Explosion Protection Document

Objective

An Explosion Protection Document (EPD or ESD) lays down the hazards and risks with respect to the occurrence of explosions within companies.

a. Inventory of workplaces, work equipment and installations:

• • Mapping out the various processes and making an inventory of the relevant workplaces and/or internal transport routes

b. Determining the ATEX danger zones

• • Based on the data obtained, the ATEX zone classification will be determined on the basis of relevant standards and guidelines. The method used for this depends on the situation/installation.

Examples of standards that can be applied are the European standard EN-IEC 60079-10 series, the EI15, API500, NFPA 497, BGR 104 or specific standards for e.g. spray booths, battery loading areas or wood dust extraction.

We often use the software tool Hazcalc for the area classification of flammable liquids and gases.

• • the zone classification is drawn (Autocad) on a plan of the location and the installations present.

c. Defining measures to limit the zones / hazardous areas

• • It shall be examined whether it is practically possible to limit the zoning (if the zoning is limited, the rules concerning the machines, equipment and electrical installations to be used will be less strict!)

d. Performing a risk analysis (ignition analysis)

• • Mapping and assessing the technical data of the installations/work equipment; the possible ignition sources in the zoned areas will be inventoried. The NEN-EN 1227-1 is used as a basis for this.
  • A risk analysis will be carried out in which the probability of the ignition of an explosive atmosphere and its possible effect will be estimated.
  • This will make a distinction between high risks and low risks.

e. Defining control measures

• • Based on the results of the risk analysis (steps a to d), the current control measures (technical/organisational) will be checked and, depending on the results, additional measures will be determined.

f. Report

• • The results of the assessments as described above, will be drawn up in an Explosion Protection Document.

On the other hand, employers should not be blinded (entirely) by the costs of drawing up an EPD. A cheap EPD is often drawn up in less time than a more expensive one. As always, it is the quality of the EPD that matters: a quick and cheap assessment often leads to fairly wide hazardous areas / ATEX zones. The reason for this, is that such an assessment (especially the determination of the zones) will be based on more assumptions and therefore “safe margins” will be maintained. This can lead to unworkable situations after the EPD has been drawn up, or too many costs being incurred in order to meet all the requirements (e.g. replacement of electrical installations, drawing up work procedures and instructing employees). By spending more time on a proper assessment and determination of the zones, unrealistic measures and excessive costs can be avoided in the follow-up phase.

In the past 15 years, we have made assessments and Explosion Protection Documents (EPD’s) for many companies in various branches. Examples include water waste treatment plants (biogas), paint shops, pharmacy, wood processing, chemistry, automotive, bulk storage and transport, animal feed industry, etc.

Our working method is characterised by a practical approach with clear and unambiguous assessments. We are particularly critical in determining the hazardous areas. This is the first important step in determination of the potential explosion hazards. When hazardous areas can be avoided (or can be prevented with relatively simple measures!), no further measures (and therefore no costs) need to be taken to reduce explosion risks.