ISO IEC 80079-20-2-2016 PDF

Full title and description

ISO/IEC 80079-20-2:2016 — Explosive atmospheres — Part 20-2: Material characteristics — Combustible dusts test methods. This dual-logo international standard specifies laboratory test methods for identification and characterisation of combustible dusts and dust layers so that areas where such materials exist can be classified and suitable electrical and mechanical equipment selected and installed to minimise ignition and explosion hazards.

Abstract

ISO/IEC 80079-20-2:2016 defines procedures for testing combustible dusts (clouds and layers) and provides standard atmospheric conditions for tests (temperature −20 °C to 60 °C; pressure 80–110 kPa; air with normal oxygen content ≈21 % v/v). It excludes recognised explosives, propellants and pyrophoric substances. This first edition consolidates and replaces the earlier IEC 61241 test-method parts and has an associated technical corrigendum issued in 2017.

General information

• Status: Published (International Standard; active edition).
• Publication date: February 2016 (ISO metadata: 2016-02; IEC publication records show February 2016; ISO national approvals list 25 February 2016).
• Publisher: International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC) — dual-logo publication.
• ICS / categories: 29.260.20 (Electrical apparatus for explosive atmospheres); also referenced under explosion protection/related ICS classes.
• Edition / version: Edition 1 (2016).
• Number of pages: metadata varies by distributor — ISO lists 82 pages; IEC webstore package references an edition with combined contents (including corrigenda) listing up to ~95 pages; corrigendum is 10 pages.

Scope

The standard specifies laboratory test methods for the identification and characterisation of combustible dusts and dust layers to support area classification and safe selection/installation of equipment in environments where combustible dust may be present. It gives required test atmospheres and limits, and it excludes materials that do not require atmospheric oxygen for combustion (explosives and propellants) and pyrophoric substances. The document consolidates earlier IEC 61241 test-method parts into a single technical revision.

Key topics and requirements

• Standard test atmospheres and conditioning requirements for sample preparation (temperature, pressure, oxygen content).
• Methods for characterising dust cloud ignitability and explosibility (parameters and test procedures used to determine MEC, MIT for clouds, MIE and related measures as applicable).
• Methods for dust layer testing (layer ignition/auto‑ignition tests and hot-surface ignition assessments).
• Electrical/resistivity measurement methods for dust layers and considerations for electrostatic ignition risks.
• Reporting requirements, test data presentation and limitations/exclusions of the test methods.
• Relationship to legacy IEC 61241 parts: the standard replaces IEC 61241-2-1, IEC 61241-2-2 and IEC 61241-2-3 and integrates their test methods into a single document.

Typical use and users

Used by independent testing laboratories, product and equipment manufacturers, safety and process engineers, certifying bodies and competent authorities to characterise dust hazards, support dust‑hazard analyses, determine suitability of equipment for areas with combustible dust, and to guide design of protection measures (venting, suppression, grounding/earthing, housekeeping and layout). The standard is a reference for technical dossiers, conformity assessment and equipment selection.

Related standards

ISO/IEC 80079-20-2 is part of the ISO/IEC 80079 series on explosive atmospheres. Closely related documents include ISO/IEC 80079-20-1 (material characteristics — gases and vapours — test methods and data), ISO/IEC 80079-34 (quality systems for manufacture of Ex equipment), ISO 80079-36 and ISO 80079-37 (non-electrical equipment methods and protection types), and the broader IEC/ISO 60079 / 80079 family (general requirements, equipment design and installation guidance). Earlier IEC 61241 parts that were replaced are relevant for historical reference.

Keywords

combustible dust; dust test methods; explosive atmospheres; minimum ignition energy (MIE); minimum explosible concentration (MEC); minimum ignition temperature (MIT); dust layer ignition; electrical resistivity; Kst / deflagration index; material characteristics; ISO/IEC 80079 series.

FAQ

Q: What is this standard?

A: ISO/IEC 80079-20-2:2016 is an international test-method standard that specifies laboratory procedures to identify and characterise combustible dusts and dust layers so that hazardous areas can be classified and suitable equipment and protective measures selected.

Q: What does it cover?

A: It covers test atmospheres and methods for assessing dust cloud and dust layer ignitability/explosibility, electrical/resistivity measurements for layers, reporting of test results, and exclusions (e.g., explosives, propellants, pyrophoric materials). It consolidates several older IEC 61241 test-method parts into one document.

Q: Who typically uses it?

A: Independent testing laboratories, equipment manufacturers, safety/process engineers, conformity assessment bodies, notified bodies and regulators who need validated test methods and data to support hazard assessments, equipment selection, certification and safe plant design.

Q: Is it current or superseded?

A: The document was published in February 2016 and a technical corrigendum was issued in March 2017. ISO records show the standard was reviewed/confirmed in 2021 and remains the current edition pending normal review/revision cycles (ISO lifecycle stage indicates it is to be revised at the next systematic review). Users should check national adoption or replacement notices for the most current status before relying on harmonized/regulatory references.

Q: Is it part of a series?

A: Yes — it is part of the ISO/IEC 80079 family addressing explosive atmospheres (material characteristics, equipment requirements, quality systems and methods). Notable companion parts include ISO/IEC 80079-20-1 (gases/vapours test methods), ISO/IEC 80079-34 (quality systems) and ISO 80079-36/37 (non-electrical equipment).

Q: What are the key keywords?

A: Combustible dust; dust test methods; explosive atmospheres; MIE; MEC; MIT; layer ignition; electrical resistivity; Kst; material characteristics; ISO/IEC 80079.