ATEX lighting refers to specially designed lighting equipment that is certified for use in hazardous environments where there is a risk of explosion due to the presence of flammable gases, vapors, dust, or fibers. The term “ATEX” comes from the European Union directives that regulate equipment used in explosive atmospheres (Directive 2014/34/EU). These light fixtures are engineered to prevent any ignition sources, such as sparks or high surface temperatures, from interacting with the surrounding explosive atmosphere. ATEX lighting is commonly used in industries like oil and gas, chemical processing, pharmaceuticals, and grain storage, where safety and compliance with ATEX standards are critical.

ATEX zones are divided into two categories—one for gases, vapours or mists, and another for combustible dusts. Each zone indicates the likelihood and duration of an explosive atmosphere being present, helping determine the appropriate safety measures and equipment. The higher the risk, the stricter the requirements for ATEX-certified lighting and devices. See more detail surrounding each zone below:

Zone 0

Gas, vapour or mist

– Explosive atmosphere is present continuously or for long periods.

Zone 1

Gas, vapour or mist

– Explosive atmosphere is likely to occur during normal operation.

Zone 2

Gas, vapour or mist

– Explosive atmosphere is unlikely in normal operation and, if it occurs, will exist only for a short time.


Zone 20

Combustible dust

– Dust is present continuously or for long periods.

Zone 21

Combustible dust

– Dust is likely to occur during normal operation.

Zone 22

Combustible dust

-Dust is unlikely in normal operation and, if it occurs, will persist only for a short time.

An ATEX code can be broken down to reveal key information such as the equipment group, category, protection method, gas or dust type, and temperature rating.
Example ATEX code:
II 2G Ex db IIB T4 Gb
Breakdown:
II – Equipment group II (intended for use in all areas except mines).
2G – Equipment category 2 for gas environments (suitable for Zone 1).
Ex – Indicates explosion protection.
db – Type of protection: flameproof enclosure.
IIB – Gas group: suitable for gases in group IIB (e.g. ethylene).
T4 – Temperature class: maximum surface temperature of 135°C.
Gb – Equipment protection level (EPL) for gases; high level of protection.

ATEX stands for ATmosphères EXplosibles, which is French for “explosive atmospheres”. It refers to two EU directives that regulate equipment and safety in environments where there is a risk of explosion from gas or dust.

ATEX is the European standard, while IECEx is the international system for certification of equipment used in explosive atmospheres. Both systems are similar, but not always interchangeable unless dual-certified.

The ‘Ex’ marking indicates that the product is designed for use in explosive atmospheres and complies with ATEX or IECEx standards. It is always followed by a series of codes that detail the exact level and type of protection.

Understanding where each ATEX zone applies is key to selecting the right equipment and ensuring safety in hazardous areas. Here are typical examples for the three gas zones:

Zone 0
An area where an explosive gas atmosphere is present continuously or for long periods.

Common examples:
– Inside fuel tanks or pipelines
– Areas with constant presence of flammable liquids or gases
– Chemical reactors with continuous gas release

Zone 1
An area where an explosive gas atmosphere is likely to occur during normal operation.

Common examples:
– Around fuel dispensing points (petrol stations)
– Near valve outlets or pump seals
– Processing areas in chemical plants where leaks may occur
– Oil and gas platforms

Zone 2
An area where an explosive gas atmosphere is unlikely to occur in normal operation and if it does, it will exist for a short period only.

Common examples:
– Rooms adjacent to Zone 1 areas
– Ventilation ducts connected to hazardous areas
– Storage areas for flammable substances
– General industrial areas with minor gas leak risks

In ATEX certification, the temperature class refers to the maximum surface temperature a piece of equipment can reach under fault and normal operating conditions. This is crucial for preventing the ignition of explosive gases or vapours in hazardous areas.

Different flammable substances ignite at different temperatures. Therefore, equipment must have a surface temperature lower than the ignition temperature of the surrounding atmosphere. The temperature class ensures that the equipment won’t become a source of ignition.

ATEX Temperature Classes (for gas environments):
T1 – Max surface temp: 450°C (e.g. hydrogen)
T2 – Max surface temp: 300°C
T3 – Max surface temp: 200°C (e.g. petrol vapour)
T4 – Max surface temp: 135°C (e.g. ethylene)
T5 – Max surface temp: 100°C
T6 – Max surface temp: 85°C (e.g. carbon disulphide)

The lower the T-class number, the safer the equipment is for use with low ignition point gases or vapours. For example, equipment with a T6 rating can be used in environments with extremely flammable gases that ignite below 85°C.

Yes, Zone 1 equipment can safely be used in Zone 2. In fact, equipment certified for Zone 1 is designed to meet a higher level of protection and can therefore be used in areas with a lower risk, such as Zone 2.

Zone classifications indicate the likelihood of an explosive atmosphere being present. Since Zone 1 has a higher explosion risk than Zone 2, any equipment certified for Zone 1 is also compliant with the safety requirements for Zone 2.

However, the reverse is not true:
Zone 2 equipment must not be used in Zone 1, as it may not provide adequate protection in more hazardous conditions.

EPL is a classification that indicates how well equipment is protected in explosive environments. Levels include Ga, Gb, Gc for gas, and Da, Db, Dc for dust. The higher the level (e.g. Ga or Da), the more robust the protection.