Atex Directive and Explosion Prevention
The EU Product Directive (2014/34/EU) specifies requirements for equipment that is used in potentially explosive atmospheres. It also specifies the requirements for protective systems that are needed for equipment protection.
What is Atex?
ATEX is the common name given to the EU Product Directive 2014/34/EU, Equipment and Protective Systems intended for use in Potentially Explosive Atmospheres.
The word ATEX is derived from the French "ATmospheres EXplosibles".
What is the Intent of the ATEX Directive?
The aim of Directive is to enable the free trading of ATEX products within the European Economic Area by removing the need for separate documentation and testing for each individual European market. Manufacturers may use a single CE conformity mark on their products to show compliance with this (and any other relevant) Directive. Certification ensures that the equipment or protective system is fit for its intended purpose and that adequate information is supplied with it to ensure that it can be used safely. See our page on CE marking for further discussion on the use of CE marks.
What Does ATEX Apply To?
The ATEX directive applies to both electrical and mechanical equipment intended for use in potentially explosive atmospheres.
These include:
- equipment and protective systems for use within potentially explosive atmospheres;
- devices for use outside potentially explosive atmospheres, but which are required for, or contribute to the safe functioning of equipment and protective systems located inside such atmospheres; and
- components relating to the above.
To What Industries Does ATEX Apply?
ATEX applies to any industrial location where there is a potential for an explosive atmosphere to exist, e.g. mines, factories, agricultural silos, oil and gas platforms, sewage plants and other chemical processing environments.
To whom does ATEX apply?
If you design, manufacture or sell any equipment or protective system intended for use in potentially explosive atmospheres within the EU, then you will need to comply with the ATEX Directive.
How do I Know if a Product Complies with ATEX?
The ATEX Directive sets a number of technical and quality objectives that must be complied with to the satisfaction of a notified body, but once these have been met, a manufacturer can mark his product with a CE Mark and is entitled to display the distinctive Ex mark.
The use of these marks shows that a piece of equipment complies with ATEX.
What Other Equipment Marking is Required?
The following marking should also be shown on all ATEX compliant equipment.
- CE Mark
- Ex-marking symbol followed by ATEX data
- Name and address of manufacturer
- Series or type, serial number
- Year of construction
- All further information essential to the safe use.
Marking, especially on small components can be an issue.
How to Read the ATEX label
Equipment Grouping
The ATEX Directive identifies two groups of equipment.
- Group 1 equipment is intended for use in mining applications. Divided into categories M1 and M2. M1 identifies equipment that must continue to operate when a potentially explosive atmosphere is present. M2 identifies equipment that does not operate when a potentially explosive atmosphere is present.
- Group 2 is intended for all other situations. Divided into categories 1,2 and 3. Category 1 equipment is intended for use in Zone O situations. Category 2 equipment is intended for use in Zone 1 situations. Category 3 equipment is intended for use in Zone 2 situations.
What are Zones?
Zoned areas are areas where there is a risk of flammable material being released to atmosphere, i.e. potentially hazardous areas. The subscripts 0, 1 and 2 describe the probability of a flammable material being released to atmosphere in explosive concentrations.
Equipment Protection Level
G means the item has been tested for potentially explosive atmospheres due to the presence of gas
D means the item has been tested for potentially explosive atmospheres due to the presence of dust.
Technical Library
The following pages on Control and Instrumentation.com give more detail on explosion protection and other topics associated with process plant safety:
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Technical Bookshop
For those who want to delve further into ATEX or just want to broaden their knowledge of functional safety, then the following books from Amazon will be of interest
