European ATEX legalisation therefore has two different ATEX directives. ATEX Directive 2014/34/EU (also known as ATEX 114/product directive) falls within the scope of CE Marking and applies to the manufacturer/supplier of ATEX equipment. ATEX equipment is built to a level of protection corresponding to the risk.

Directive 1999/92/EC (also known as ATEX 153/Social Directive) applies to sites with hazardous areas. Sites such as chemical plants, oil and gas installations must classify the workplace into hazardous areas depending on the frequency and duration that an explosive atmosphere is present in the form of gas, vapour, mist or dust. Employers must prepare and maintain an Explosion Protection Document (EPD).

In order to comply with ATEX directives, it is a legal requirement to engage a third party body. This body is notified by a national government to the European Commission to carry out acts related to a directive known as the ATEX Notified Bodies Group (ExNBG). Also known as an ATEX Notified Body (NB).

The European Commission authorises suppliers to sell Ex products in the EU. This is based on the seller’s declaration that the product meets the essential health and safety requirements of the ATEX directive. This declaration is called the EU Declaration of Conformity (DoC). It is a declaration made by the manufacturer of the equipment and delcares, on the manufacturer’s sole responsibility, that they have all the necessary documentation and evidence to comply with the ATEX Directive.

The ATEX directives are required by law for both electrical and non-electrical equipment marketed or sold in the EU that can be used in potentially hazardous environments.

Which ATEX zones apply? Why do ATEX zones exist and what are the definitions? The first European directive is ATEX 153 (Directive 1999/92/EC), which requires owners to identify ATEX zones in areas with explosive sources. This zone classification must be included in the Explosion Protection Document (EPD).

The explosion risk is determined on the basis of a risk inventory and evaluation. Seamlessly, we move to the ATEX 114 directive (Directive 2014/34/EU). This directive specifies approved equipment by category, indicates in which zones they can be used, to prevent the equipment from causing ignitions.

An ATEX area is defined by the probability that an explosion may occur. Explosive atmospheres can be created by flammable gases, vapour, mist or dust. When enough of this is present, mixed with atmosphere (oxygen) and an ignition source, it can cause an explosion. The explosion hazard can take the following forms:

• Gas explosion
• Mist explosion
• Dust explosion

ATEX zones for gas or mist explosion hazards are designated ATEX Zone 0, 1 or 2. The ATEX zones for dust explosion hazard are designated ATEX Zone 20, 21 or 22.

The following aspects must be considered when defining ATEX zones:

• Hazardous sources, all points where gas, vapour or dust can potentially break out should be documented.
• The quantities of gas, vapour and dust that can be released should be calculated.
• The probability of a hazardous explosive mixture being present is calculated.

The ATEX directives play a crucial role in ensuring safety of eletrical and non-eletrical equipment used in potentially explosive environments within the European Union. The ATEX zones determine the level of risk associated with explosive atmospheres. Understanding and adhering to these directives and zone classifications are vital for maintaining workplace safety and preventing potential ignition sources.