What competence does a person need to carry out a hazardous area classification?
Abstract
Usually no specific licence. The classifier must know the flammable substances, the process and equipment, the release and ventilation method of IEC 60079-10-1 and the law, and usually works in a team. IECEx unit Ex 002 offers a voluntary certificate.
Generally no specific licence is required (neither the EU workplace directive, UK DSEAR nor the Turkish regulation names one), but the work must be done by people who are competent for it. That means knowing the properties of the flammable substances, the process and its equipment, the release and ventilation method of IEC 60079-10-1 (and IEC 60079-10-2 for dusts) and the legal framework, with enough experience to judge real plants. Classification is usually a team task, and the IECEx scheme offers a voluntary certificate for it: unit Ex 002, "Perform classification of hazardous areas".
Short answer
- The legal duty to classify lies with the employer (Directive 1999/92/EC and national laws such as UK DSEAR or the Turkish 2013 regulation). The law asks for competence, not for a named profession.
- The standard's view: IEC 60079-10-1 has long said classification should be carried out by people with knowledge of the properties of flammable materials, the process and the equipment, in consultation with safety, electrical, mechanical and other engineering staff. The 2020 edition has a dedicated subclause on competence of personnel.
- Typical knowledge: substance data, grades of release and release rates, ventilation and dispersion, zone types and extents, industry codes, dusts, and the consequences for equipment selection.
- Team: process or chemical engineer, operations and maintenance, safety specialist, electrical and instrument engineer, led by someone experienced in classification.
- Proof of competence: a track record and training; the IECEx Certificate of Personnel Competence (CoPC) for unit Ex 002 is one recognised, voluntary way to demonstrate it.
What the person or team needs to know
| Area | What it covers in practice |
|---|---|
| Substances | Flash point, lower and upper flammable limits, vapour density, autoignition temperature, gas group and temperature class; dust properties for dust zones |
| Process and equipment | Operating pressures and temperatures, normal operation including start-up and shutdown, maintenance practices, where and how leaks happen |
| Method | Sources and grades of release, release rate calculations, degree of dilution and availability of ventilation, zone type and extent (IEC 60079-10-1; IEC 60079-10-2 for dust) |
| Codes and data | Industry codes and examples where they fit (for example EI 15 or API RP 505), and when they do not |
| Consequences | Equipment protection levels and categories that each zone requires, ignition source control, documentation in the explosion protection document |
| Law | The employer's duties under 1999/92/EC or the national equivalent, verification before first use, review after changes |
HSE's technical guidance for inspectors lists what a classification study should document: the flammable materials and their properties, the sources of release, the ventilation, the dispersion and the likelihood of each release scenario. A competent classifier can produce and defend each of those items.
Why it is usually a team
No single person normally knows the chemistry, the operating history, the maintenance reality and the electrical consequences of a plant. The 2002 edition of IEC 60079-10 already expected classification by people who know the materials, in consultation with safety, electrical, mechanical and other engineering personnel. It also said that once a plant is classified, changes should not be made without consulting those responsible for the classification, and that reviews should continue during the life of the plant. The Turkish Ministry's application guide similarly expects all responsible persons to take part in preparing the explosion protection document, and asks for calculations from the relevant standards and literature rather than assumptions.
How competence can be shown
- IECEx CoPC Ex 002. The IECEx scheme lists units Ex 000 to Ex 011; Ex 002 is "Perform classification of hazardous areas". Candidates pass a knowledge assessment and, for this unit, a practical assessment in which they classify a gas area and a dust area. Experience is part of the competence definition, and re-assessment is on a five-year cycle.
- Training and experience records in an employer's competence management system, including supervised classifications.
- Professional engineering qualifications in process, chemical or electrical engineering, plus specific area classification training.
- Independent review of the drawings and the reasoning by a second competent person, which catches most errors.
A note for Turkish readers
The Turkish Regulation on the Protection of Workers from the Hazards of Explosive Atmospheres (Çalışanların Patlayıcı Ortamların Tehlikelerinden Korunması Hakkında Yönetmelik, Official Gazette No. 28633, 30 April 2013) makes the employer classify hazardous places (Article 9) and prepare the explosion protection document (Article 10). It does not reserve the work for a named profession. Its Annex 2 requires the explosion safety of the workplace to be verified by competent persons trained and/or experienced in explosion protection. More detail is in who can prepare an Explosion Protection Document in Turkey.
Common mistakes
- Leaving classification to the electrical contractor alone. Classification is a process safety task; the electrical team applies its result.
- Copying a typical drawing from another plant without checking release rates, ventilation and substances.
- Treating a short course as sufficient without supervised experience on real installations.
- No review after modifications. A competent classification goes out of date when the process, the ventilation or the layout changes.
Related on excodex
- How to carry out a gas hazardous area classification step by step (IEC 60079-10-1)
- The Explosion Protection Document (EPD) and area classification drawings under ATEX 1999/92/EC
- Who is legally responsible for hazardous area classification under ATEX?
- Competence of people working in hazardous areas: IECEx CoPC
- Standards spaces: IEC 60079-10-1, IECEx, ATEX 1999/92/EC
Standards and further reading
- IEC 60079-10-1:2020, classification of areas, explosive gas atmospheres (subclause on competence of personnel): preview; 2002 edition general clause: preview
- IEC 60079-10-2, classification of areas, explosive dust atmospheres
- IECEx, certification bodies for personnel competence and the units (Ex 000 to Ex 011) each one covers: iecex.com; IECEx Secretariat presentation of the CoPC scheme (2017), with the Ex 002 practical assessment: PDF
- Directive 1999/92/EC, Articles 7 and 8 and Annex II: legislation.gov.uk (PDF)
- HSE, technical measures document on hazardous area classification: hse.gov.uk
- Regulation on the Protection of Workers from the Hazards of Explosive Atmospheres (Turkey), Official Gazette No. 28633, 30 April 2013: resmigazete.gov.tr; Ministry application guide (2015, revised 2024): csgb.gov.tr (PDF)
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.