Machinery Safety Presented by Paul Laidler
Machinery Division Safety Solutions Assistance in meeting the requirements of machinery safety legislation Machinery, Low Voltage and Electro Magnetic Compatibility (EMC) Directives Work Equipment Directive PUWER and LOLER Comprehensive risk assessments Guidance on technical file construction and declaration of conformity/incorporation Pre-purchasing CE Audits Safety Related Control System validation
Machinery Safety Engineering Services Engineering design Site survey and function design specification Factory acceptance test Installation and commissioning Machine guarding Design, manufacture and installation of machine guarding and Safety Related Control Systems Solutions include perimeter guarding, light curtains, scanners, interlocking etc.
HSE Horse
Legislation Machinery Directive 2006/42/EC
Machinery Directive EHSR s 1.3.7 Risks related to moving parts The moving parts of machinery must be designed and constructed in such a way as to prevent risks of contact which could lead to accidents or must, where risks persist, be fitted with guards or protective devices. 1.3.8 Choice of protection against risks arising from moving parts Guards or protective devices designed to protect against risks arising from moving parts must be selected on the basis of the type of risk.
Machinery Directive EHSR s 1.4.1 General requirements Guards and protective devices must: be of robust construction, be securely held in place, not give rise to any additional hazard, not be easy to by-pass or render non-operational, be located at an adequate distance from the danger zone, cause minimum obstruction to the view of the production process,
Machinery Directive EHSR s 1.4.1 General requirements cont Guards and protective devices must: enable essential work to be carried out on the installation and/or replacement of tools and for maintenance purposes by restricting access exclusively to the area where the work has to be done, if possible without the guard having to be removed or the protective device having to be disabled. In addition, guards must, where possible, protect against the ejection or falling of materials or objects and against emissions generated by the machinery.
Machinery Directive EHSR s 1.4.2.1 Fixed guards Fixed guards must be fixed by systems that can be opened or removed only with tools. Their fixing systems must remain attached to the guards or to the machinery when the guards are removed. Where possible, guards must be incapable of remaining in place without their fixings.
Machinery Directive EHSR s 1.4.2.2 Interlocking movable guards must as far as possible remain attached to the machinery when open, be designed and constructed in such a way that they can be adjusted only by means of an intentional action. Interlocking movable guards must be associated with an interlocking device that: prevents the start of hazardous machinery functions until they are closed and gives a stop command whenever they are no longer closed.
Machinery Directive EHSR s 1.4.2.2 Interlocking movable guards (cont) must Interlocking movable guards must be designed in such a way that the absence or failure of one of their components prevents starting or stops the hazardous machinery functions.
Machinery Directive EHSR s 1.6.4 Operator intervention Machinery must be so designed, constructed and equipped that the need for operator intervention is limited. If operator intervention cannot be avoided, it must be possible to carry it out easily and safely.
Definition of a Safety Component Definition of a Safety Components Which serves to fulfil a safety function, which is independently placed on the market, the failure and/or malfunction of which endangers the safety of persons.
Definition of a Safety Component Safety devices that fall under the scope of the Directive Annex V Indicative list: Extraction systems. Guards and protection devices. Control devices for calling lifting appliances and anti fall devices for hoists. Protective devices designed to detect the presence of a person. Safety belts and seat harnesses. Hydraulic non return valves where they are used to prevent falls.
Legislation Provision and Use of Work Equipment Regulations 1998
PUWER 98 Regulations Regulation 5 Maintenance (1) Every employer shall ensure that work equipment is maintained in an efficient state, in efficient working order and in good repair. (2) Every employer shall ensure that where any machinery has a maintenance log, the log is kept up to date.
PUWER 98 Regulations Regulation 11 Dangerous parts of machinery (1) Every employer shall ensure that measures are taken in accordance with paragraph (2) which are effective (a) to prevent access to any dangerous part of machinery or to any rotating stock-bar; or (b) to stop the movement of any dangerous part of machinery or rotating stock-bar before any part of a person enters a danger zone.
PUWER 98 Regulations Regulation 11 Dangerous parts of machinery (2) The measures required by paragraph (1) shall consist of (a) the provision of fixed guards enclosing every dangerous part or rotating stock-bar where and to the extent that it is practicable to do so, but where or to the extent that it is not, then (b) the provision of other guards or protection devices where and to the extent that it is practicable to do so, but where or to the extent that it is not, then
PUWER 98 Regulations Regulation 11 Dangerous parts of machinery (b) be of good construction, sound material and adequate strength; (c) be maintained in an efficient state, in efficient working order and in good repair; (d) not give rise to any increased risk to health or safety; (e) not be easily bypassed or disabled; (f) be situated at sufficient distance from the danger zone;
PUWER 98 Regulations Appendix II Explanation of safeguarding terms, regulation 11(2) GUARDS are physical barriers which prevent access to the danger zone. FIXED GUARDS in regulation 11(2)(b) have no moving parts and are fastened in a constant position relative to the danger zone (see Figure 1). They are kept in place either permanently, by welding for example, or by means of fasteners (screws, nuts etc) making removal/opening impossible without using tools.
PUWER 98 Regulations Appendix II Explanation of safeguarding terms, regulation 11(2) If by themselves, or in conjunction with the structure of the equipment, they ENCLOSE the dangerous parts, fixed guards meet the requirements of the first level of the hierarchy. Note that fixed enclosing guards, and other types of guard, can have openings provided that they comply with appropriate safe reach distances (see BS EN 13857).
PUWER 98 Regulations Appendix II OTHER GUARDS in regulation 11(2)(b) include movable guards which can be opened without the use of tools, and fixed guards that are not fully enclosing. These allow limited access through openings, gates etc for feeding materials, making adjustments, cleaning etc (see Figure 2). MOVABLE GUARDS may be power-operated, selfclosing, adjustable etc and are likely to require an interlocking device so that:
PUWER 98 Regulations Appendix II (a) the hazardous machine functions covered by the guard cannot operate until the guard is closed; (b) if the guard is opened while hazardous machine functions are operating, a stop instruction is given; (c) when the guard is closed, the hazardous machine functions covered by the guard can operate, but the closure of the guard does not by itself initiate their operation.
PUWER 98 Regulations Appendix II Adequate INFORMATION, INSTRUCTION, TRAINING AND SUPERVISION are always important, even if the hazard is protected by hardware measures, however, they are especially important when the risk cannot be adequately eliminated by the hardware measures in regulation 11(2)(a) to (c). It may be necessary to lay down procedures to define what information, instruction, training and supervision must be given, and to restrict use of the equipment to those who have received such instructions etc.
Hierarchy Of Control Control Measures Design the hazard out. Remove the need for man machine interface. Design in safeguards. Reduce the possibility of occurrence. Reduce the degree of harm. Warn and inform (but only if you can achieve adequate safety)..
Use of Standards
The Role of EN Standards Can be used to demonstrate conformance with regulations. Approved Codes of Practice refer to EN standards CE Marking Guidance refers to EN Standards
The Role of EN Standards Machinery manufactured in conformity with specified published European Harmonised standards will be presumed to comply with the Essential Health and Safety Requirements covered by those standards
Now that s what I call a hedge trimmer!
Risk Assessment (BS EN 12100:2010) Risk assessment must be carried out to Determine the limits of the Machinery Identify Hazards Estimate Risk and Evaluate Adequate Risk Reduction Design out hazard Reduce risk, lower power, speed etc Guard or protect Information and Warnings Re-assess and evaluate until acceptable
Risk Assessment (BS EN 12100:2010) Risk Reduction must consider Stability Maintainability Ergonomic Principles Electrical Hazards BS EN 60204-1 Hydraulic Hazards BS EN 4413 Pneumatic Hazards BS EN 4414 Safety related control systems BS EN 13849/62061 Electro Magnetic Compatibility (unexpected start)
Risk Assessment Mechanical risk reduction involves removing or reducing to a minimum trap, nip or pinch points.
Risk Assessment To reduce risks from debris and ejected parts
Safety Related Control System A protection device or interlocking system should be designed so that it will only operate as intended. Furthermore, if a component deteriorates or fails, the device or system should as far as possible fail in a safe manner by inhibiting the dangerous action of the machine.
EN 13849
Types of EN Standard A type apply to all machines B type are designed to promote safety and split into B1 and B2 C type apply to a specific type of machine
Types of EN Standard BS EN 12100-2010 Safety of machinery, general principles for design and risk assessment. BS EN 414 Safety of machinery Rules for drafting and Presentation of safety standards IEC 60204-1 Electrical Equipment BS EN ISO 13857 Upper and Lower limb access. BS PR ISO EN 13850 418 Emergency Stop SPECIFIC PROTECTIVE DEVICE STANDARDS 2 Hand Controls Light Curtains Safety Switches etc TYPE C STANDARDS for Machines
Types of EN Standard Type A Standards Applies to all machinery and are essential reading for machinery builders and modifiers BS EN 12100:2010 Safety of Machinery General principles for design Risk assessment and risk reduction (ISO 12100:2010)
Types of EN Standard 'B1' Standards Apply to all machinery and are designed to promote the essential factors mentioned in the foreword. 'B2' Standards These are "apply when used" Standards, i.e. if a particular safety device is chosen for a machine, then it must, be manufactured to the relevant standard. E. g. Interlock switch, E stop switch.
Types of EN Standard Type B Standards BS EN ISO 13850 Emergency stops BS EN ISO 13855 Relates to the positioning of Electro-sensitive protection devices. (light curtains, pressure mats etc). BS EN 953 Safety of Machinery - Guards BS EN 1088 Interlocking devices associated with guards BS EN 4413 Hydraulic systems. BS EN 4414 Pneumatic systems. BS EN ISO 13732-1 Hot surfaces
Types of EN Standard Type C Standards BS EN 415 Series Safety of Packaging Machines BS EN 10218 Industrial Robots Recommendations for Safety. Parts 1 & 2. BS EN 12417 Safety of Machine tools Machining Centres. BS EN 692 Mechanical Presses
BS EN ISO 13857 Scope This International Standard establishes values for safety distances in both industrial and non-industrial environments to prevent machinery hazard zones being reached. The safety distances are appropriate for protective structures. It also gives information about distances to impede free access by the lower limbs.
BS EN ISO 13857 Use of Tables Reaching over protective structures: Table 1 shall be used where there is a Low Risk Table 2 shall be used where there is a High Risk.
BS EN ISO 13857
BS EN ISO 13857
BS EN ISO 13857
BS EN ISO 13857
BS EN 349 This standard enables users to avoid hazards from crushing zones. It specifies minimum gaps relative to parts the human body.
BS EN 349
BS EN 953 SCOPE This standard specifies general requirements for the design and construction of guards provided to protect persons from mechanical hazards.
BS EN 953 Risk assessment In order to select and design types of guards appropriate to particular machinery, it is important to assess the risk arising from the various hazards present at that machinery and the foreseeable categories of persons at risk! see EN ISO 12100
BS EN 953 To minimise access to danger zones where practicable, guards and machinery shall be so designed as to enable routine adjustments, lubrication and maintenance to be carried out without opening or removing the guards. Where access is required within the guarded area this shall be as free and unobstructed as practicable. Loading, unloading, setting, maintenance, jam clearance, lubrication etc.
Enclosing Fixed Guard
BS EN 953 Guards are used for numerous reasons including. Containment of ejected parts Containment of hazardous substances Noise reduction Radiation containment Explosion (blast panels designed to dissipate force) Viewing of process
Distance Guarding - Fixed
BS EN 953 Guards must be suitable for purpose. Must be able to handle guards safely, not too heavy, unstable, have handles if hard to lift. Movable guards or removable sections of guards shall be designed to permit ease of operation. Guards shall be designed so far as is practicable to take into account foreseeable use and reasonably foreseeable misuse. Guards shall be designed so as not to cause hazardous crushing or trapping points, with parts of the machine or of other guards.
Combination of Guards & Protective Devices
BS EN 953 Guards must be suitable for purpose. Guards shall be constructed so as not to have exposed sharp edges and corners or other hazardous projections. Guards shall be designed to withstand reasonably foreseeable impacts from parts of machinery, workpiece, broken tooling, ejected solid or fluid matter, impact by the operator, etc. Materials and finishes used shall be non-toxic in all foreseeable conditions of use.
Distance Tunnel Guard
BS EN 953 Selection of guards Guards should be selected from the following in the order of priority given: a) Local guards enclosing individual danger zones if the number of danger zones to protect is low. This can provide an acceptable residual risk and permits access to non-hazardous machine parts for maintenance, setting, etc. b) A guard enclosing all the danger zones if the number or size of the danger zones is high. In this case setting and maintenance points should, as far as possible be located outside the guarded area.
BS EN 953 Selection of guards Guards should be selected from the following in the order of priority given: c) Partial distance guard if the use of an enclosing guard is impracticable and the number of danger zones to protect is low. d) Fully surrounding distance guard if the use of an enclosing guard is impracticable and the number or size of the danger zones are high.
Suitability of guards
BS EN 953 Climbing on guards shall as far as practicable be inhibited by design. Consideration shall be given to this possibility in their construction and the selection of materials and shapes. By eliminating horizontal structural members and the horizontal component of mesh fabric from the outside surface of the guard, climbing is made more difficult.
BS EN 953 Colour Hazards can be highlighted by the use of suitable colours. For example if a guard is painted the same colour as the machine and the hazardous parts painted a contrasting bright colour, attention is drawn to the hazard when the guard is opened or left off.
END Tel. +44 (0) 1642 345637 Fax +44 (0) 1642 345643 E-Mail: paul.laidler@tuv-sud.co.uk www.tuv-sud.co.uk