arpadveress 
According ATEX 137 employer of hazardous area industries shall define the Ex safe operation latest at the time very first day of operation. Here all aspects of Ex safe operation shall be considered, and if there is any change the EPD shall be updated. Within at least 3 years the renewal shall happen again (it has to be documented).
Training of EPD to employees but subcontractors too shall be done and documented in regular basis.
The ATEX regulation says the following:
a) All necessary measures must be taken to ensure that the workplace, work equipment and any associated connecting device made available to workers have been designed, constructed, assembled and installed, and are maintained and operated, in such a way as to minimise the risks of an explosion and, if an explosion does occur, to control or minimise its propagation within that workplace and/or work equipment. For such workplaces appropriate measures must be taken to minimise the risks to workers from the physical effects of an explosion.
b) Where necessary, workers must be given optical and/or acoustic warnings and withdrawn before the explosion conditions are reached.
Which means the EPD declares the Ex safe operation as it is. Any modification shall be immediately recorded, accordingly the documentation shall be updated.
Gas warning systems, plus optical and acoustic signal equipments to have in place is mandatory. All Ex (according to EPL). All functional.
So to come to this stage of Ex safe operation: URS – design including hazardous area classification with resulting EPL (equipment protection level) – installation – commissioning – Ex inspection with all necessary Ex personnel competence is a must have. Otherwise all above cannot be fully listed and displayed in an EPD of said facility.
Can we call it Ex design chapter? Or simply Verification Dossier makes it all? Good question. Anyway the responsibility of EPD is with the owner of possible hazardous environment. Test application makes no difference – same level of EPD shall be there in place.
Keep up good work!
Arpad
