ISO/IEC 80079-41 ED1

Explosive atmospheres – Part 41: Reciprocating internal combustion engines

Scope

ISO/IEC 80079-41:2026 specifies the technical requirements for design, construction, conversion, testing, marking, and the information required for use to avoid or minimise the possibility of ignition which could result from a reciprocating internal combustion engine intended for use in explosive atmospheres including:
- Group I EPL Mb for use in mines susceptible to firedamp,
- Group II EPL Gb and EPL Gc for use in explosive gas atmospheres, and
- Group III EPL Db and EPL Dc for use in explosive dust atmospheres.
For EPL Gc and Dc engines, only normal operating conditions are to be considered. There is no need to consider malfunctions (see B.2.1).
This document includes those tests of the engine and its ancillary devices that are required to verify compliance with this document.
This document applies to reciprocating internal combustion engines with compression ignition for EPL Mb, Gb, Gc, Db, Dc and gaseous fuelled, spark ignition, engines for EPL Gc. (see Annex G.)
This document does not define requirements relating to the driven machinery and equipment.
This document does not apply to
- explosive mixtures of vapours and gases, which tend to self-decompose (for example carbon disulphide (CS2), ethylene oxide (C2H4O), acetylene (C2H2) or which are chemically unstable;
- hydrogen fuelled engines;
- engines used in areas for the processing, manufacture or storage of explosives;
- gasoline and other spark ignited engines where the fuel is injected into the combustion chamber as a liquid; or
- electrical ignition spark systems.
This document solely deals with explosion protection requirements. Requirements on gaseous or particulate exhaust emissions are not covered by this document.
General safety requirements are not included in this document.
This document does not specify requirements for safety, other than those directly related to the possibility of ignition of flammable mixtures in the surrounding atmosphere, which can lead to an explosion.
This document supplements and modifies the general requirements of IEC 60079‑0 and ISO 80079‑36. Where a requirement of this document conflicts with a requirement of IEC 60079‑0 and ISO 80079‑36 as is applicable for Ex engines, the requirement of this document takes precedence.
The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which the engine can be operated are:
- temperature –20 C to +60 C
- pressure 80kPa (0,8bar) to 110kPa (1,1bar); and
- air with normal oxygen content, typically a volume fraction of 21%.
Additional consideration and additional testing are necessary for Ex engines operating outside the standard atmospheric conditions. The ignition hazard assessment, ignition protection provided, additional testing (if necessary), manufacturer’s technical documentation and instructions to the user are intended to clearly demonstrate the engine’s suitability for the conditions.