How often must an Explosion Protection Document be reviewed or updated?
Abstract
There is no fixed interval in years. Directive 1999/92/EC requires the EPD to be revised after significant changes and the protection measures to be reviewed regularly; DSEAR and Türkiye's rules are similar. Many operators review the EPD yearly and after incidents.
The ATEX workplace directive 1999/92/EC sets no review interval in years. The Explosion Protection Document (EPD) must be kept up to date and revised whenever the workplace, the work equipment or the organisation of work undergoes significant changes, extensions or conversions. The explosion protection measures it describes must also be reviewed regularly. Great Britain's DSEAR likewise requires the risk assessment to be reviewed regularly. In Türkiye the general risk assessment it belongs to has maximum renewal periods by hazard class. Most operators add a planned periodic review, often yearly, and a review after every incident.
Short answer
- EU directive: Article 8 of 1999/92/EC requires the EPD to be revised on significant change and fixes no period in years. Article 3 requires the explosion prevention and protection measures to be reviewed regularly and whenever significant changes occur.
- Great Britain (DSEAR regulation 5(3)): review regularly to keep the assessment current, and in particular when there is reason to suspect it is no longer valid or after a significant change.
- Türkiye: the 2013 explosive atmospheres regulation requires the measures to be reviewed at regular intervals and after significant changes (Article 5), and the document to be updated after significant change, extension or modification (Article 10). The ministry guide lets the preparing team set its own review period. The general risk assessment regulation sets renewal at the latest every 2, 4 or 6 years for very hazardous, hazardous and less hazardous workplaces.
- Good practice: a scheduled review (yearly is common), plus reviews after incidents, near misses and inspection findings, built into management of change.
What triggers a revision
The legal trigger is a "significant change". The law does not list what counts, so the employer must decide case by case. A change is significant when it could alter where an explosive atmosphere forms, how often, how large it is, or which ignition sources are present. Typical triggers are shown below.
| Trigger | Why it matters |
|---|---|
| New or different substance, or a new supplier of the same product | flash point, gas group, temperature class or dust properties may change |
| New equipment, process step or higher throughput | new sources of release, larger release rates |
| Layout or building changes (walls, roofs, enclosures, acoustic hoods) | ventilation and the zone extent change |
| Changes to ventilation, inerting, gas detection or interlocks | the zone type may rest on these measures |
| Change in the organisation of work (unmanned shifts, new contractors) | coordination and organisational measures change |
| Incident, near miss, or leaks larger or more frequent than assumed | the assumptions behind the zones were wrong |
| Ex inspection finds the plant does not match the drawings | the document no longer describes reality |
| New standard edition or new technical knowledge | the state of the art moved on |
The Turkish ministry's risk assessment leaflet lists similar triggers for the general risk assessment: a work accident, occupational disease or near miss; relocation or building changes; new technology, substances or equipment; new production methods; changed legislation; and new risks found through measurements or health surveillance.
Why a fixed interval is still useful
Change-driven review works only if somebody notices the change. Small changes add up: a second pump, a new drum store, a fan that is switched off at night. A scheduled review catches what management of change missed. Guidance from two prevention sections of the International Social Security Association (ISSA) also says the protective measures must be adapted when the state of the art develops, not only after plant changes.
EU and Great Britain. Directive 1999/92/EC (Article 3, for the measures) and DSEAR (for the risk assessment) both ask for regular review in addition to change-driven review. Neither states the interval, so the employer sets one that fits the plant.
Türkiye. The 2013 regulation (Çalışanların Patlayıcı Ortamların Tehlikelerinden Korunması Hakkında Yönetmelik) asks for review "at regular intervals" but sets no interval in years. The explosion risk assessment is carried out under the general Occupational Health and Safety Risk Assessment Regulation (İş Sağlığı ve Güvenliği Risk Değerlendirmesi Yönetmeliği). That regulation requires renewal at the latest every 2 years for very hazardous (çok tehlikeli), 4 years for hazardous (tehlikeli) and 6 years for less hazardous (az tehlikeli) workplaces. The explosive atmospheres regulation does not link the two cycles explicitly. Reviewing the explosion protection document at least whenever the general risk assessment is renewed keeps the two consistent.
Example: A paint factory's EPD was last reviewed in March. In June a new filling line is added and a solvent is replaced with a cheaper one that has a lower flash point. Both are significant changes, so the area classification and the equipment list are reviewed before the line starts, not at the next annual review. In October an Ex inspection finds two non-Ex junction boxes inside Zone 2. The finding is corrected, and the EPD is checked to see whether the drawing or the installation was wrong.
How to organise the review
- Document control: keep a revision table with the date, the reason, the sections changed and the approver.
- Link to management of change: every change request asks one question: "Does this affect the EPD?"
- Link to inspections: feed the findings of Ex inspections under IEC 60079-17 back into the document.
- Short-term work: maintenance and temporary activities are normally handled by permit-to-work and a task risk assessment, not by rewriting the EPD.
- Who signs: the employer owns the document and approves each revision, even if a consultant writes it.
Common mistakes
- Waiting for the annual review when a significant change is planned. The revision must come before the change takes effect.
- Updating the text but not the drawings. The zone drawings and the equipment register are part of the EPD.
- Assuming "no fixed interval" means "never". A document that has not been checked for years rarely matches the plant.
- Forgetting organisational changes. New contractors, reduced staffing or unmanned operation can change the measures even when nothing physical changes.
Related on excodex
- The Explosion Protection Document (EPD) and area classification drawings under ATEX 1999/92/EC
- Is an Explosion Protection Document mandatory for small companies?
- Which workplaces in Turkey must prepare an explosion protection document?
- Inspection of Ex installations under IEC 60079-17
- Standards spaces: Directive 1999/92/EC, IEC 60079-17
Standards and further reading
- Directive 1999/92/EC, Article 3 (review of prevention and protection measures): legislation.gov.uk; Article 8 (explosion protection document): legislation.gov.uk
- Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR), regulation 5 on risk assessment and its review: legislation.gov.uk
- Turkish regulation on protecting workers from explosive atmospheres, Resmî Gazete 30.04.2013, No. 28633, Articles 5 and 10: adalet.gov.tr
- Ministry of Labour and Social Security, implementation guide on protecting workers from explosive atmospheres (in Turkish): csgb.gov.tr
- Ministry of Labour and Social Security, leaflet on risk assessment with renewal periods and triggers (in Turkish): csgb.gov.tr
- ISSA, practical assistance for preparing an explosion protection document (2nd edition, 2024): safety-work.org
- IEC 60079-17, inspection and maintenance of electrical installations in explosive atmospheres.
This article is general technical information prepared by the excodex editorial team. It does not replace the applicable standards, the equipment certificates and instructions, national regulations or the assessment of a competent person.