HELP LINE +44 (0)1298 873800

Purpose

The ATEX Directive (94/9/EC) is one of a series of measures introduced under article 100a of the Treaty of Rome. Article 100a directives all have the primary objective of creating a single European market in goods and services with the objective of providing producers and consumers with the benefits of economies of scale that this offers.The effect of the directive has been to introduce identical requirements for the safety of equipment for use in explosive atmospheres in every country within the European Economic Area (EEA).The name of the Directive comes from the French ATmospheres EXplosibles.

Prior to the introduction of the Directive, most countries within the EU had schemes for the certification of electrical equipment and required the use of such equipment in certain locations such as gassy mines. However, there were many anomalies in the legislation.

Directive 94/9/EC covers equipment. A complimentary Directive, 1999/92/EC, is specifically concerned with worker safety and places requirements on employers whose staff may work in an explosive atmosphere.

In many respects the directive simply regularises the existing regime for electrical equipment for use in explosive atmospheres. However, there are some important changes - for the first time, non-electrical equipment will be subject to assessment and (in some cases) certification requirements, and locations affected by combustible dusts are also included.

Implementation dates

The Directive came fully into force on 1 March 1996. During a transitional period which ended on 30 June 2003, manufacturers could continue to sell equipment which meets the pre-existing national rules, but from 1 July 2003, all equipment within the scope of the Directive must carry the CE and Ex marks and comply with the directive's requirements.

Scope

The Directive applies to all equipment to be used in a hazardous area (where an explosive atmosphere might occur). Both electrical and mechanical equipment is included. It also applies to protective systems intended to prevent propagation of an explosion.

An explosive atmosphere is defined as a "mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts in which, after ignition has occurred, combustion spreads to the entire unburned mixture".

The directive specifically does not define atmospheric conditions. However, guidance from the Commission indicates that "a surrounding temperature range of -20°C to 60°C and a range of pressure between 0.8 bar and 1.1 bar may be appropriate as a basis for design and intended use of products". Hence the interiors of most chemical reactors and pressure vessels and environments with unstable or explosive substances are excluded.

The Directive only applies where there is equipment which introduces energy into the hazardous area such as electrical equipment which introduces electrical energy or mechanisms introducing mechanical energy. It is not intended to apply to locations where there is no equipment. Therefore, the interior of storage tanks or vessels would not be covered unless there was equipment present.

Equipment and protective systems used outside the hazardous area but which contributes to safety in the hazardous area (sometimes known as associated equipment) is also covered. This includes barriers for intrinsically safe circuits, control systems of explosion suppression, inerting and decoupling systems.

There are some exclusions which are common with other directives. These are mostly carefully chosen items of equipment where application of the ATEX requirements would lead to anomalies in the application of other directives or difficulties in application due to other treaties which cover areas greater than just the EEA. Examples of excluded equipment include medical devices, personal protective equipment and domestic gas appliances, as well as equipment used for transport by sea, air, rail and road.

Equipment which was first used within the EEA prior to the end of the transitional period (i.e. before 1 July 2003) does not have to comply with the directive, it can comply with national regulations instead. However, if that equipment is refurbished or upgraded so that its original specification is changed, it will have to be made to comply with the full requirements of the Directive. Any equipment to which the Directive applies and which was manufactured before 1 July 2003 must be made to comply with the directive if it subsequently brought into Europe from outside just as would any newer equipment manufactured outside the EU.

Equipment manufactured for the manufacturer's own use is not excluded from the requirements and will have to be made to comply as if it were made for sale to a third party.

Enforcement

The Equipment Directive 94/9/EC has been implemented into United Kingdom law by Statutory Instrument (S.I.) 1996:192: The Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations, 1996. The worker safety directive 1999/92/EChas been enacted as Statutory Instrument (S.I.) 2002:2776: The Dangerous Substances and Explosive Atmospheres Regulations 2002. Further details can be found on the HSE web site and the text of the Regulations can be obtained from the OPSI web site.

The Regulations are enforced in the United Kingdom by the Health and Safety Executive.

Penalties

In the UK the maximum penalty for the supply of non-compliant machinery is three months imprisonment and/or a £5000 fine. More importantly, the regulations also give the authorities the power to force manufacturers to recall or replace faulty product - potentially a far more onerous penalty.

It should also be remembered that any incident which involves injury or damage will fall within the scope of other legislation, for example the The Health and Safety at Work Act 1974 and The Consumer Protection Act 1987. These laws provide for greatly increased penalties than those available under the 1996 Regulations.

Equipment Classification

The directive does not use Zone numbers in the classification of hazardous areas, preferring to refer to their definitions (e.g. 'An area where an explosive atmosphere occurs frequently or continuously' for Zone 0) but it is useful to understand the classification system commonly used to describe areas where explosive atmospheres may occur. Usually, a series of zones based on the likelihood of presence of an explosive atmosphere are defined (the following are based on BS EN 60079-10: 2003):

Equipment is selected on the basis of its suitability for use in these conditions. There is a sub-division which separates equipment for use in mines from all other equipment. The full list of categories are as follows:

Requirements

Annex II of the Directive gives a set of essential safety requirements for equipment covered by the directive. These include requirements for the selection of materials, marking, user instructions and design and construction to ensure that the probability of ignition sources becoming active when an explosive atmosphere is present is negligible. Detailed requirements are laid out in a series of safety standards, many of which are still in the process of development (particularly those relating to non-electrical equipment and to dusts).

The standards offer a number of ways of providing safe equipment, including flameproofing of enclosures, pressurisation, powder filling and intrinsic safety. Not every method can be used in every case - for example, intrinsic safety cannot be applied to high power circuits - and the standards which provide guidance on the classification of hazardous zones and on the selection of equipment (see various parts of IEC 60079 and the EN equivalents) do not permit all protection methods to be used in all locations.

Equipment intended for use in the higher risk categories will be required to undergo independent certification by a Notified Body. The actual relationship between the location and the certification requirements is as follows:

Where certification of the product by a Notified Body is required, the manufacturer's quality control system will also need to be independently reviewed and audited.

The Directive requires the machines manufacturer to produce a Technical File containing documentary evidence that the machinery complies with the directive. The form and content of the Technical File is only loosely dictated in the Directive but typically it will contain the following items:

• Drawing(s) of the equipment with information related to explosion protection.
• Copy of installation/user/maintenance manuals
• Wiring and circuit diagrams
• Copies of reports and certification from Notified Body
• Assessment of the electrical system to the appropriate standards
• Assessment of the mechanical equipment to the appropriate standards
• Assessment of the equipment as a whole to the EHSR's of the Directive
• Zoning assessment, calculations and zone diagrams where applicable.
• Ignition hazard assessment report.
• Drawings of markings and labels related to explosion protection and where they are located on the product
• Design calculations
• Copy of the Declaration of Conformity
• Manufacturer's data sheets for safety critical components and sub assemblies.
  

Equipment meeting the requirements of the Directive is required to have the CE logo clearly affixed to indicate compliance and also the ATEX symbol alongside the relevant hazardous atmosphere specification markings.

Useful links

The European Commission have a special section on ATEX with a great deal of useful information on their EUROPA server. This includes the full text of the directive, lists of the current harmonised standards as well as guidance and interpretative documents and a list of the national implementing measures in each of the member states of the EU.

For details of draft standards, the New Approach web site is a good EU-funded resource.

The UK government's Department for Business Enterprise and Regulatory Reform (BERR; formerly the DTI) publish a number of useful guides on the Directive and these are available for download.

Useful information may also be found on the Health and Safety Executive web site.

Links to some bodies notified under the directive can be found on our Notified Bodies page.

Further advice

As with all CE marking directives, the actual requirements for any piece of equipment under the directive are complex and dependent on not only the design but also the type of user, the intended use and sometimes even what is claimed in the instructions or sales literature.

For further advice specific to your products, please contact us at Conformance and we will be pleased to discuss your needs. If you'd like us to prepare a no-obligation quote for assisting you with CE marking your products, please take a look at our page which gives details of the information required in order to be able to give you an accurate idea of the costs and procedures involved.

© Conformance Ltd. | Registered in England, Company No. 3478646 | VAT No. GB 741 1166 65