If you manufacture equipment and protective systems, find out how your products must comply with the ATEX Regulations
If you are a manufacturer of equipment and protective systems intended for use in potentially explosive atmospheres, you must comply with the requirements of the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 1996 - also known as ATEX Regulations.
These implement into UK law the European Directive 94/9/EC, and aim to ensure that these equipments and system satisfy wide-ranging health and safety requirements.
This guide outlines the main points of the Regulations, including definitions of equipment and protective systems, safety and marking requirements and will help you to ensure that your products comply.
Manufacturers of equipment and protective systems
The ATEX Regulations 1996 apply to both electrical and mechanical equipment, and protective systems for use on the surface, below ground and on fixed offshore installations.
Specifically, the Regulations relate to the following equipment and systems. If you manufacture any products matching the definitions, the Regulations apply to you.
All equipment intended for use in potentially explosive atmospheres. This is defined as machines, apparatus, fixed or mobile devices, control components and related instrumentation and detection or prevention systems which - individually or together - are:
- intended for the generation, transfer, storage, measurement, control and conversion of energy or the processing of material and which are
- capable of causing an explosion through their own potential sources of ignition
Protective systems intended for use in potentially explosive atmospheres. These are defined as design units which are intended to halt incipient explosions immediately and/or to limit the effective range of explosion flames and explosion pressures. Protective systems may be integrated into equipment or separately placed on the market for use as autonomous systems.
Safety devices, controlling devices and regulating devices intended for use outside potentially explosive atmospheres but which are required for or contribute to the safe functioning of equipment and protective systems, with respect to the risks of explosion.
Components defined as any item essential to the safe functioning of equipment and protective systems but with no autonomous function.
For the purposes of the Regulations equipment is divided into two groups:
- Group I - equipment intended for use in underground parts of mines, and to those parts of surface installations of such mines liable to be endangered by fire, damp and/or combustible dust
- Group II - equipment intended for use in other places liable to be endangered by explosive atmospheres
The groups are further subdivided as follows:
- Group I, Category M1 - equipment designed to be capable of remaining functional, even in the event of rare incidents relating to equipment, with an explosive atmosphere present
- Group I, Category M2 - equipment designed to be de-energised in the event of an explosive atmosphere
- Group II, Category 1 - equipment designed to be used in areas in which explosive atmospheres caused by mixtures of air and gases, vapours or mists or by air/dust mixtures are present continuously, for long periods or frequently
- Group II, Category 2 - equipment designed to be used in areas in which explosive atmospheres caused by gases, vapours, mists or air/dust mixtures are likely to occur
- Group II, Category 3 - equipment designed to be used in areas in which explosive atmospheres caused by gases, vapours, mists, or air/dust mixtures are unlikely to occur or, if they do occur, are likely to do so only infrequently and for a short period only
Explosive atmospheres and explosion safety
An explosive atmosphere is a mixture with air, under atmospheric conditions, of flammable gases, vapours, mists or dusts in which, after ignition has occurred, combustion spreads to the entire unburned mixture.
A potentially explosive atmosphere is an atmosphere that could become explosive due to local and operational conditions.
Equipment and protective systems intended for use in potentially explosive atmospheres must be designed from the point of view of integrated explosion safety.
To comply with the ATEX Regulations 1996, you must take measures that will:
- prevent the formation of explosive atmospheres that may be produced or released by equipment and by protective systems themselves
- prevent the ignition of explosive atmospheres, taking into account the nature of every electrical and non-electrical source of ignition
Should an explosion nevertheless occur which could directly or indirectly endanger persons, domestic animals or property, you must halt it immediately and/or limit the range of explosion flames and explosion pressures to a sufficient level of safety.
It is your responsibility to ensure equipment and protective systems are designed and manufactured after due analysis of possible operating faults to prevent dangerous situations. Any misuse which can reasonably be anticipated must be taken into account.
Selecting safe materials for use in potentially explosive atmospheres
Under the ATEX Regulations 1996, any materials used for the construction of equipment and protective systems must not trigger an explosion, taking into account foreseeable operational stresses.
Within the limits of the operating conditions laid down by you as the manufacturer, it must not be possible for a reaction to take place between the materials used and the constituents of the potentially explosive atmosphere that could impair explosion protection.
You must choose materials that will not become less safe over time, bearing in mind predictable changes in their characteristics and their compatibility in combination with other materials. In particular, you must take due account of the materials’:
- corrosion and wear resistance
- electrical conductivity
- impact strength
- ageing resistance and the effects of temperature variations
Equipment and protective systems must be designed and manufactured with due regard to technological knowledge of explosion protection, so they can be safely operated throughout their lifetime.
Components to be incorporated into or used as replacements in equipment and protective systems must be designed and constructed so that they function safely for their intended purpose of explosion protection when they are installed in accordance with your instructions as a manufacturer.
Potential hazards in potentially explosive atmospheres
As a manufacturer, under the ATEX Regulations 1996 you must take steps in the design and manufacturing process to ensure that your products are resistant to all types of hazard.
You must prevent hazards arising from:
- ignition sources - potential ignition sources such as sparks, flames, electric arcs, high surface temperatures, acoustic energy, optical radiation, electromagnetic waves and other ignition sources must not occur
- static electricity - electrostatic charges capable of resulting in dangerous discharges must be prevented by means of appropriate measures
- stray electric and leakage currents - in conductive equipment parts, which could result in, for example, the occurrence of dangerous corrosion, overheating of surfaces or sparks capable of provoking an ignition must be prevented
- overheating - caused by friction or impacts occurring, for example, between materials and parts in contact with each other while rotating or through the intrusion of foreign bodies must, as far as possible, be prevented at the design stage
- pressure compensation operations - equipment and protective systems must be so designed or fitted with integrated measuring, control and regulation devices that pressure compensations arising from them do not generate shock waves or compressions, which may cause ignition
- power failure - where equipment and protective systems can give rise to a spread of additional risks in the event of a power failure, it must be possible to maintain them in a safe state of operation independently of the rest of the installation
- connections - equipment and protective systems must be fitted with suitable cable and conduit entries. When equipment and protective systems are intended for use in combination with other equipment and protective systems, the interface must be safe
Equipment and protective systems must be so designed and constructed as to be capable of performing their intended function safely, even in changing environmental conditions and in the presence of extraneous voltages, humidity, vibrations, contamination and other external effects, taking into account the limits of the operating conditions established by you.
Equipment parts used must be appropriate to the intended mechanical and thermal stresses, and capable of withstanding attack by existing or foreseeable aggressive substances.
Placing of warning devices as parts of equipment
Where equipment or protective systems are fitted with detection or alarm devices for monitoring the occurrence of explosive atmospheres, the necessary instructions must be provided to enable them to be provided at the appropriate places.
Requirements for safety-related devices
As far as possible, under the ATEX Regulations 1996, failure of a safety device must be detected quickly to ensure that there is only minimal likelihood that dangerous situations will occur.
For electrical circuits, the fail-safe principle is to be applied in general. Safety-related switching must be able to activate the relevant control devices without being forced to use software.
In the event of a safety device failure, equipment and/or protective systems must, wherever possible, be secured. Emergency stop controls of safety devices must, as far as possible, be fitted with restart lockouts. A new start command may take effect on normal operation only after the restart lockouts have been intentionally reset.
Control and display units
Where control and display units are used, they must be designed to achieve the highest possible level of operating safety with regard to the risk of explosion.
Requirements for devices with a measuring function for explosion protection
Devices with a measuring function must be designed and constructed so that they can cope with foreseeable operating requirements and special conditions of use. Where necessary, it must be possible to check the reading accuracy and serviceability of devices with a measuring function.
They must also have a safety feature, which ensures that the alarm threshold lies far enough outside the explosion and/or ignition limits of the atmospheres to be registered.
Risks arising from software
In the design of software-controlled equipment, protective systems and safety devices, special account must be taken of the risks arising from faults in the programme.
Supplementary requirements for safety equipment
Under the ATEX Regulations 1996, equipment must have a means of protection such that:
- in the event of failure of one means of protection, at least an independent second means provides the requisite level of protection
- the requisite level of protection is ensured in the event of two faults occurring independently of each other
Where necessary, this equipment must be equipped with additional special means of protection. It must remain functional with an explosive atmosphere present.
Where necessary, equipment must be so constructed that no dust can penetrate it. The surface temperatures of equipment parts must be kept clearly below the ignition temperature of the foreseeable air/dust mixtures in order to prevent the ignition of suspended dust.
Equipment must be so designed that the opening of equipment parts that may be sources of ignition is possible only under non-active or intrinsically safe conditions. Where it is not possible to render equipment non-active, you must affix a warning label to the opening part of the equipment. If necessary, equipment must be fitted with appropriate additional interlocking systems.
How to show conformity with the Regulations
The ATEX Regulations 1996 define various procedures and specify the options available to manufacturers and to their authorised representatives established in the European Community (EC).
For equipment in Group I Category M1, equipment in Group II Category 1, autonomous protective systems, safety devices for such equipment or systems and for components for such equipment, systems or devices, the options are:
- EC type-examination, followed by either production quality assurance or product verification
- unit verification
For equipment in Group I Category M2, equipment in Group II Category 2, safety devices for such equipment or systems and for components of such equipment, systems or devices, the options are as follows.
For electrical equipment and internal combustion engines:
- EC type-examination, followed by either conformity to type or product quality assurance
- unit verification
For other equipment in these groups:
- internal control of production and depositing the technical documentation with a notified body
- unit verification
For equipment in Group II Category 3, safety devices for such equipment or systems and components for such equipment, systems and devices, the options are:
- internal control of production
- unit verification
If necessary, manufacturers should have an EC type-examination carried out by a Notified Body. Notified Bodies are appointed by member states to support the implementation of Directives, including Directive 94/9/EC.
An application for EC type-examination must be lodged by the manufacturer (or their authorised representative in the EU) with a Notified Body of their choice.
Production quality assurance
Under production quality assurance, the manufacturer should operate an approved quality system for production, final equipment inspection and testing, and apply to a Notified Body to have this assessed. The system will be subject to ongoing surveillance by the Notified Body.
Under product verification, the manufacturer should apply to a Notified Body to carry out the appropriate examinations and tests to check the conformity of equipment, protective system and devices with the EC type-examination certificate.
Conformity to type
Under conformity to type, the manufacturer should take all measures necessary to ensure that their manufacturing process assures compliance of the manufactured equipment or protective systems with the type as described in the EC type-examination certificate and with the relevant requirements of the Directive.
For each piece of equipment manufactured, the manufacturer should carry out tests relating to the anti-explosive protection aspects of the product, under the responsibility of a Notified Body.
Under unit verification, the manufacturer should apply to a Notified Body to carry out the appropriate examinations and tests to check the conformity of each individual piece of equipment, protective system or device.
For all of these procedures, you can download a list of UK Notified Bodies from the Department for Business, Innovation & Skills (BIS) website. (PDF, 117KB)
Technical documentation and quality marking
As the manufacturer, you are responsible for drawing up technical documentation for your equipment, protective systems and safety devices.
The technical documentation provides the enforcement authorities with the means of assessing the conformity of the safety equipment with the requirements of the ATEX Regulations 1996.
The documentation should include:
- a general description of the equipment
- conceptual design and manufacturing drawings and schemes of components, sub-assemblies, and circuits
- any descriptions and explanations that will aid understanding of the drawings and schemes and explain how the equipment operates
- a list of the standards applied in full or in part, and descriptions of the solutions adopted to meet the safety aspects of Directive 94/9/EC where the standards have not been applied
- results of design calculations made and examinations carried out
- test reports
As the manufacturer, it is your responsibility to compile the relevant documentation whether you are established in the European Economic Area (EEA) or not. However, the information must be kept within the EEA for inspection purposes.
You must also ensure that your manufacturing process is such that the production of the equipment conforms to that described in the documentation.
CE (European Conformity) marking is a visible declaration by you or your authorised representative that your equipment, protective systems and safety devices satisfy all the provisions of the Regulations.
Equipment bearing the CE mark will be taken as meeting the requirements and thereby entitled to free circulation throughout the EEA, provided that the equipment does in fact satisfy those requirements.
CE marking should be affixed to the equipment or, where not possible, to the packaging, the instruction sheet, or the guarantee certificate. The mark must be visible, easily legible and in an indelible form.
You should note that CE marking is not a European safety mark or quality symbol intended for consumers. Its purpose is to indicate to enforcement authorities that the equipment is intended for sale in the EEA.
Additional specific markings
Additional markings must enable full identification of equipment, protective systems and safety devices to be made. They must at least contain the following:
- the specific explosion protection mark, together with the mark indicating the equipment group and category; and, relating to equipment Group II, the letter ‘G’ (concerning explosive atmospheres caused by gases, vapours or mists) and/or ‘D’ (concerning explosive atmospheres caused by dust)
- the name and address of the manufacturer
- the designation of series or type and serial number
- the year of production
- restricted or other safety-related conditions of use
Failing to comply with the Regulations
The Health and Safety Executive (HSE) is responsible for the enforcement of the ATEX Regulations 1996 in Great Britain. You can read guidance on ATEX on the HSE website.
In Northern Ireland, enforcement is the responsibility of the HSE for Northern Ireland.
EU member states are required to take all appropriate measures to withdraw from the market any safety equipment bearing the CE marking and used in accordance with their intended purpose which are liable to endanger the safety of people and, where appropriate, of property. The member state must immediately inform the European Commission of such action and give reasons.
Where, after consultation with the parties concerned, the Commission finds that the measures are justified, it informs that member state and the other member states.
Member states are required to take action against anyone who affixes the CE marking to safety equipment which do not conform to Directive 94/9/EC and so inform the Commission and other member states.
It is an offence to supply safety equipment which does not comply with the requirements of the Regulations. Any person committing an offence is liable, under summary conviction, to imprisonment, a fine or both.