ATEX, UL & IECEx Guide
Please note that Radio Industries Australia Pty Ltd does not classify or take responsibility for the Hazardous Location Settings mentioned in this page, this is just a guide. Please consult your Safety Department for your exact Hazardous Location requirements.
What is Intrinsically Safe?
Intrinsically safe is a term used to describe a collection of devices and equipment that meet the requirements set out by the certification body (ATEX, UL or IECEx) to determine that device or equipment’s safety when used in a hazardous environment.
What is a Hazardous Environment?
A Hazardous Environment is an area where fumes, dust, gas or vapour may cause a fire or explosion when an ignition source is used in the area. For example, you may see a ‘No Naked Flames’ sign in your petrol station when filling up your car, this is because the area is classed as a Hazardous Environment. People who use devices like Two-Way Radios in these environments need to ensure that the device itself complies with the standard set for that particular zone. Often a safety officer will have this information to hand and be able to direct you as to what type of equipment you need for different areas of your plant.
What is the difference between ATEX, UL and IECEx?
The difference between these three is the testing/classification body.
Each rating is created by a recognised standards body with ATEX Being European, UL being American and IECEx often used for international standards. Your company may choose a specific standard to base decisions from.
ATEX Explained
Download the CML ATEX/IECEx Guide HERE – https://www.cmlex.com/wp-content/uploads/hazardous-area-guide.pdf
An ATEX Label will tell you exactly where the equipment can be used based on the Equipment classification and Zones specified. All of the numbers and letters on the label correspond to the level of protection offered and in what environments the equipment can be used. Please consult your safety supervisor for the correct equipment class you require based on the zones you are subject to.
ATEX Equipment is classified by Group, Type of protection, Gas/Dust Group, Temperature class and equipment protection level.
Areas where ATEX must be used is classified by Zones. Each Zone is for a particular Hazardous Environment. Each Zone is explained below. You will then need to use equipment suitable and certified for use the Zone.
ATEX Zones
Combustible Gas & Vapour
| Gas Zone | Description | ATEX Category | EPL | Required Protection |
| Methane | Mines with methane and dust. Equipment remains energised in explosive atmosphere. | M1 | Ma | Two Faults |
| Methane | Mines with methane and dust. Equipment is de-energised in explosive atmosphere. | M2 | Mb | Severe Normal Operation |
| Zone 0 | A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapor or mist is present continuously or for long periods or frequently. | 1G | Ga | Two Faults |
| Zone 1 | A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapor or mist is likely to occur in normal operation occasionally. | 2G | Gb | One Fault |
| Zone 2 | A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapor or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only. | 3G | Gc | Normal Operation |
Combustible Dust & Fibres
| Dust Zone | Description | ATEX Category | EPL | Required Protection |
| Zone 20 | A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently. | 1D | Da | Two Faults |
| Zone 21 | A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. | 2D | Db | One Fault |
| Zone 22 | A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only. | 3D | Dc | Normal Operation |
Equipment Groups
| Equipment Group | Description |
| Group I |
Electrical equipment intender for use in mines susceptible to fire damp |
| Group II | A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. |
| Group III | Electrical equipment intended for use in explosive dust atmospheres |
IECEx Explained
IECEx is very similar to ATEX however some of the definitions for the protection offered do differ so keep that in mind.
Download the CML ATEX/IECEx Guide HERE – https://www.cmlex.com/wp-content/uploads/hazardous-area-guide.pdf
UL Explained
UL is classified by Divisions and Classes. The classes define the substance whilst the Division defines the operating conditions. The classes are also split into subgroups to determine specific and/or equivalent substances.
Classes
- Class I – Flammable Gases, Vapours or Liquids
- Group A – Acetylene and equivalent gas groups
- Group B – Hydrogen and equivalent gas groups
- Group C – Ethylene and equivalent gas groups
- Group D – Methane, and equivalent gas groups
- Class II – Combustible Dust
- Group E – Conductive dust (mechanical – factories, recyclers)
- Group F – Combustible carbon dust (charcoal & coke dust) – above ground only
- Group G – Grain dust
- Class III – Ignitable Fibres and Flyings (No Subgroups)
Divisions
Division 1 – Locations where ignitable gas/vapor/liquid/dust are present continuously or some of the time under normal operating conditions.
Division 2 – Locations where ignitable gas/vapor/liquid/dust are not likely to exist under normal operating conditions.
Based on the above a rating of ‘Class I, Div 1, Group C, D’ would be given to an environment where Ethylene and Methane are expected to be present continuously
What equipment can I use?
There is a large range of equipment approved by ATEX, UL and IECEx. You can find the range we offer HERE – Intrinsically Safe Equipment
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