A brief overview of European Safety Standards.
European Machinery Directive & CE Marking
The European standard EN ISO 13849-1 represents a major change in the philosophy of designing and implementing safety-related parts of machine control systems. It is a movement from the sole reliance on the proven-in-use deterministic approach of standards such as EN 954-1, to include probabilistic considerations.
The new standard uses risk assessment to determine a required Performance Level (PLr). Achievement of the Performance Level is based on four aspects:
Control Reliability of circuit architecture.
Mean Time to Dangerous Failure (MTTFd).
Reduction of Common Cause Failures.
The drafters of EN ISO 13 849-1 strived to achieve a delicate balance between deterministic and probabilistic thinking. The European manufacturing community is currently in transition to this new standard, which will soon replace EN945-1 as the benchmark for risk assessment and safety compliance.
Specific Background Information on EN ISO 13 849-1:2006 is a comprehensive guide to this new standard.
The European safety requirements for man and machine are established in the European Machinery Directive (EMD). According to the EMD, machinery must be designed and built to meet the Directive’s requirements as defined by existing and emerging European standards. These “European Norms”, prepared by representatives of the European Economic Community (EEC) member states and produced by the European standards committees CEN and CENELEC, provide a harmonized baseline for the design and construction of safe machinery.
As of January 1, 1997, machinery sold into or within the EEC must comply with the requirements of the European Machinery Directive. Equipment which complies may be affixed with the CE mark (for “Conformité Europeene”). The CE mark on a machine signifies that it conforms to the essential health and safety requirements defined by the relevant European Norms.
These “Norms” form a hierarchical structure which include:
Type A Standards:
Fundamental Safety Standards which contain basic concepts, principles of design, and general aspects applicable to all machinery.
Type B Standards:
Group Safety Standards, each of which focuses on a specific subject applicable to a range of machinery types. “B1 Standards” cover a specific safety aspect defined in the Fundamental Standards. “B2 Standards” cover the requirements of specific safety related devices such as two-hand controls, interlocking devices, movable guards, etc.
Type C Standards:
Specific Machine Safety Standards, each of which define protective measures required for hazardous areas of a specific machine or group of machines.
Type A and Type B Standards are intended to assist in the machinery design process, and eliminate the need to repeat these general requirements in the machine specific (Type C) Standards.
Many product standards are still in the planning stage and the number of Type C Standards is continuously increasing. Some are still in draft form (designated as “prEN” standards). Others exist as finished (“EN”) standards.
Where no machine-specific standard exists, the requirements of the Machinery Directive can be satisfied by observing existing European Standards and relevant national standards or specifications. Draft standards (prEN) published by the European Union are also accepted and used as a basis for evaluating products for compliance to the Directives. It is important to note that such draft standards may change before being finalized and adopted as EN standards.
SELECTED EUROPEAN STANDARDS
Type “A” Standards:
EN ISO 12100, Safety Machinery – Basic Concepts, General Principles of Design, Parts 1 & 2.
Type “B1” Standards:
EN ISO 13849-1 Safety of Machinery – Safety-Related Parts of Control Systems – Part 1: General Principles for Design
EN ISO 13857 Safety of Machinery – Safety Distances to Prevent Danger Zones from Being Reached by Upper and Lower Limbs.
EN349 Safety of Machinery – Minimum Gaps to Avoid Crushing of Parts of the Human Body.
EN ISO 13855 Safety of Machinery – The Positioning of Protective Equipment in Respect of Approach Speeds of the Human Body.
EN ISO 12100 Safety of Machinery – Principles of Risk Assessment.
Type “B2” Standards:
EN ISO 13850 Safety of Machinery – Emergency Stop Devices, Functional Aspects – Principles for Design.
EN 574 Safety of Machinery – Two-Hand Control Devices, Functional Aspects – Principles for Design.
EN1088 Safety of Machinery – Interlocking Devices Associated with Guards – Principles for Design &
EN 953 Safety of Machinery – General Requirements for the Design and Construction of Guards.
EN1760-1 Safety of Machinery – Pressure Sensitive Safety Devices – Mats & Floors.
EN1760-2 Safety of Machinery – Pressure Sensitive Safety Devices – Edges & Bars.
EN ISO 14119:2013 Safety of Machinery - Interlocking devices associated with guards — Principles for design and selection
EN 61496 Safety of Machinery – Electro-sensitive Protective Equipment.
Type “C” Standards:
EN415 Packaging Machines
EN692 Mechanical Presses
EN693 Hydraulic Presses
EN746 Thermoprocessing Machines
EN931 Footwear Manufacturing Machines
EN1114-1 Rubber & Plastics Machines
EN1672 Food Processing Machines