People speak very often about ATEX Standards in general terms but we’ve realized that the topic is not always entirely clear. It’s worthwhile, therefore, to reflect a little on what they are and how they should be used.

What is Atex?

ATEX stands for "Explosive Atmosphere". Those who follow this newsletter know what an explosive atmosphere is. Therefore, here we will only give a hint. An explosive atmosphere is a mixture of flammable substances that may be in the form of gas, vapor, mists or dusts. In presence of oxygen and a source of ignition, it may cause an explosion.

The European Union, through the years, has defined and issued two standards on health and safety: the ATEX 94/9/EC (or ATEX 95, before ATEX 100a) and the ATEX 99/92/EC (or ATEX 137). They are not technical standards, as often interpreted, but EU laws which, once compulsorily acquired by EU Member States, have become laws in every states and basis for defining the legal aspects of the matter.

The two standards refer to technical regulations that are continually subject to change in order to be updated to technological developments. These technical regulations cannot be considered valid until they are referenced and accredited by the Standard. Every six months, the European Union issues in its gazette the revision of the Standards’ Annex in which are called all the valid standards.

The reason of two Standards

Too often we talk about the ATEX Standard instead of ATEX Standards. The ATEX 94/9/EC Standard establishes the essential safety requirements and protective systems for the use in areas with presence of an explosive atmosphere. The second Standard, the ATEX 99/92/EC, defines the minimum requirements in terms of health and safety in workplace where may be present an explosive atmosphere. In essence, the first directive is relevant to the construction and the use of equipment, while the second concerns mainly the hazard classification and the implementation of measures to prevent an explosion or to limit the damages. Let see below very briefly the characteristics of the two Standards that we will examine further in the future newsletters.

ATEX 94/9/EC

This Standard applies to all electrical and mechanical products, intended for use in areas at risk of explosion and defines the Essential Safety Requirements (ESR) that such products must meet to be used. In particular, the Standard defines the products categories, in order to identify immediately the areas where they can be installed, and the procedures to achieve in order to obtain the conformity. This Standard is also relevant to safety, regulation and control equipment which, although they’re not installed in hazardous locations, are involved in the overall system that ensures security. In the table below, you can find the products classification.

ATEX 99/92/EC

The ATEX Standard 99/92/EC defines the minimum requirements for improving the safety and health protection of workers exposed in explosive atmospheres. The risk assessment must be carried out by personnel with specific expertise in this matter. 

The Standard recalls in its Annexes the technical standards which define the classification of hazardous areas for the presence of gases, vapors, mists or dusts. It also refers to the relevant standards for the proper design of a system installed in locations with a potentially explosive atmosphere, the proper installation and the following verification and maintenance operations.

In the table below, you can find the main regulations mentioned in the Directive.