The ATEX Directive

By Stephen L D'Henin, Technical Director, Epsilon Technical Services Ltd

A good example of the potential impact of a new European Directive is the ATEX Directive, 94/9/EC. This Directive replaces the old 'Explosive Atmospheres and Gassy Mines Directive', 7611171EEC and is intended to bring products covered by the old directive into line with the other, so called, 'New Approach' CE marking Directives. The Directive covers equipment and protective systems, which may be used in areas endangered by potentially explosive atmospheres created by the presence of flammable gases, vapours, mists or dusts. The Directive covers both electrical and mechanical equipment.

Differences Between the Old and New Directives

The main differences are:

The inclusion of non-electrical equipment
The inclusion of dust atmospheres
Requirements for safety related devices (flame arrestors, suppression systems etc.) and safe area equipment
Additional quality system requirements
The need to produce a 'Technical File'

Products Covered

The Directive includes equipment and safety or control devices installed outside the potentially explosive area but having an explosion protection function. A wide range of products comes within the definition of equipment, including electric motors, compressors, diesel engines, lighting fittings, control and communication devices and monitoring and detection equipment, to name but a few. "Protective Systems" are also included, and include items that prevent an explosion that has been initiated from spreading or causing damage. They include flame arrestors, quenching systems, pressure relief panels and fast acting shut-off valves to name but a few.

Product Exclusions

The Directive, however, does exclude the following product types:

Medical devices
Products for use in the presence of explosives
Products for domestic use
Sea-going vessels and mobile offshore units
Military equipment
Personal protective equipment covered by directive 89/686/EEC
Means of transport by air or on road or rail or water networks. Vehicles intended for use in an explosive atmospheres are not excluded

Directive Implementation

The Directive came into effect on a voluntary basis on 1 March 1996, however, from 1 July 2003, it will be necessary for all products intended for use in potentially explosive atmospheres, placed on the market or put into use, to comply with the ATEX Directive.

Approval Lead Times

As the Directive will require the use of a Notified Body for equipment intended for use in Zone 0 (an area where an explosive atmosphere is continually present - for example inside liquid fuel storage tanks) and Zone 1 (an area where an explosive atmosphere will be present in normal operation but not continually -for example re-fuelling areas) classified areas. There will probably be a very long lead time for certification, as all existing certified equipment will have to be recertified to the ATEX Directive if the manufacturer wishes to continue selling it in to Europe.

Self-Certification

Products which are intended for use in Zone 2 (an area where an explosive atmosphere will be present only under abnormal conditions for short periods -for example solvent storage areas. The solvent is normal contained in sealed drums however, if a drum is damaged during the process of moving it then a potentially explosive atmosphere could exist for a short period) will not require the involvement of a Notified Body for approval. These products can be selfcertified or if the in-house resources are not available, then third party approvals from a suitable test house can be used. (Epsilon can advise on the best route for Zone 2 approvals).

Stephen D'Henin and Sean Clarke of Epsilon


Stephen D'Henin and Sean Clarke of Epsilon

Conversions of Existing Certification

The vast majority of equipment certified before 1994 will not comply with the latest Harmonised Standards for the ATEX Directive and, manufacturers who do not consider the design implications now are liable to be caught out in the very near future. It is imperative that before putting your equipment up for certification you ensure that you are now compliant with all of the 'latest' relevant Harmonised European Standards and the Essential Health and Safety Requirements (EHSR) of the Directive.

The ATEX Directive now means that far more equipment will require certification. This relates mainly to the need for mechanical equipment and protective system to comply with the Directive. Presently there are over 70 new standards being prepared by CEN committees specifically for these types of equipment.

Harmonised Standards

The preparations of the harmonised standards are the responsibility of CENELEC and CEN technical committees.

What are CEN and CENELEC?

CENELEC is the European Committee for Electrotechnical Standardization.
CEN is the European Committee for Standardization.

CENELEC and CEN are European standardization bodies recognized as competent in the area of voluntary technical standardization and listed in Annex 1 of the Union Directive 98/34/EC (replacing 83/189/EEC) concerning 'the information procedure' for standards and technical regulations. Together they prepare European Standards in specific sectors of activity. When these standards are prepared in the framework of the 'new approach' directives, they are known as 'harmonized standards' and will be cited in the Official Journal. Products manufactured in accordance with these standards benefit from a 'presumption of conformity' to the essential requirements of a given directive.

The preparations of the standards (EN50 series) covering electrical products have been completed by CENELEC and are now included in the Official Journal. The standards for mechanical products and protective systems are still either under development or under approval, none have, at the time of writing, yet been adopted.

Product Categories

Products are required to be categorised by the level of protection that they offer against the risk of them becoming a potential source of ignition of an explosive atmosphere.

The equipment conformity categories are: Equipment Group I (mining):

M1 - High integrity of protection for mining equipment. Two fault conditions
M2 - Reliability concept of protection for mining equipment

Equipment Group II (non-mining):

CAT 1 (Zone 0) - Still safe with two faults
CAT 2 (Zone 1) - Increased safety under abnormal operating conditions
CAT 3 (Zone 2) - Equipment which is appropriate in normal operating conditions

The marking of the equipment with the category will help the end-user with their selection of the equipment in that it identifies which Zone it can safely be installed in. This is a major improvement over the old cryptic marking system that only listed the protection concepts used in the design of the equipment. This meant that the user of the equipment had to be familiar with all eight recognised protection concepts and furthermore had to know which of them was suitable for a particular type of Zone.

Quality Requirements

The Directive specifies quality assurance requirements - ATEX Quality Modules. These modules are issued to the product manufacturer by the Notified Bodies. The issuing of the modules is dependant upon the manufacturer achieving a satisfactory level of quality control which is determined by an external audit performed by the Notified Body. Maintaining the quality module will be dependant upon a periodic audit program which again is carried out by the Notified Body. There are two quality modules specified in the directive.

These are:

Production Quality Assurance: which applies to equipment in categories 1 and M1 and to protective systems
Product Quality Assurance: which applies to electrical equipment and internal combustion engines only, in categories 2 and M2

For equipment in category 2 and M2 which is neither electrical or internal combustion engines, and to category 3. The manufacturer is responsible for ensuring that the equipment is in compliance with the Directive by the means of internal control of production.

The Directive requires the quality assurance system to address the following points:

Quality objectives, organisational structure, responsibilities and powers of management with regard to equipment quality
Manufacturing, quality control and quality assurance techniques, processes and systematic actions which will be used
Examinations and tests which will be carried out before, during and after manufacture and frequency with which they will be carried out
Quality records (inspection reports, test data, calibration data, qualifications of personnel, etc)

These points will be covered by a quality system complying with ISO 9002:1994.

The 'USE' Directive

Coupled with the ATEX Directive is a new Directive for 'The Protection of Workers at Risk from Potentially Explosive Atmospheres' (1999/92/EC) commonly known as the 'Use' directive. This Directive will also be mandatory under EU law in 2003. It requires that Site's documented evidence of risk analysis; area classification and site inspections to be carried out where potentially explosive atmospheres (gas or dust) may develop. This 'use' Directive ensures that only ATEX certified electrical, mechanical and safety related systems are installed in potentially explosive atmospheres.

The full text of the ATEX Directive was published in the Official Journal of the European Communities No L 100, dated 19 April 1994. Details of this Directive along with the 'Use' Directive can be found at www.epsilon-ltd.com

Summary

If you are a manufacturer of products intended for use in potentially explosive atmospheres or operate, a plant that produces such areas then now is the time to start working towards satisfying the requirements of the ATEX and 'Use' Directives. If manufacturers and users think that July 2003 is still along way off and that, they will deal with the associated issues near to the time. Then they are potentially putting themselves into the position of not being able to sell their products or operate their plants from the cut-off date. The Notified Bodies already have relatively long lead times for product approval, which will only increase as the implementation date of the Directive approaches. Additionally, a significant number of products that are covered by approvals issued prior to 1994 will require some redesign work in order to satisfy the latest approvals standards. Therefore, now is the time to start the process of gaining compliance with the Directive if you are not to be left behind in 2003.

Epsilon offer Design Consultancy, Testing (they have full in-house facilities for EMC, LVD and ATEX testing) and Product Certification. They can also offer to completely manage your compliance issues (for example, CE marking) taking full responsibility for documentation, testing, updates, continued compliance (new directives and product modifications) and declarations. Tel: 01244 541551

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