Explosion protection document

The explosion protection document (EPD) is the complete, written overview of a plant's explosion risk. It identifies the hazard sources, marks the explosive zones, evaluates the risk, and defines the preventive and protective measures together with the rules for checking them.

An important misconception to clear up: this is not a one-off record to be filed away. It is a living document that must be updated at every change affecting the explosion risk — new technology, rebuilding, a material change, or even the installation of a new extractor.

The obligation to prepare the documentation is based on the European workplace directive ATEX 153 (1999/92/EC), which aims to protect workers in explosive environments. In Hungary this is transposed by Joint Decree 3/2003 (III. 11.) FMM–ESzCsM, which regulates the minimum occupational-safety requirements of potentially explosive workplaces.

Responsibility is clear: preparing the documentation, keeping it current and carrying out its measures is the employer's duty. The general framework of fire and explosion protection is additionally set by the **OTSZ** (BM Decree 54/2014 (XII. 5.)).

The full documentation consists of several elements that build on one another. The most important:

• Zone classification and zone map — the classification of explosive spaces by the frequency and duration of the hazard, drawn on a plan.
• Explosion protection risk assessment — the systematic survey of hazard sources and risk.
• Ignition source analysis — the identification and evaluation of possible ignition sources in the zones.
• Preventive and constructive protective measures — avoiding the explosive atmosphere and ignition sources, and limiting the effects of an explosion.
• Organisational measures — training, work instructions, permit systems, maintenance and inspection plans.
• Equipment conformity — proof of the Ex marking and category of the devices used in the zones.

Each of these is a deep topic in its own right; the related pillar pages cover them in detail.

The documentation is mandatory at every workplace where an explosive atmosphere may form from flammable gas, vapour, mist or dust. Typical affected sectors: chemicals, paint and coating manufacturing, pharmaceuticals, food and mills, woodworking, waste treatment, battery-charging rooms, gas-fired facilities.

In terms of timing, the documentation must always be current: before a new installation or commissioning, at a technology change, and at every official inspection. The most common failing is not its absence but its obsolescence.

Preparing the documentation requires explosion-protection expertise: zone classification demands knowledge of the relevant standards (MSZ EN 60079-10-1 and -10-2), while the risk assessment and ignition source analysis need practical experience. Although the responsibility lies with the employer, the content is typically developed by an external explosion protection expert, who takes the process from the site survey to the finished document.

EPD table-of-contents template (PDF) — goes through point by point what a compliant explosion protection document should contain, so you can quickly check your own. Download →