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What Are The Different Hazardous Area Classifications
Aug 27, 2019

What Are The Different Hazardous Area Classifications?

If there are any electrical equipment that are installed in an area where the equipment would come into contact with flammable liquids/gases/vapors, ignitable fibers/flyings and combustible dusts, there would be a risk for fire and explosion.

Such areas mentioned above that have possible risk due to explosive atmospheres are normally classified as hazardous areas or locations. There are 2 hazardous area classification systems that are used, depending on the country. In North America, the class/division system is used. In Europe/North America and the rest of the world, they adapt the zone system.

These systems would determine the level of protection techniques and standard of equipment which is required. We will focus on the zone system as it is used internationally and for the purposes of this article.


What is the Zone System?

Hazardous area classifications as per the Zone system are organised according to its Zone which can be sub-categorized into gas/vapors/mists and dust. For gas/dust atmospheres, the system is further divided into groups and subgroups.

For gases, vapors and mists, there are a total of 3 zones:

Zone

Level of Hazardous Material Risks

Zone 0

Where there is a presence of flammable gases or vapors that occur continuously or for long periods of time.

Zone 1

Where there is a presence of flammable gases or vapors that are generated during regular operational conditions.

Zone 2

Where presence of flammable gases or vapors are not likely to occur during regular operational conditions or, if they do occur, will exist only for a short period.


For dusts, there are a total of 3 zones as well:

Zone

Level of Hazardous Material Risks

Zone 20

Where there is a presence of combustible dusts or ignitable fibers/flyings that occur continuously or for long periods of time.

Zone 21

Where there is a presence of combustible dusts or ignitable fibers/flyings that are generated during regular operational conditions.

Zone 22

Where presence of combustible dusts or ignitable fibers/flyings are not likely to occur during regular operational conditions or, if they do occur, will exist only for a short period.


Further grouping for gas and dusts:

Group

Types of Hazardous Material and Location

Group I

Underground mines fall under this group and with firedamp present

Group II

All other hazardous areas that do not fall under Group I and are grouped for Explosive Gas

This group is further divided into 3 categories based on the type of gas:

Group A
Areas containing hexane, propane, butane, acetone, methane, petrol, benzene, paint solvents or any equivalent substitute.

Group B
Areas containing ethylene oxide, ethyl ether, ethylene, butadiene, propylene oxide, cyclopropane or any equivalent substitute.

Group C
Areas containing carbon disulphide, hydrogen, acetylene or any equivalent substitute.

Group III

This group is to categorize Explosive Dust and is further divided into 3 categories based on the type of dust:

Group A
Any area with combustible flyings.

Group B
Any area containing non-conductive dust.

Group C
Any area containing conductive dust.

Conclusion

It is important to understand hazardous area classification standards so that you can use the appropriate equipment for the right zone. Safety should be the number one priority in any hazardous workplace. Choose a partner which you can trust and rely on for your hazardous area product needs.

Supermec offers a wide range of explosion proof products, such as explosive proof lightning and explosive proof junction boxes to cater to your hazardous area classification needs. All of our products are customised to meet the strict guidelines and standards in the industry. Contact our friendly sales team at sales@supermec.com or you can drop us a call at +65 68619522 to find out more about our explosion proof solutions. Alternatively, you can visit our ecommerce platform where you can browse through the complete range of explosion proof products for various hazardous area classifications at your own time.


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