ATEX is the European guideline (2014/34/EU) for areas with a potential danger for explosions caused by the presence of an explosion dangerous atmosphere. Such area is called an ATEX (or EX) environment, ATEX (or EX) zone or ATEX (EX) area. The abbreviation ATEX is derived from the French ATmosphères EXplosibles. In Europe, explosion dangerous environments fall under the ATEX 153 guideline (formerly ATEX 137). This guideline aims to protect workers that are exposed to the danger of explosion from the explosion risks that are present. Machinery that operates in an Ex area with a present danger of explosion is subjected to the ATEX 114 guideline (formerly known as the ATEX 95 guideline).
The ATEX 114 guideline states the minimum and essential guidelines and safety demands to which machinery used in EX zones has to comply with. The purpose of the ATEX 114 guideline is to protect machinery by preventing that these form the source of ignition during normal use or in the case of occurring malfunctions. The goal of the ATEX legislation and guideline is preventing the explosion of an explosive atmosphere. There are three conditions to be met by an explosive atmosphere to be brought to explosion:
- Oxygen (air)
- Fuel (gas and/or dust mixture)
- Source of ignition (a sensor for example)
These three conditions are described as the so-called ATEX triangle, Explosion triangle or Hazard triangle. An explosion is preventable by securing one or more conditions of the ATEX triangle. The first step is usually the prevention or removal of the explosively hazardous dust and/or gas mixture or the oxygen (catalyst) in the air. Th second step is the prevention of ignition sources. Preventing the source of an ignition is possible by using spark-free tools for example. Or in the case of electrical machinery, such as sensors, it is made possible by equipping these with a suited protection method. For most of the Ex zones it is required to certify the final product by a Notified Body (NoBo).
In the explosion safety market the term IECEx is also used instead of ATEX. IECEx is the international organisation that operates under the supervision of the IEC (International Electrical Committee). The IECEx organization aims for the realization of an international standardization regarding explosion safety with the help of the harmonized norm IEC 60079. Up until now there only a few countries that have accepted the norm, such as Australia and New-Zealand. The probability of the IECEx norm to be accepted as the international standard is low. There are many countries that don’t allow EX products with just an IECEx certification (in compliance with the IECEx 02 certification table) into their markets. However, an IECEx certification often serves as a good basis for receiving a local certification. Examples of countries that use a local certification are the US and Canada (UL/CSA, NEC 500), Russia (CU TR 012), Brasil (INMETRO) and Japan (JPEx).
The big difference between an ATEX and IECEx certification is that in Europe an ATEX certification is mandatory and legally only valid in the EU. There is no country or continent in which the IECEx is mandatory, with the exception of Australia and New-Zealand. It is viewed as an international guideline upon which many local certifications are based, or at least show strong resemblance to. Many certifying organizations, also called Notified Bodies (NoBo), accept products that are IECEx 02 certified to realize the local certification. Despite the similarities between the guidelines there also differences. Thus, a product that complies with the IECEx 02 certification is almost always in compliance with the ATEX guideline while this is not the case the other way around. Another difference is that the ATEX 114 guideline is mandatory for an ATEX certification, while for an IECEx certificate it is mandatory to meet the norm IEC 60079. The ATEX 114 guideline is supported by the norm IEC 60079. In addition, it is allowed within ATEX to deviate from the IEC-EN 60079 norm while within the IECEx 02 certification system this is prohibited and thus not accepted.
Lastly, it is important to know that for an ATEX certified product it is mandatory to apply the Ex marking on it. There are strict demands tied to this marking to guarantee that the right information is shown correctly. The identification plate and Ex marking have to at least contain the following information:
- Equipment group
- Type of protection
- ATEX certification number + certification type
- Serial number
- Name, address and contact information of the manufacturer
- Essential instructions for safe use
- Ex and CE logos