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Hazardous Area Classification

SANS 10108, IEC 60079, EI 15 and NCOP 2022 zone classification with ATEX / Ex equipment selection — protecting your facility from flammable atmosphere ignition.

Hazardous Area Classification

Every Zone Correctly Classified. Every Ignition Source Controlled.

Hazardous Area Classification (HAC) is the systematic process of defining areas where flammable gases, vapours or dusts may be present in sufficient concentration to present an ignition risk. Correct classification is the foundation for selecting appropriate electrical and non-electrical equipment, controlling ignition sources and designing safe facilities.

Nexis PS performs HAC studies for new greenfield facilities, existing brownfield plants requiring re-assessment, and for facilities subject to process or layout changes. All studies are conducted in accordance with South African and international standards recognised by the regulator.

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HAC Services

  • Gas / Vapour Zone Classification (Zone 0, 1, 2)
  • Dust Zone Classification (Zone 20, 21, 22)
  • Zone Extent Determination using Release Grades
  • ATEX / Ex Equipment Category Selection
  • Hazardous Area General Arrangement (GA) Drawings
  • Electrical Equipment Schedule Development
  • Ex Inspection & Maintenance Schedule
  • NCOP 2022 Compliance Assessment
  • DSEAR 2002 Assessment (UK facilities)
  • EI 15 Petroleum Industry Classification
Zone Classification Methodology

A Structured Source-Release-Ventilation Approach

IEC 60079-10-1 (gases) and IEC 60079-10-2 (dusts) establish a deterministic methodology based on grade of release and ventilation adequacy. Nexis PS applies this methodology rigorously to produce defensible, auditable zone extents.

Gas & Vapour Zones

  • Zone 0 — Explosive atmosphere present continuously or for long periods
  • Zone 1 — Explosive atmosphere likely during normal operation
  • Zone 2 — Explosive atmosphere not likely; if present, only brief duration
  • Release source inventory and primary release point mapping
  • Grade of release (continuous / primary / secondary) determination
  • Ventilation degree and availability assessment
  • Zone extent calculation per IEC 60079-10-1 Annex B

Combustible Dust Zones

  • Zone 20 — Explosive dust cloud present continuously or frequently
  • Zone 21 — Explosive dust cloud likely during normal operation
  • Zone 22 — Explosive dust cloud not likely; if so, only briefly
  • Dust cloud and layer formation assessment
  • Minimum Ignition Energy (MIE) and Minimum Explosible Concentration (MEC)
  • Housekeeping and dust suppression controls impact on zone
  • Zone extent per IEC 60079-10-2

Equipment Selection

  • EPL (Equipment Protection Level) assignment for each zone
  • ATEX Cat 1 / 2 / 3 and IECEx certification alignment
  • Protection concept (flameproof, intrinsic safety, purge/pressurisation)
  • Non-electrical equipment — ATEX Directive 2014/34/EU
  • Electrical equipment register with Ex certification check
Applicable Standards

South African & International Regulatory Framework

SANS 10108

The Classification of Hazardous Locations and the Selection of Apparatus for Use in Such Locations. The primary South African standard bridging IEC 60079 for local regulatory compliance.

IEC 60079 Series

Part 10-1 (gas/vapour area classification methodology), Part 10-2 (dust area classification methodology), and the equipment standards (Parts 0–38) covering all major protection concepts.

EI 15 (Energy Institute)

Area Classification Code for Petroleum Installations. Used for petroleum refining, fuel storage and distribution facilities, providing prescriptive zone extents for common petroleum equipment configurations.

NCOP 2022

The South African National Code of Practice for Hazardous Installations, providing regulatory requirements for classification documentation, competency and record-keeping for licensable facilities.

DSEAR 2002 (UK)

Dangerous Substances and Explosive Atmospheres Regulations 2002, applicable for Nexis PS clients operating UK facilities. Requires formal DSEAR risk assessment and document package.

Study Deliverables

A Complete, Auditable HAC Document Package

HAC Report

A formal study report documenting methodology, standards applied, release source inventory, zone determination for each source, zone extent rationale and classification summary.

GA Zone Drawings

Hazardous Area General Arrangement drawings showing plan and elevation views with zone extents, zone type labels and boundaries — suitable for inclusion in plant safety case documentation.

Equipment & Inspection Schedules

Electrical equipment register listing each item of Ex-certified equipment, its zone location, EPL, protection concept and certification reference. Accompanied by an initial Ex inspection schedule per IEC 60079-17.

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