ATEX Directive and Regulations
ATEX is based on the requirements of two European Directives; one that applies to equipment manufacturers, and another for its end users.
Both Directives came into effect on 1st July, 2003:
- ATEX 95 (for equipment and protective systems, equipment directive 94/9/EC) was introduced back in 1995 when an 8 year transition period was given for manufacturers to comply.
- ATEX 137 (for the protection of workers, workplace directive 99/92/EC) was introduced in 1999 with a 4 year transition period granted for employers to comply.
The ATEX 95 (equipment 94/9/EC) directive is only applicable until 19th April 2016, when it will be replaced by a new directive: Directive 2014/34/EU harmonises the laws of the EU Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres.
Why do we need ATEX?
An explosion or fire naturally occurs when the right elements are present and combined in the right mixture, meaning that a fire is actually an event rather than a “thing”. Known collectively as the fire or combustion triangle, the three main elements that react together to create a fire or explosion are:
- Flammable material, the fuel;
- Heat or an ignition source;
- Oxygen or another oxidising agent.
Explosive atmospheres can be caused by: flammable solids (or fibres), liquids, gases, mists vapours or by combustible dusts. Many substances need very little energy to react; the most flammable substances are gases and vapours.
Examples of potentially explosive atmospheres in the workplace could include vehicle paint spraying and workplaces handling fine organic dusts such as grain flour or wood. If there is enough of such substances, mixed with air, then a source of ignition is all that is needed to cause an explosion.
Sparks, flames, electric arcs and hot surfaces are all examples of ignition sources, other potential hazards are:
- Static electricity: these charges can end up resulting in a dangerous discharge and must be prevented;
- Leakage currents: the overheating of surfaces in conductive equipment parts are capable of provoking an ignition and dangerous corrosion;
- Overheating: if two parts of a rotating system were to contact each other, overheating may occur. This risk should always be prevented at the design stage;
- Pressure compensation operators: equipment and protective systems must be fitted with integrated measuring, control and regulation devices that pressure compensations arising from them don’t generate shock waves or compressions;
- Power failure: in the event of a power failure, some equipment and protective systems can experience additional risks;
- Connections: equipment and protective systems must be fitted with suitable cable and conduit entries. When equipment and protective systems are intended for use in combination with other equipment and protective systems, the interface must be safe;
- Radiation: electro magnetic waves, optical radiation, ionising radiation and ultrasound.
Hazardous areas or locations are classified within the ATEX directive in terms of zones, on the basis of the frequency and duration of the occurrences of an explosive atmosphere. You can find out more about ATEX Area Classifications and ATEX Zones here.