Hazardous Area Classification and Zone Determination

Program Overview

Area classification is the foundation of every explosion protection decision. If a zone is drawn too small, ignition sources end up in flammable atmospheres; if it is drawn too large, cost and complexity escalate without improving safety. This program teaches engineers to classify areas methodically, defensibly and in line with IEC 60079-10-1 and its AS/NZS adoption.

Participants study combustion fundamentals and the properties of flammable gases, vapors and combustible dusts, then apply the classification procedure: identifying sources and grades of release, assessing ventilation degree and availability, and determining zone type and extent. Results are captured in classification schedules and drawings and linked to equipment selection, installation and the verification dossier. The legal framework, including DSEAR, is covered for organizations with UK-regulated assets.

Learning Outcomes

• Explain combustion concepts, flammable limits, flash point and autoignition temperature
• Characterize gases, vapors and dusts by group, temperature class and other relevant properties
• Identify sources and grades of release and assess ventilation effectiveness
• Determine hazardous zone type and extent using IEC 60079-10-1 methods
• Prepare area classification drawings, schedules and supporting data
• Link classification results to equipment selection and verification dossier requirements

Program Modules

1. Legal Requirements, Codes and Recommended Practices — regulatory duties, DSEAR principles and the IEC 60079-10 framework
2. Basic Combustion Concepts and Terminology — fire triangle, LFL and UFL, flash point and ignition energy
3. Properties of Explosive Gases, Vapors and Combustible Dusts — density, volatility, group and T-class, dust layers and clouds
4. Classification Procedure and Data Analysis — gathering process data, release sources and grades of release
5. Determination of Zone Extent — release rate, ventilation degree and availability and dilution assessment
6. Documentation of Hazardous Area Zones — drawings, schedules and classification reports
7. Equipment Selection and Installation Requirements — EPLs, gas groups and temperature classes matched to zones
8. Electrical and Explosion Protection Techniques — overview of protection concepts used within each zone
9. Record Keeping and the Verification Dossier — maintaining classification evidence throughout the asset lifecycle

Who Should Attend

• Process safety and loss prevention engineers
• Electrical and instrument design engineers
• HSE managers in oil, gas, chemical and pharmaceutical facilities
• Ex inspectors and verification engineers
• Facility engineers responsible for plant modifications

Standards & Codes Referenced

• AS/NZS IEC 60079.10.1:2022 (Classification of areas, explosive gas atmospheres)
• AS/NZS IEC 60079.10.1:2022 Supplement 1:2022
• IEC 60079-10-1 (Classification of areas, explosive gas atmospheres)
• IEC 60079-10-2 (Classification of areas, explosive dust atmospheres)
• DSEAR 2002 (UK Dangerous Substances and Explosive Atmospheres Regulations)

Assessment & Certification

Competence is confirmed through a written examination on classification principles, zone determination and documentation and a practical assessment in which participants classify a process area case study and prepare its zone drawing and schedule. Practical sessions take place at ASEEE-approved training centers under the supervision of a qualified assessor.

Successful candidates receive the ASEEE competency certificate, which carries a unique ID that employers and clients can verify online through Certificate Check. Recertification is recommended every 5 years or whenever governing editions change significantly.