Places in the presence of flammable vapors or gases .

These possible formation of explosive atmospheres at any time , for example, the areas of transfer of liquid explosives, paint booths , storage of solvents , etc. .
Are subdivided according to the probability of the presence of explosive atmosphere :

  • Zone 0 : permanent presence or for extended periods of time.
  • Zone 1 : capable of forming in normal working conditions .
  • Zone 2 : presence unlikely and short periods .

Security principles to consider are:

  • Explosion risk areas should be as small as possible.
  • The presence of electrical equipment will be minimized and will be protected in accordance with the area.

Places in the presence of combustible dust .

As an example we can mention grain silos , mills , coal processing plants , fertilizer plants , etc. .

Within this class are distinguished :

  • Area 20 : It is one in which there is or may have combustible dust operations during normal operation , start-up or cleaning , in sufficient quantity to produce an explosive atmosphere . Example: in mills sprayers .
  • Area 21 Is that where the cloud or dust layer is likely to form in normal working conditions .
  • Area 22 : presence unlikely and short periods .