Product Overview

Summary: This Hazardous Area Classification Safe Operating Procedure provides a clear, defensible method for identifying, classifying and documenting hazardous areas where flammable gases, vapours, mists or combustible dusts may be present. It helps Australian businesses establish compliant zoning, select suitable equipment and implement controls that minimise ignition risks and support ongoing WHS and electrical safety obligations.

Hazardous area classification is a critical foundation for controlling explosion and fire risks in facilities where flammable gases, vapours or combustible dusts may be present, such as fuel depots, wastewater treatment plants, grain handling facilities, chemical plants and manufacturing sites. This Safe Operating Procedure sets out a structured, repeatable process for identifying potential sources of release, determining zone types and extents, documenting classifications and ensuring that plant, equipment and electrical installations are appropriately specified for the designated zones.

By implementing this SOP, businesses can move away from ad‑hoc or undocumented decisions and towards a robust, evidence‑based approach that stands up to regulator and insurer scrutiny. The procedure supports compliance with Australian WHS legislation and key electrical and hazardous area standards, reduces the likelihood of ignition in explosive atmospheres and provides a clear reference for designers, contractors and maintenance teams. It also helps organisations manage change over time, ensuring that new equipment, process modifications and layout changes are assessed consistently and that hazardous area drawings and registers remain current and accurate.

Key Benefits

• Ensure hazardous area zoning is consistent with Australian Standards and WHS legislation.
• Reduce the risk of explosion and fire by systematically identifying and controlling ignition sources.
• Standardise how hazardous areas are assessed, documented and reviewed across all sites and projects.
• Support correct selection, installation and maintenance of Ex-rated electrical and mechanical equipment.
• Demonstrate due diligence to regulators, insurers and clients through clear records and traceable decisions.

Who is this for?

• WHS Managers
• Electrical Engineers
• Electrical Supervisors
• Instrumentation and Control Engineers
• Maintenance Managers
• Operations Managers
• Site Supervisors
• Project Engineers
• Process Safety Engineers
• Risk and Compliance Managers

Hazards Addressed

• Explosion from ignition of flammable gas or vapour atmospheres
• Dust explosions in areas with combustible dust accumulation
• Fire resulting from ignition of flammable liquids or mists
• Ignition from non-rated electrical or mechanical equipment in hazardous zones
• Electrostatic discharge in areas with flammable atmospheres
• Hot surface ignition from process equipment and machinery
• Inadequate ventilation leading to accumulation of explosive atmospheres
• Uncontrolled changes to plant or process affecting hazardous area boundaries

Included Sections

• 1.0 Purpose and Scope
• 2.0 Definitions and Key Concepts (Zones, Gas Groups, Temperature Classes)
• 3.0 Roles, Responsibilities and Competency Requirements
• 4.0 Applicable Legislation, Standards and Codes of Practice
• 5.0 Pre‑Assessment Preparation and Information Gathering
• 6.0 Identification of Hazardous Substances and Sources of Release
• 7.0 Determining Zone Types and Extents (Gases, Vapours and Dusts)
• 8.0 Ventilation, Dilution and Environmental Considerations
• 9.0 Development and Maintenance of Hazardous Area Drawings and Registers
• 10.0 Equipment Selection, Marking and Suitability for Classified Areas
• 11.0 Integration with Design, Procurement and Installation Processes
• 12.0 Change Management and Periodic Review of Classifications
• 13.0 Documentation, Recordkeeping and Version Control
• 14.0 Training, Communication and Contractor Management
• 15.0 Audit, Verification and Continuous Improvement
• 16.0 References and Supporting Tools (Checklists, Templates, Example Calculations)

Legislation & References

• Work Health and Safety Act 2011 (Cth and harmonised state/territory variants)
• Work Health and Safety Regulations 2011 (hazardous chemicals and electrical safety provisions)
• Safe Work Australia – Model Code of Practice: Managing risks of hazardous chemicals in the workplace
• Safe Work Australia – Model Code of Practice: Managing electrical risks in the workplace
• AS/NZS 60079.10.1: Explosive atmospheres – Classification of areas – Explosive gas atmospheres
• AS/NZS 60079.10.2: Explosive atmospheres – Classification of areas – Explosive dust atmospheres
• AS/NZS 60079.14: Explosive atmospheres – Electrical installations design, selection and erection
• AS/NZS 3000: Electrical installations (Wiring Rules)
• AS/NZS ISO 31000: Risk management – Guidelines