Explosion protection according to ATEX - Avoiding explosions in the chemical and pharmaceutical industry

ATEX is an abbreviation for the French term "ATmosphères EXplosibles". It can be found in the Directive 2014/34/EU of the European Union, which determines the legal basis for the use of equipment and protection devices in areas with potentially explosive atmospheres.
In all industrial sectors, including the chemical and pharmaceutical industries, it is necessary to comply with strict regulations and to eliminate hazards to such an extent that an explosion is at best excluded. In the following, we have provided an overview of what the ATEX Directive and the regulations derived from it mean for your company

Excursus: When do explosions occur?

Explosions in the industry are a present hazard whenever explosive substances and mixtures are used. These substances and mixtures can be solid, liquid or gaseous. The conditions that must be fulfilled for an explosion to occur are illustrated in the hazard pentagon.

Estimating the hazard of explosions: The hazard pentagon

The hazard pentagon shows all components needed for an explosion to take place. If these are present at the same time, an explosion may occur. If, on the other hand, only one of the five conditions is missing, the danger of explosion is no longer present.

To assess the risk and effects of an explosion in principle, the substances used are assessed by means of explosion parameters. These are important in order to make decisions regarding protection measures and usable equipment that is located in the hazardous area.

Explosion parameters should help to assess the explosion hazard. In the process, there are a wide variety of numbers to be observed. For dust, the most important explosion parameters can be found in the overview. 

Classification in ATEX zones

Production sites and systems with potentially explosive atmospheres are classified into Ex protection zones (ATEX zones), which are specified in the explosion protection document. This classification of zones is carried out on the one hand by the manufacturer of the systems and equipment, and on the other hand by the operator of the production facilities in which the systems are deployed. There are both dust and gas Ex zones, depending on the composition and duration of occurrence of explosive substances and mixtures, as well as groups and categories for the assessment of the equipment. These determine the respective requirements for the protection measures needed in the individual areas. We have dedicated a separate blog article to the differences and the assignment of the equipment categories to the ATEX zones.

What needs to be observed when working with the specifications from the ATEX Directive?

In order to guarantee the highest possible safety standards for employees and for the plant or system not only from the legal side, there are various ATEX regulations and guidelines that must be observed. A differentiation is made here between the directives for the operator of the equipment with potentially explosive atmospheres and for the manufacturer of this equipment. There are European and national directives and regulations, which both must be observed.

If potentially explosive atmospheres are present, special caution must be exercised! Plant operators and manufacturers can protect employees and equipment not only by observing the legal requirements. Further protection measures can be taken, that can be both preventive and constructive. Preventive protection measures are available to avoid explosions, but there are also constructive protection measures to minimize damage to the equipment.

Summary

Explosions can occur as soon as combustible substances come into contact with reaction products. Industries and production areas with increased probability of explosions must take protection measures based on legal requirements. Some measures apply for the system operator and some for the system manufacturer. In order to take suitable protection measures for operation and equipment, explosion parameters must first be determined. These parameters, in connection with the respective ATEX zones, help to protect the hazardous area as best possible against an undesired explosion.