What is ATEX?

What is ATEX

In this article, we will consider what ATEX entails, which guidelines and standards are involved and what information must be shown on an nameplate of an ATEX sensor.

The European directive for areas with explosive atmospheres

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. One example is an oil platform. 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 directive describes the minimum and essential guidelines and safety requirements that equipment used in Ex zones must meet. The ATEX 114 directive aims to protect equipment so that it cannot be a potential source of ignition under normal use or under occurring fault conditions. The basic premise of the ATEX laws and regulations is to prevent an explosive atmosphere from turning into an explosion.

The ATEX triangle

To detonate an explosive atmosphere, such as an oil platform, three preconditions are required:

• Oxygen (air);
• Fuel (gas or dust mixture), in this case the oil being extracted;
• An ignition source (for example, a sensor overheating)

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).

ATEX versus IECEx and other (local) certifications

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 harmonised standard IEC 60079. Up until now there only a few countries that have accepted the standard, such as Australia and New-Zealand. The probability of the IECEx standard 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).

Differences with IECEx

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 IEC 60079 standard. The ATEX 114 guideline is supported by the IEC 60079 standard. In addition, it is allowed within ATEX to deviate from the IEC-EN 60079 guidelines while within the IECEx 02 certification system this is prohibited and thus not accepted.

ATEX marking and nameplate

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 and Zone classification
• Type of protection
• ATEX certification number + certification type
• Serial number
• Name, address and contact details of the manufacturer
• Essential instructions for safe use
• Ex and CE logo on nameplates

Products with ATEX certification

An example of an ATEX certified product is the LAM 300 Ex d distance laser which is equipped with an ATEX housing. Each ATEX product specifies the compatible zone certifications that indicate in which zones the product may be used. In addition, it also has EN standards that provide information about, for example, the requirements that the product used complies with.

The LAM 300 Ex d laser has the following Zone certifications and conforms to the following EN standards:

• IECEx certification gas: Gas II 2 G Ex d IIC T5/6
• IECEx certification dust: Dust II 2 D Ex tb IIIC T85°C. Db IP 66
• EN-IEC 60.079-0
• EN-IEC 60.079-1
• EN-IEC 60.079-28
• EN-IEC 60.0790-31