ATEX Zone Classification Chart FREE PDF
Learn how the ATEX classification chart guides hazardous zone identification.
Get the Free PDF – ATEX Zone Classification Chart
Understand how ATEX zones are classified based on the presence and persistence of explosive atmospheres in industrial workplaces. This chart explains Zones 0–2 and 20–22 according to Directive 1999/92/EC, considering the hazardous atmosphere itself, before any mitigation measures such as inerting or ventilation are applied.
🔗 Useful External Links
AIChE – Chemical Engineering Progress (CEP)
Monthly journal by the American Institute of Chemical Engineers, featuring best practices in process design, optimization, and plant operation.
OSHA – Process Safety Management Guidelines
Official U.S. resource outlining key safety requirements for chemical and industrial plants.
Chemical Engineering Magazine (ChemEngOnline)
Leading publication covering industrial case studies, plant optimization, and process technologies.
Engineering Toolbox
Comprehensive database with thermodynamic properties, process diagrams, and equipment data for engineers.
Perry’s Chemical Engineers’ Handbook – McGraw Hill
The standard reference for chemical and process engineers worldwide, covering theory, design, and safety.
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FAQ
What does ATEX stand for?
ATEX refers to two European Union directives that regulate equipment and safety in explosive atmospheres. The name comes from the French phrase for “Explosive Atmospheres,” but it’s commonly used in all EU languages as a technical term.
How often should ATEX zones be reviewed?
ATEX classifications must be reviewed whenever a change occurs in the plant layout, ventilation, process conditions, or substances handled. Even minor modifications can alter zone boundaries or risk levels.
Does nitrogen blanketing affect ATEX zone classification?
No. The presence of inert gas like nitrogen reduces the risk of ignition, but ATEX zoning is based on the presence and release of flammable substances, not on control measures. Blanketing is considered later during ignition risk analysis, not during zone definition.
Is ATEX zoning mandatory in non-EU countries?
ATEX is an EU regulation, but many countries outside the EU adopt similar standards or refer to IECEx. Multinational companies often align with ATEX to maintain consistency in their explosion protection strategies.
Can dust and gas zones coexist in the same area?
Yes. If both combustible dust and flammable gas are present in a process, overlapping zoning may apply, for example, Zone 1 for gas and Zone 21 for dust. This situation is common in units handling partially dried solids or organic powders. A typical case is the discharge of low-moisture product from a centrifuge or the feeding of a dryer. Equipment in such areas must be certified for both types of explosive atmospheres.
Why is the ATEX classification chart useful?
The ATEX classification chart helps engineers and safety professionals quickly identify zone types and their associated requirements, based on EU Directive 1999/92/EC.
It serves as a practical reference during design, inspections, and risk assessments, especially in early plant layout stages.
Even when inerting systems are used, the chart still applies, because inerting influences the ignition risk, not the classification of the area itself.