Overview of Potentially Explosive Atmospheres (ATEX) Directive

In Europe, equipment that is for use in, or intended to be connected to equipment used in, a potentially explosive atmosphere is required to be of a specific design such as flameproof, increased safety, intrinsic safety, etc.

The Potentially Explosive Atmosphere (94/9/EC) Directive applicable to these products is commonly referred to as the "New Approach" or ATEX Directive. Depending on the equipment, other European Directives may also apply, such as Electromagnetic Compatibility (2004/108/EC) or Machinery (2006/42/EC) Directives. The decision as to the Directive applicability should be made only after a thorough review and understanding of each Directive.

"New Approach" or ATEX Directive

Note: The "Old Approach" Directive for Potentially Explosive Atmospheres (76/117/EEC, along with 79/196/EEC and all of its amendments) is no longer available for certification as of June 30, 2003.

On March 1, 1996, a transitional period began for the implementation of the ATEX Directive (94/9/EC). This Directive applies to electrical and non-electrical equipment/components and protective systems intended for use in potentially explosive atmospheres. The ATEX Directive became mandatory on July 1, 2003.

Equipment located outside potentially explosive atmospheres are also covered by the ATEX Directive under the following conditions:

• The equipment is a safety device, controller or regulatory device
• The equipment is required for the safe function of equipment or protective systems with respect to the risk of explosion

Products covered by the ATEX Directive are excluded from the Low Voltage Directive.

In addition to the "Epsilon X" mark, all equipment under its scope will be required to bear the European CE Marking as verification of compliance with the Directive (the CE Marking will not appear on components defined by this Directive). The ATEX Directive specifically defines procedures for the evaluation of a product's design and manufacture (production) based on Equipment Groups and Categories. This is briefly outlined below.

Equipment Group I Overview

Equipment intended for use in underground parts of mines, and to those parts of surface installations of such mines, liable to be endangered by firedamp and/or combustible dust.

Equipment Group II Overview

Equipment intended for use in other than Equipment Group I places that are liable to be endangered by explosive atmospheres.

Additional Equipment Group/Category Details

The Annexes of the ATEX Directive detail the specifics pertaining to the required conformity assessment procedures based on the Equipment Groups/Categories noted above.

The following provides a more detailed summary of the conformity assessment options available to manufacturers (with references to the applicable ATEX Directive Annex):

1. For all Equipment Group/Category combinations: Unit Verification (Annex IV) is available. Under this option, the manufacturer declares compliance with the directive and the NB verifies compliance, conducting tests as necessary. This Annex is primarily intended for one-time evaluations or unique products.

2. For Equipment Group I, Category M1 and Equipment Group II, Category 1 (electrical and non-electrical equipment):

• Essential Safety Requirements (Annex II): It is the responsibility of the Notified Body (NB) to verify compliance to the ESRs as part of an EC-Type examination (see below).
• EC-Type Examination (Annex III): The manufacturer is required to submit documentation and samples to the Notified Body, or test lab. The Notified Body (NB) is required to verify compliance with the directive. This includes verifying that the manufacturer meets the ESRs of the directive, evaluation to the EN 60079 series of standards, and the continuing verification such as quality assurance, product verification, or conformity to type (see below).
• Production Quality Assurance (Annex IV): The NB verifies compliance with a design and manufacturing quality assurance program, i.e., EN 13980:2002 (and ISO 9001:2008).
• Product Verification (Annex V): The NB evaluates each sample of a product as it is produced by the manufacturer. The NB is involved from start to finish in the manufacturing process.

3. For Equipment Group I, Category M2 and Equipment Group II, Category 2 (electrical equipment only):

• Essential Safety Requirements (Annex II): It is the responsibility of the Notified Body (NB) to verify compliance to the ESRs as part of an EC-Type examination (see below).
• EC-Type Examination (Annex III): The manufacturer is required to submit documentation and samples to the Notified Body (NB), or test lab. The NB is required to verify compliance with the directive. This includes verifying that the manufacturer meets the ESRs of the directive, evaluation to the EN 60079 series of standards, and the continuing verification such as quality assurance, product verification, or conformity to type (see below).
• Conformity to Type (Annex VI): Routine tests are conducted by the manufacturer or by the NB on the manufacturer's behalf on each piece of equipment manufactured. The manufacturer has the responsibility to ensure that samples are constructed identically to those originally investigated by the NB.
• Product Quality Assurance (Annex VII): The NB verifies compliance with a manufacturing quality assurance program, i.e., EN 13980:2002 (and ISO 9001:2008).

4. For Equipment Group II, Category 3 (electrical and non-electrical equipment), and For Equipment Group I, Category M2 and Equipment Group II, Category 2 (non-electrical equipment only):

• Essential Safety Requirements (Annex II): It is the responsibility of the manufacturer to verify compliance to the ESRs.

Internal Control of Production (Annex VIII): The manufacturer self-declares compliance with all provisions of the directive.