1- What is an explosive atmosphere?
2- Is a flammable substance explosive atmosphere in any condition?
3- Then, a liquid is not considered explosive atmosphere?
4- What directives control explosive atmospheres?
5- Should we identify and indicate areas with potentially explosive atmospheres?
6- What kind of measures should be taken into account in these areas?
7- Would it be enough to check with detection equipment that there is no explosive atmosphere when working?
8- What elements it affects?
9- Is normal, made in steel, tool ignition source?
10- So, I never can use it in hazardous areas?


1- What is an explosive atmosphere?

It is a mixture that flammable substances (in the form of gases, vapours, mists or dusts) form with air, in which; after ignition has occurred combustion spreads to the entire unburned mixture.

2- Is a flammable substance explosive atmosphere in any condition?
No, it is not. Sufficient air and substance mixture must exist. Each substance has a minimum and maximum percentage of air (oxygen) required, out of which combustion does not undergo, and therefore is not considered explosive atmosphere.

3- Then, a liquid is not considered explosive atmosphere?
The liquid itself is not an explosive atmosphere. But all liquid vapours generated on its surface, which when mixed with air, can result in an explosive atmosphere.

4- What directives control explosive atmospheres?
ATEX is the name given to the European Directives for controlling explosive atmospheres, more specifically, Directive 1999/92 / EC and the corresponding approximation of the laws of Member States and finally other European standards for prevention.

5- Should we identify and indicate areas with potentially explosive atmospheres?
Yes, it is necessary to classify areas according to the likelihood where hazardous explosive atmospheres may occur. Usually it classified as Zone 0 for gases or 20 for dusts, if an explosive atmosphere is present for periods of more than 1000 hours per year. Zone 1 (or 21) indicates the place, in which an explosive atmosphere is likely to occur between 10 and 1000 hours per year. Zone 2 indicates the place in which the explosive atmosphere persists between 0.1 hours (6 minutes) and 10 hours a year. If this period is shorter, then there is no need to classify the area.

6- What kind of measures should be taken into account in these areas?
The directive states that all potential ignition sources must be avoided, but if it is not possible, they should be at least reduced and in this case, it is important to take measures to mitigate the detrimental effects of possible deflagration.

7- Would it be enough to check with detection equipment that there is no explosive atmosphere when working?
No, it is not enough. It is compulsory to do so, as well as to provide all possible measures to eliminate all foreseeable risk. Nevertheless, it is important to highlight that according to the law all necessary safety measures need to be taken no matter if any explosive atmosphere is present or not in a certain moment. If the zone is ATEX classified, there must be used all means in order to avoid or reduce ignition sources and mitigate the consequences of an explosion.

8- What elements it affects?
To all those likely to generate spark, such as: machines, devices, clothing and tools, among others.

9- Is normal, made in steel, tool ignition source?
Yes, it is, according to Directive 1999/92 / EC and EN 1127.

10- So, I never can use it in hazardous areas?
In accordance with the directive, you cannot. In this case non-sparking (safe) tools should be used. EN 1127 norm specifies that you can never use any steel tool in Zones 0, 20 or 1, 21,2,22 if the atmosphere is a gas listed in the IIC group. You also cannot use steel tools in areas 1, 21,2,22 in atmospheres of other groups if its normal use generates sparks (hammers, files, saws, etc.).