Not all areas of an industrial plant present the same level of risk. Some are subject to extreme conditions where a single spark could trigger a disaster. This is where ATEX zones come into play – an essential classification for anyone working in environments with combustible gases, vapours or dusts.
Choosing the right luminaire is not just a matter of regulatory compliance, but of operational safety, durability and efficiency. In this article, we explain the practical differences between the most common ATEX zones (1,2, 21 and 22) with a brief reference to zones 0 and 20 and help you identify which type of industrial lighting or ATEX luminaire is required in each case.
What are ATEX Zones and why do they matter?
The European ATEX Directive (2014/34/EU) classifies industrial areas where an explosive atmosphere may occur. Zones are defined according to the type of flammable substance (gas or dust) and the frequency of the risk:
- Zones 0, 1 and 2: risk due to gases or vapours
- Zones 20, 21 and 22: risk due to combustible dust
The lower the zone number, the higher the frequency of risk, and the more demanding the required level of protection. In every case, a certified ATEX luminaire suitable for the environmental conditions is mandatory.
Gas Zones: zone 0, 1 and 2
Zone 0: Risk of permanent presence of an explosive atmosphere. Typical examples include the interior of reactors, pipelines or tanks. Only intrinsically safe (Ex ia) or fully encapsulated luminaires are permitted, as these are highly specialized solutions.
Zone 1: Risk of frequent presence of an explosive atmosphere under normal operating conditions. Common in refineries, services stations, pumping areas or process zones. ATEX LED floodlights, flameproof projectors, IP66 enclosed luminaires and systems with Ex d or Ex e protection are used
Zone 2: Risk of an explosive atmosphere occurring infrequently or only under abnormal conditions or installation failures. Found in technical rooms, logistics or maintenance areas. ATEX tubular luminaires, linear floodlights or LED workshop lights are installed, always certified for explosive atmospheres.
Dust Zones: zone 20, 21, 22
Zone 20: permanent presence of combustible dust in suspension. Common in silos, hoppers or closed conveying systems. Requires encapsulated, IP6X-rated, flameproof lighting with materials resistant to dust accumulation.
Zone 21: frequent risk during operations such as mixing, milling, packaging or dust transport. ATEX LED sealed luminaires are used here, offering protection against dust and moisture and compatibility with high-pressure cleaning.
Zone 22: occasional risk. Found in packaging plants, laboratories, auxiliary rooms or logistics warehouses. The most common solutions include IP66 luminaires, industrial workshop lights, floodlights for fine dust or ATEX portable lamps for maintenance.
Key technical criteria for choosing the right ATEX luminaire
In addition to ATEX zone classification, the following factors must be considered:
- Ambient temperature: high – temperature processes or cold storage require luminaires designed for extreme temperature.
- Cleaning frequency: sectors such as food processing or cosmetics often require IP69K protection.
- Mounting height and accessibility: long – life LED solutions reduce maintenance interventions.
- Type of substance: gas or dust, each requiring specific protection modes (Ex db, Ex eb/ec, Ex tb/tc…)
- Lighting control systems.
An incorrect choice can result in anything from unplanned shutdowns to serious accidents.
Practical examples by sector
- In refineries, high – power ATEX floodlights with corrosion-resistant housing are used.
- In food processing plants, waterproof luminaires with total protection against dust and moisture.
- In workshops and logistics areas, IP66 linear luminaires and impact – resistant ATEX LED luminaires.
- In ATEX cold storage areas, IP69K solutions capable of withstanding high – pressure water cleaning.
Conclusion: not all industrial luminaires are suitable for ATEX zones
Understanding the differences between zones 0, 1, 2, 20, 21 and 22 is essential for installing a safe and compliant ATEX lighting system. It is not just about compliance, but about protecting assets, processes and people.
Effective ATEX lighting starts with a solid technical assessment. Because in these environments, light does more than illuminate – it prevents risks, protect operations and ensures continuity.
IVÁN CID – Engineering and innovation leader
