ATEX Ratings Explained
Working in hazardous or explosive environments demands the highest levels of safety and compliance. ATEX ratings provide the essential framework that governs how equipment can be designed, certified, and used in potentially explosive atmospheres. At Comtherm, we supply a wide range of ATEX rated motors and ATEX approved differential pressure switches to ensure compliance and operational safety across industries.
What is ATEX?
ATEX (short for Atmosphères Explosibles) refers to two European Union directives that regulate equipment and workplace safety in explosive atmospheres:
- ATEX 99/92/EC – The Workplace Directive, which protects employees working in hazardous areas.
- ATEX 2014/34/EU – The Equipment Directive, which governs the design and certification of equipment used in explosive atmospheres.
Together, these directives ensure that both the working environment and the equipment installed meet strict safety standards.
Where Are ATEX Products Used?
ATEX certified equipment is essential in industries where explosive atmospheres may occur. Typical applications include:
- Chemical and petrochemical plants – handling volatile gases and solvents
- Oil and gas operations – refineries, offshore platforms, and pipelines
- Food and beverage processing – facilities where dust from flour, sugar, or grain can become combustible
- Paint finishing and automotive plants – spray booths and coating systems
- Pharmaceutical and chemical manufacturing – handling fine powders and vapours
ATEX Zone Classifications
Zones are defined according to how frequently and for how long an explosive atmosphere is present. Correct classification is crucial when selecting compliant equipment.
Gas, Vapour and Mist Zones
- Zone 0: Explosive atmosphere present continuously or for long periods.
- Zone 1: Likely occurrence of explosive atmosphere during normal operation.
- Zone 2: Explosive atmosphere not likely, or only present for short durations.
Dust Zones
- Zone 20: Combustible dust present continuously or for long periods.
- Zone 21: Combustible dust likely to occur occasionally during normal operation.
- Zone 22: Combustible dust not likely, or only present for short durations.
ATEX Equipment Groups and Categories
Equipment is divided into groups and categories based on the type of environment where it will operate:
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Group I – Mining
- Category M1: Remains operational in explosive atmospheres.
- Category M2: De-energises when explosive conditions occur.
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Group II – Non-mining industries
- Category 1: For Zone 0/20 (highest protection).
- Category 2: For Zone 1/21 (high protection).
- Category 3: For Zone 2/22 (normal protection).
ATEX Markings and Temperature Classes
All ATEX equipment is marked with a code that specifies its certification. This marking provides information on the group, category, zone suitability, and maximum surface temperature. Temperature classes are defined as:
- T1: Max surface temperature 450°C
- T2: Max surface temperature 300°C
- T3: Max surface temperature 200°C
- T4: Max surface temperature 135°C
- T5: Max surface temperature 100°C
- T6: Max surface temperature 85°C
Selecting the correct temperature class ensures that the equipment cannot ignite the gases, vapours, or dusts present in a specific zone.
ATEX vs IECEx
While ATEX certification is mandatory across the European Union, the IECEx scheme provides a globally recognised standard for explosive atmosphere equipment. Many manufacturers obtain both certifications to cover worldwide markets, ensuring safety and compliance wherever the equipment is used.
European Compliance Requirements
Organisations within the EU must comply with ATEX directives. This involves:
- Conducting risk assessments of potential explosive atmospheres.
- Classifying work areas into the correct ATEX zones.
- Selecting and installing equipment with the appropriate ATEX category rating.
- Maintaining safety documentation and carrying out regular audits.
Failure to comply can result in legal penalties and, more importantly, increased risks to people and assets.
Choosing the Right ATEX Equipment
When specifying ATEX equipment, it is essential to match the product to the zone classification and temperature class of your environment. For example, a motor intended for a Zone 21 dust environment should meet Group II, Category 2D standards, with the appropriate temperature rating to prevent ignition of dust clouds. Our ATEX motors and pressure switches are designed and certified for exactly these conditions.
Conclusion
Understanding and applying ATEX ratings is essential for any industry working with hazardous gases, vapours, or dust. By selecting the right certified equipment and maintaining strict compliance with European guidelines, businesses can protect both people and operations. For technical support or to source ATEX-rated components, explore our range of motors and switches, or speak with the Comtherm team today.
Disclaimer: This article is for informational purposes only and should not be considered legal or compliance advice. Always consult qualified specialists for ATEX risk assessments and equipment approval.