harmonized European Standard any technical report giving test results for the machine should be included in the technical file.
*Full instructions for the operation of the machinery- in the case of series manufacture, details of internal measures such as quality systems to ensure that all machinery produced remains in conformity.
*Documentation detailing necessary tests or research carried out on components fittings or completed machinery to determine that whether by its design and construction it is capable of being erected and put into service safely.
*A copy of the EC declaration of conformity
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