A hazardous area is defined as any place in which an explosive atmosphere may occur. Hazardous areas may exist due to flammable gases or vapours or combustible dust. Explosions can cause loss of life and serious injuries as well as extensive damage. If there is enough quantity of flammable substance (the fuel) mixed with oxygen (the oxidizer), an ignition source (e.g. an electric spark) is sufficient to cause an explosion, in which combustion spreads to the entire mixture yet unburned, and can be caused by unadapted light fixtures.
Where can explosive atmospheres be found?
Many workplaces may develop or have activities that produce explosive or potentially explosive atmospheres. Examples include places where work activities create or release flammable gases or vapours, such as:
– Vehicle paint spraying,
– Metal processing facilities, where explosive metal dusts may form.
– Processing units of raw materials that generate fine organic dusts such as grain flour or wood manufacturing units.
The potential for explosive atmospheres can exist in a range of mainly industrial locations such as mines, factories, agricultural silos, and oil and gas platforms, water and other chemical processing environments. There is a wide range of products intended for use in such areas, including control equipment and sensors, transformers, fans, pumps, compressors, fork lift trucks, and lighting.
Why the ATEX Directive?
Preventing releases of hazardous substances, which can create explosive atmospheres, and preventing sources of ignition are two widely used ways of reducing the risk. Using the correct equipment in compliance with standards can also help greatly in preventing the risk. The ATEX Directive is a European Directive that applies to electrical and mechanical equipment and protective systems intended for use in potentially explosive atmospheres. The Directive replaces two previous Directives on electrical equipment for use in potentially explosive atmospheres (76/117/EC and 82/130/EC). It came into force on 1 March 1996.
The Directive applies to both electrical and mechanical equipment and protective systems 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,
-components relating to the above.
What is ATEX?
ATEX is the name commonly given to the two European Directives for controlling explosive atmospheres:
1) Directive 99/92/EC (also known as ‘ATEX 137’ or the ‘ATEX Workplace Directive’) on minimum requirements for improving the health and safety protection of workers potentially at risk from explosive atmospheres
2) Directive 94/9/EC (also known as ‘ATEX 95’ or ‘the ATEX Equipment Directive’) on the approximation of the laws of Members States concerning equipment and protective systems intended for use in potentially explosive atmospheres.
This Directive for manufacturers includes all requirements to be met by equipment especially the CE marking. It classifies ATEX zones according to their risk and flammable substances (gas or dust) and categories of equipment appropriate to each area depending on the activity (mining or surface industries).
This classification enables appropriate selection of the lighting equipment best suited to the ATEX zone. Legislation enables the free trading of ATEX products within the EEA by removing the need for separate documentation and testing for each individual European market. Manufacturers may use a single CE mark on their products to show compliance with this (and any other relevant) Directive. Manufacturers may use a single CE mark on their products to show compliance with this (and any other relevant) Directive.
For example, the lighting fixture Airfal Pyros is an Atex -approved fluorescent tube made of a polycarbonate with aluminum caps. Its ATEX 94/9 EC marking is II 2GD Ex d IIC T6 Ex tD A21 IP66 T85 ° C
II: equipment group (I = mining and II =all above ground or surface industries)
2 Equipment category (1 = permanent risk (Zones 0 and 20), 2 = frequent risk (Zones 1 and 21)
3 = occasional risk (Zones 2 and 22))
GD: Type of fuel source. G = gases and vapours, dust = D
Ex: Product meets Cenelec protection standards
d: specific protection type. In this case, there is an explosion proof enclosure. The number of letters depends on the type of protection and if the equipment is electrical or not.
IIC: Classes of gases or vapours covered by the product
T6: Temperature class corresponding to a surface temperature of 85º C.