6.1 Safety integration and machinery risk assessment Flashcards
The Supply of Machinery (Safety) Regulations 2008 (SMSR) and the Provision and Use of Work Equipment Regulations 1998 (PUWER) originate from
Article 95 and Article 137 Directives respectively Article 95 DirectivesHarmonisation of productstandardsArticle 137 DirectivesWorking conditions
The aim should be to eliminate any risk throughout the foreseeable life cycle of the machinery, including transport, assembly, dismantling, disabling and scrapping. The following principles should be applied, in the order given: 3
(1) Eliminate or reduce risks as far as possible (inherently safe machinery design and construction). (2) Take the necessary protective measures in relation to risks that cannot be eliminated. (3) Inform users of the residual risks due to any shortcomings of the protective measures adopted, indicate whether any particular training is required and specify any need to provide personal protective equipment. Design danger out (inherently safe design) Design safety in (guards and protection devices) Protect end user from residual risks (IT IS / PPE)
The responsible person must ensure that a risk assessment is carried out in order to determine the health and safety requirements which apply to the machinery. The machinery must then be designed and constructed taking into account the results of the risk assessment. The risk assessment and risk reduction process should: 5
Determine the limits of the machinery, which include the intended use and any reasonably foreseeable misuse thereof. Identify the hazards that can be generated by the machinery and the associated hazardous situations. Estimate the risks, taking into account the severity of the possible injury or damage to health and the probability of its occurrence. Evaluate the risks, with a view to determining whether risk reduction is required, in accordance with the objective of the directive. Eliminate the hazards or reduce the risks associated with these hazards by application of the hierarchical approach specified in the principles of safety integration.
Establishing the limits of the machinery should take into account 4
Use Space Time Other
Risk is the combination of the probability of occurrence of harm and the severity of that harm, where the probability of occurrence of harm, is a function of: 3
(1) the exposure of person(s) to the hazard (2) the occurrence of a hazardous event (3) the technical and human possibilities of avoiding or limiting the harm.
The following aspects require careful consideration during risk estimation: 8
Persons exposed Type, frequency and duration of exposure Relationship between exposure and effects Human factors Reliability of safety functions Possibility to defeat or circumvent safety measures Ability to maintain safety measures Information for use.
Risks are reduced in accordance with the three stage hierarchical approach, discussed earlier as part of the principles of safety integration: 3
(1) Inherently safe design measures - the hazard is eliminated or the risk reduced by design or by the substitution through less hazardous materials and substances, or by application of ergonomic principles. (2) Risk reduction by the application of safeguarding and complementary protective measures, of a type that adequately reduces risk for the intended use and reasonably foreseeable misuse. (3) The provision of information for use to address any residual risk (operating procedures, safety information, training and PPE).
Adequate risk reduction is considered to be achieved when: 7
All operating conditions and all intervention procedures have been considered. The hazards have been eliminated or risks reduced to the lowest practicable level. Any new hazards introduced by the protective measures have been properly addressed. Users are sufficiently informed and warned about the residual risks. Protective measures are compatible with one another. Sufficient consideration has been given to the consequences that can arise from the use of a machine designed for professional/industrial use, when it is used in a non-professional/non-industrial context. The protective measures do not adversely affect the operator’s working conditions or the usability of the machine.
The CE marking requirements under the Machinery Directive relate to new machinery. However, if a machine is modified to such an extent that new hazards are anticipated, this will be considered a significant modification and the same measures will need to be taken as for new machinery. The process can be broken down into the following stages: 7
(1) Categorise the product. (2) Check the application of additional directives. (3) Ensure that requirements of safety regulations are met. (4) Perform the risk assessment. (5) Compile the technical file. (6) Issue the declaration of conformity. (7) Affix the CE mark.
With reference to European machinery standards, explain the meaning of the following categories of standard: Type A, Type B1, Type B2 and Type C AND give a practical example in EACH case. 10 marks
Type A standards are concerned with basic safety concepts and design criteria and apply to all machinery. Examples quoted could have included general safety requirements contained in EN ISO 12100 and the principles for risk assessment ISO 14121 (EN 1050). Type B standards relate to particular safety aspects in support of the general principles of the A standard. B1 standards for example refer to safety distances, such as in the design of fencing or the approach speed that is required for calculating the safety distance for safety light curtains or multiple light beam safety devices. B2 standards deal with the performance requirements of special protective devices, and contain notes on the design and testing of components or devices such as stop buttons, safety door switches, safety mats and safety light curtains. Type C standards describe specific risks and the measures for reducing these risks at specific machines or machine types. A relevant example would have been BS EN 693 concerned with hydraulic presses. A general point which should have been made was that if a C standard exists for a particular machine type, it takes priority over a B or A type standard. If, however, no C type standard exists for a machine being designed or manufactured, risk reduction in accordance with A and B standards should be made.
In relation to a newly designed machine that falls within Schedule 2 Part 4 Annex (iv) of the Supply of Machinery (Safety) Regulations 2008, outline the procedures that must be followed, and the requirements that must be met, before such a machine is placed on the market for sale in the European Economic Area. 10 marks
The machine designer/manufacturer should to ensure the machine satisfies the Essential Health and Safety Requirements (EHSRs), by reference to relevant EN standards, and should compile a technical file. If the machine is consequently found to be safe, and has been designed and manufactured according to EN standards, the manufacturer may either ensure that the machine is manufactured in accordance with the technical file by carrying out internal checks, or developing a quality assurance (QA) system and having it approved by an approval body, or obtaining EC type approval from an approval body. When any of these procedures is completed satisfactorily, the approved body issues either an EC type examination certificate or approval for the quality assurance system. If the machine is not designed and manufactured according to EN standards, the manufacturer may again either develop a QA system and have it approved, or obtain EC type approval from an approval body. A successful completion of either of the above will again result in the issue of an EC type examination certificate or approval for the QA system. Finally the manufacturer should ensure the machine conforms with other non-machinery directives before issuing a declaration of conformity and fixing the CE mark to the machine.
