Introduction to ATEX 
  192-550003N10 ETH ATEX December 2019  9 
1.5.3.  Zone classification / device categories 
The table below describes the zones of an installation, where potentially explosive 
atmospheres may occur. The proprietor must analyze and assess the area, where 
explosive gas/dust mixes may occur and, if necessary, subdivide them into 
individual zones. This zone classification permits to select suitable machinery and 
equipment which can be used in this area. 
Suitable machinery and devices 
Presence of potentially 
explosive atmospheres 
Area of application   
(not mining) 
Permanently, often, for a 
long period 
approx. > 1000 h / year
 
occasionally 
approx. 10 ... 1000 h / 
year
 
rarely, for a short period, 
in the event of an error 
approx. < 10 h / year
 
* Equipment for use in areas (except underground in mining) which might be 
dangerous due to an explosive atmosphere.   
Example: 
Zon e 1
Cat egorie 2
Zone 2
Categorie
3
Zon e 0
Cat egorie 1
 
 
1.5.4.  Type of explosion protection 
In addition to category and device class, which are the minimum required 
information, the device or component designation gives additional information with 
reference to the type of protection and explosion group for gases and mists. 
The type of explosion protection defines which method or measures is/are used for 
explosion protection in given equipment or individual components. 
 
For non electric equipment, the following types of explosion protection are 
possible: