Explosion protection document in Germany: contents, zoning and inspections

What is an explosion protection document?

The explosion protection document (Explosionsschutzdokument) is the part of the risk assessment (Gefährdungsbeurteilung) in which the employer sets out the hazards from hazardous explosive mixtures separately – with the assessment, the explosion protection concept, zoning, protective measures and inspections. The legal basis is Section 6 (9) of the Hazardous Substances Ordinance (Gefahrstoffverordnung, GefStoffV). Because it is part of the documentation under Section 6 (8), it must exist before work first starts – regardless of the number of employees.

Typical areas are paint shops, solvent stores and filling stations, woodworking with dust extraction, and mills, silos and mixing plants for flour, sugar or plastic powders. According to TRGS 721, an explosion with dangerous effects is possible when four conditions coincide:

• flammable substances, finely dispersed as gas, vapour, mist or airborne dust
• a concentration in air within the explosion limits
• a dangerous quantity
• an effective ignition source

When is an explosion protection document required?

Whether you need an explosion protection document follows from the assessment of fire and explosion hazards under Section 6 (4) GefStoffV. TRGS 720 sets out the order of the assessment:

1. 1

   Flammable substances present?

   Check whether flammable gases, liquids or dusts are present or can be formed – including during start-up and shutdown, cleaning or faults. If not, record this in the risk assessment.

2. 2

   Explosive atmosphere possible?

   Dispersion and concentration are decisive: for liquids, for example, when they are sprayed or their flash point is not sufficiently above the processing temperature; for dusts, when they are stirred up.

3. 3

   Substitution possible?

   If only substances that cannot form an explosive atmosphere are used – such as water-based systems instead of solvents – no explosion protection measures are needed. This is documented too.

4. 4

   Reliably prevented?

   If tightness, natural ventilation or organisational measures such as removing dust deposits already reliably prevent hazardous explosive atmospheres, a note in the risk assessment is sufficient. If active measures such as technical ventilation or gas detectors are needed for this, or a hazard remains, you need an explosion protection concept and the explosion protection document.

What goes into the explosion protection document?

Section 6 (9) GefStoffV specifies what the document must show in particular:

• that the explosion hazards have been identified and assessed
• the explosion protection concept, i.e. the precautions taken to achieve the aims of explosion protection
• whether and which areas have been classified into zones
• for which areas explosion protection measures under Section 12 and Annex I No. 1 GefStoffV have been taken
• how cooperation with contractors under Section 15 GefStoffV is implemented
• which checks under Section 7 (7) GefStoffV and which inspections under Annex 2 Section 3 of the Ordinance on Industrial Safety and Health are to be carried out

The ordinance does not prescribe a format. The structure of DGUV Information 213-106 “Explosion protection document” (Explosionsschutzdokument) has proven useful: plant section and responsible person, building conditions, process description, substance data with safety parameters such as flash point, explosion limits and ignition temperature, the assessment of where hazardous explosive mixtures can form, and the explosion protection concept with zones and technical and organisational measures.

Zoning: zones 0, 1, 2 and 20, 21, 22

Hazardous areas are classified into zones according to how often and how long a hazardous explosive atmosphere occurs – zones 0 to 2 for gases, vapours and mists, zones 20 to 22 for combustible dusts (Annex I No. 1.7 GefStoffV). The zone determines which equipment may be used there (Annex I No. 1.8):

• Zone 0 (gases) / Zone 20 (dusts)

  A hazardous explosive atmosphere is present …continuously, for long periods or frequently

  Equipment categoryCategory 1

• Zone 1 / Zone 21

  A hazardous explosive atmosphere is present …occasionally in normal operation

  Equipment categoryCategory 1 or 2

• Zone 2 / Zone 22

  A hazardous explosive atmosphere is present …not normally in normal operation, and if it does occur, only rarely and for a short time

  Equipment categoryCategory 1, 2 or 3

Normal operation means operation within the design parameters. If in doubt, the stricter zone applies, and dust layers and deposits must be considered like any other source of explosive atmosphere. Mark the entrances with the warning sign “Warning: explosive atmosphere” (Annex I No. 1.6 (5)); smoking, open flames and access by unauthorised persons must be prohibited there (Annex I No. 1.3 (2)).

Explosion protection concept: protective measures in three stages

The protective measures follow the order of priority in Section 12 (2) GefStoffV; the details are described in TRGS 722 to 725:

• Avoid or limit hazardous explosive mixtures (TRGS 722): substitutes with a high flash point, limiting concentrations, inerting, tight installations, ventilation and extraction, removing dust deposits
• Avoid effective ignition sources (TRGS 723): equipment suited to the zone, earthing and equipotential bonding, protection against electrostatic charging (TRGS 727), banning open flames, permit procedures for hot work
• Limit the effects of an explosion (TRGS 724): explosion-resistant design, explosion venting, explosion suppression and explosion isolation

TRGS 723 lists 13 types of ignition source – including hot surfaces, flames and hot gases, mechanically generated sparks, electrical installations, static electricity, lightning and chemical reactions. For each relevant ignition source, you assess whether it can become effective in normal operation, in foreseeable malfunctions or only in rare malfunctions, and document this in the explosion protection document. Where protective measures depend on measuring, control and regulating devices such as a gas detection system, TRGS 725 applies to their reliability.

Which inspections belong in the explosion protection document?

The explosion protection document specifies which inspections are required. For installations in hazardous areas and the related protective measures, Annex 2 Section 3 of the Ordinance on Industrial Safety and Health (Betriebssicherheitsverordnung, BetrSichV) applies:

• Installation before first commissioning and after modifications requiring inspection (No. 4.1)

  Intervalbefore (re)commissioning

  Who inspectsapproved inspection body (zugelassene Überwachungsstelle, ZÜS) or person qualified to carry out inspections with special qualifications under No. 3.3

• Installation periodically for explosion safety (No. 5.1)

  Intervalat least every 6 years

  Who inspectsZÜS or qualified person under No. 3.3

• Equipment, protective systems, safety, control and regulating devices (No. 5.2)

  Intervalat least every 3 years

  Who inspectsperson qualified to carry out inspections under No. 3.1

• Ventilation systems, gas detection systems, inerting systems (No. 5.3)

  Intervalannually

  Who inspectsperson qualified to carry out inspections under No. 3.1

• Function and effectiveness of technical protective measures (Section 7 (7) GefStoffV)

  Intervalat least every third year

  Who inspectsarranged by the employer, result recorded

For installations requiring a permit under Section 18 (1) Nos. 3 to 7 BetrSichV – such as storage facilities for more than 10,000 litres of flammable liquids with a flash point below 23 °C, filling points and petrol stations – only the ZÜS may carry out the inspections under Nos. 4.1 and 5.1. Instead of the periodic inspections under Nos. 5.2 and 5.3, the employer may set out an equivalent maintenance concept, whose suitability is assessed in the inspection before commissioning (No. 5.4).

When do you need to update the explosion protection document?

Like the risk assessment as a whole, the explosion protection document must be reviewed regularly and updated without delay when significant changes or new information require it (Section 6 (10) GefStoffV). You set the review intervals to suit your company. Typical reasons for an update:

• new or changed substances, quantities, processes or work equipment
• conversions or changes to installations in the hazardous area
• new findings, in particular from accidents and incidents
• inspection results showing that protective measures are not effective or not sufficient

If a review shows no need for changes, record this with the date. A revision sheet with the date, amended section, change and signature makes the current status traceable for inspectors and authorities.

Checklist: explosion protection document

• Flammable substances and activities recorded – including cleaning, maintenance and faults
• Safety parameters taken from safety data sheets or databases
• Substitution with substances that cannot form explosive mixtures checked
• Areas with hazardous explosive atmospheres defined and, where sensible, classified into zones
• Equipment and work equipment selected to suit the zone
• Ignition sources assessed and measures defined
• Entrances marked, smoking ban and ban on unauthorised access in place
• Instruction, operating instructions and permit-to-work system arranged
• Inspections under BetrSichV and Section 7 (7) GefStoffV scheduled with intervals
• Document completed before work starts, review date set

Free templates for this guide

As PDF and Excel, free – to use in your own company.

• Hazardous substances

  Explosion protection document template (PDF & Excel) with zone register

  PDF + ExcelFree download

Frequently asked questions