IEC 60079-10-1:2020

Overview

IEC 60079-10-1:2020 - Explosive atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres - defines the methodology for classifying three‑dimensional areas where flammable gas or vapour mixed with air may create ignition hazards. Edition 3.0 (2020) provides guidance to support the safe design, construction, operation and maintenance of equipment for use in hazardous areas. The standard clarifies scope and exclusions (for example, mines susceptible to firedamp, manufacture of explosives, domestic premises, medical rooms and certain flammable mists or dusty atmospheres) and introduces the concept of a zone of negligible extent.

Key topics and technical requirements

• Hazardous area classification methodology: structured approaches including classification by sources of release, simplified methods and combinations of methods.
• Sources and forms of release: identification and assessment of continuous, primary and secondary releases; gaseous releases; liquefied releases (by pressure or refrigeration); vapours and liquid pools.
• Ventilation and dilution: evaluation of natural and artificial ventilation, degree of dilution, ventilation effectiveness and criteria for availability of ventilation.
• Type and extent of zones: determination of Zone 0/1/2 (gas) areas based on release grade, dilution and ventilation; guidance on estimating spatial extent of hazardous zones.
• Risk and explosion assessment principles: explosion risk assessment, exclusion of catastrophic failures beyond normality, and consideration of other ignition sources (e.g., hot work, naked flames).
• Documentation and drawings: recommended presentation of hazardous areas, data sheets, and required records to support design, inspection and maintenance.
• Informative annexes: worked examples, equations for dilution/time estimates, guidance for flammable mists, hydrogen and hybrid mixtures, and references to industry codes.

Applications and who uses it

IEC 60079-10-1 is used by:

• Process, chemical and petroleum engineers for plant layout and piping design
• Electrical and instrumentation engineers for specifying explosion-protected equipment
• Safety, EHS and risk assessors conducting hazardous area classification and permit-to-work programs
• Maintenance planners and inspection bodies for safe operation and zoning documentation
• Certification and compliance teams demonstrating conformity with the IEC 60079 series

Practical uses include selecting appropriate explosion-protection techniques, defining safe distances, designing ventilation systems, preparing hot work permits and producing hazardous area drawings for procurement and inspection.

Related standards

• Other parts of the IEC 60079 series (equipment protection, selection and installation) are complementary for full explosive atmosphere management and compliance.
• Users should also consult relevant national regulations and industry codes referenced in IEC 60079-10-1 for site‑specific requirements.

Keywords: IEC 60079-10-1:2020, hazardous area classification, explosive gas atmospheres, flammable gas, vapour, ventilation, zone extent, hazardous zones, explosion protection.