This safety guide refers to the set of rules governing the control system on safety of machinery. In particular, this concerns the crucial family of standards under the umbrella of:
- ISO 13849 “Safety of machinery” (ISO)
- IEC 61508 “ Functional safety of electrical / electronic / programmable electronic safety related systems” (IEC). IEC 61508 impacts safety of machinery especially through IEC 62061 “Safety of machinery – Functional safety of safety-related electrical, electronic and programmable electronic control systems”
- IEC 61496 “Safety of machinery – Electro sensitive protective equipment”
Important statistical concepts related, in varying degrees, to probability of dangerous failure, are covered by machine safety, resulting in new classifications of safety-related control systems for machinery and protection devices. These include PLs (Performance Levels, for ISO) and SILs (Safety Integrity Levels, for IEC). PL and SIL come next to and in many ways replace the now familiar concept of Category featuring in the ‘old’ EN 954-1.
The second edition of the Technical Specification IEC TS 62046 “Application of protective devices for the detection of the person”, is a useful guide for users who want to use protective devices for the realization of control systems for machine safety.
The aim of the EC Directives is to harmonize the national legislation of the Member States so as to have common regulations concerning technical, economic, social aspects, etc. and to facilitate the free circulation of goods, service and people within the European Union.
In particular, where the safety of workers is concerned, the harmonization of legal provisions has resulted in the formulation and approval of Directives and Standards of great importance.
Define the objectives to be achieved.
Define the means and methods by which to achieve the objectives established by the Directives.
A product/service that complies with the harmonized Standards is presumed to conform to the Directives.
Stages for the realization of a Standard:
- Creation of a Working Group (WG) made by experts of the subject to be treated, which represents the Member States
- Preparation of a draft version of the Standard (prEN) to be examined by the various national Committees involved, for comments, proposals and the subsequent final approval
- Drafting of the definitive formulation of the text of the Standard (EN), official publication, and acceptance by the individual Member States
The Directives concerning the protection of workers are:
- 89/391/EC “Health and safety at work – Framework directive”
- 2009/104/EC “Use of work equipment” and amendments / additions
The Directives governing safety components are:
- 2006/42/EC “Machinery directive”
- 2006/35/UE “Low Voltage Directive”
- 2014/34/EU “Electromagnetic Compatibility Directive”
- 2014/34/UE “ATEX directive”
“Social Directives” 89/655/EC and 89/391/EC, are aimed at the improvement of safety in working environment.
- Determine the preventive measures to be adopted in the working environment.
- Supply information on:
- risk analysis
- program of prevention and achievement of compliance of the machines
- procedures concerning the compliance of machines
- responsibilities of the employer
- education and training of the people in charge of system operation
- Imposes the adaptation of existing machinery in compliance with the provisions of the Machinery Directive
THE MACHINERY DIRECTIVE
The “Machinery Directive” 2006/42/EC, is meant for the manufacturers of machines and safety components, and has the following objectives:
- The definition of safety and health protection requirements for the improvement of the degree of protection offered to the operators of hazardous machinery
- The design, construction and marketing in the European Union of safety machines and components complying with the minimum safety requirements laid down by the Directive itself
- The free circulation in the Member States of machines and safety components complying with the Directive
The Machinery Directive
- It applies to all new machines and safety components that are sold, lent or hired, and to used machinery in the event of sale, rental or loan
- It sets forth the essential safety requirements relating to the design and construction of machines and safety components and it defines the respective certification procedures
- It is mandatory for machines and for safety components. Only products conforming to the Directive can be marketed or commissioned in the European Union
- Lays down stringent procedures for safety components and highly hazardous machines which are listed in annex 4.
- Lays down simplified procedures for low and medium risk machines not included in annex 4.
- Requires that manufacturers prepare a technical dossier for each product stating the safety principles adopted in the design, manufacture, transport, use and maintenance of the machine or the safety component.
Declaration of conformity
In order to certify the conformity of a product to the Directive, the manufacturer must:
- Affix the CE mark to the product
- Attach the CE declaration of conformity attesting compliance to the Directive
The CE type certificates is valid for 5 years (Annex IX para. 9.3), the five-year period starting from the revision date of the certificate. After which a new verification will be required to maintain the certification.
LOW VOLTAGE DIRECTIVE
2014/35/EU is aimed at ensuring that electrical materials are designed and manufactured so as to guarantee the protection of people against any risk of injury arising from the use of such materials.
This Directive applies to all electrical materials meant for use at a nominal voltage of between:
- 50V and 1000V for alternating current
- 75V and 1500V for direct current
ELECTROMAGNETIC COMPATIBILITY DIRECTIVE
The aim of “Electromagnetic Compatibility Directive” 2014/30/EU (formerly 2004/108/EC) is to ensure that electrical devices are designed and manufactured so that:
- Electromagnetic emissions are limited and low enough to permit other electrical devices to operate according to their intended purpose
- The level of built-in immunity to external disturbances enables them to operate according to their intended purpose.
This Directive applies to all electrical and electronic devices able to cause electromagnetic disturbances and whose operation can be affected by external factors.
The ATEX Directive 2014/34/EU applies to all equipment intended for use in potentially explosive. It is in force since 30 March 2014.
The ATEX Directive 2014/34/EU specifies minimum safety requirements for electrical devices used in environments classified as dangerous regarding the aspect of risk of explosion due to the presence of gas or dust.
The Directive divides equipment into groups and categories.
The manufacturer must decide, according to the use, the group and the category of belonging.
- Group 1: equipment intended for use in underground works, mines and their surface installations
- Group 2: equipment intended for use in environments where it is likely to occur explosive atmospheres
These product groups are than categorized according to the level of protection from the risk of ignition of potentially explosive atmospheres.
The products in the group 2 are divided into three categories:
- Category 1: equipment intended for high-risk areas where an explosive atmosphere is present long periods
- Category 2: equipment intended for medium-risk areas where an explosive atmosphere may occur under normal operating conditions
- Category 3: equipment intended for areas where an explosive atmosphere is only likely under abnormal
In each Member State, the role of the accredited Bodies is to assess and verify the compliance and the application of the European Directives.
Each State is responsible for the appointment and control of its own Bodies.
In Italy the authorized body to carry out accreditation activities is: Accredia. Accredia maintains a database with a list of all Italian organizations accredited for the various directives.
Notified Bodies are authorized to examine and certify machines and safety components in compliance with the applicable Directives.
Each Member State of the European Union is required to:
- Appoint the Notified Bodies by specifying their tasks
- Submit a list of the Notified Bodies to the European Commission and to the other Member States
The European Commission publishes a Directory of all the Notified Bodies on the Official Journal of the European Commission (GUCE), together with a list of the services, the machines and/or the safety components on which they are authorised to intervene.
The Member States of the European Union must make sure that these Bodies respect specified ethical and technical criteria.
- They are technical Standards conceived to meet the essential requirements of the Directives.
- They are written by the various technical committees on a mandate by the Commission of the European Union.
- They are approved and adopted:
- Then they are translated and published in the Official Journal of the European Committee (GUCE) and the Official Gazette of each Member State.
Status of the Standards
- prEN… a proposed standard (draft) which has not yet been definitely approved.
- EN…an approved standard already in force.
- TS…a technical specification.
The safety-related European standards are divided into 3 groups:
The European Standards concerning safety are subdivided into 3 groups:
TYPE A STANDARDS
They specify the general design principles applying to all types of machine e.g:
- EN ISO 12100 Safety of machines – basic concepts and general design principles – Risk assessment and risk reuction
TYPE B STANDARDS
They are divided into two classes:
- type B1 Standards: concerning a specific aspect of safety. e.g…
- EN ISO 13855 Positioning of safeguards with respect to approach speeds of parts of the human body
- EN ISO 13857-1 Safety distances for the protection of the upper limbs
- EN 60204 Safety of machinery. Electrical equipment of machine
- EN ISO 13849-1,2 Safety related parts of control systems
- type B2 Standards: concerning safety devices. e.g…
- EN 61496-1 Electro-sensitive protective equipment – general requirements and tests
- EN 61496-2 Electro-sensitive protective equipment-Particular requirements for equipment using active optoelectronics protective devices (i.e. light curtains)
- EN 61496-3 Electro-sensitive protective equipment-Particular requirements for Active optoelectronics devices responsive to diffuse reflection (i.e. laser scanner)
- EN ISO 13850 Emergency stop – Principles for design
TYPE C STANDARDS
They concern specific types of machine e.g:
- EN 692 Mechanical presses
- EN 693 Hydraulic presses
- EN 415 Packaging machines
- EN 415-4 Palletising and de-palletising systems
- EN ISO 10218 Industrial robots
A type C Standard takes priority over type A and B Standards.
If no C type Standards exist, compliance with the Directive can be attained on the basis of type A and type B Standards.