ATEX potentially explosive atmospheres

Carrying out a risk explosion assessment is a requirement indroduced by ATEX Directive 99/92/CE and transposed to the domestic legislation in EU Member states, in particular via article R4227-46 of the Fair labour standards act.

The assessment and treatment of potentially explosive atmospheres is based on :

The probability of occurrence of an explosive atmosphere,
The probability of ignition of the explosive atmosphere,
The extent of the foreseeable consequences..

Requirements

Risk explosion assessment is a requirement introduced by ATEX Directive 99/92/EC and transposed to domestic legislation in EU Member states, in particular via article R4227-46 of the Fair labour standards act.
In addition, the employer is held to subdivide into zones the areas in which explosive atmospheres can occur (article R4227-50 of the Fair labour standards act): These areas are defined in section 1 of the Decree of 8 July 2003 on the protection of workers exposed to explosion hazards:

- Flammable gases and vapours: zones 0, 1 and 2
- Combustible dust: zones 20, 21 and 22

As such, employers are obliged to formalise the assessment and classification of potentially explosive atmosphere areas (ATEX) in the document relating to protection against explosions (DRPE) (article R4227-52 of the Fair labour standards act)..

Our methodological approach

In order to assist you in setting up an explosion risk assessment initiative, the CNPP has developed the EVAREX®© method (a French acronym for explosion risk assessment), the principles and tools of which can be applied in order to obtain a structured, objective assessment of the explosion risks present within a plant. The method is implemented after the classification of the hazardous areas has been defined (commonly referred to as "ATEX zoning").

The method serves to :

Assess the explosion risks: the assessment is conducted for each risk of explosion, based on 5 parameters assessed using rating scales developed with reference to the regulation, recommendations, and feedback
Prioritise the explosion risks,
Develop corrective action and/or monitoring programmes to improve existing situations (probability, severity, penalizing factors, prevention, protection, etc.)

The EVAREX®© method is an application of the DIDERO®© occupational hazard assessment method (in response to article R.4121-1 of the Fair labour standards act) developed by the CNPP.