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Hazardous area classification

The EI’s Area Classification Working Group (ACWG) is responsible for the development of technical content contained in Model code of safe practice Part 15: Area classification code for installations handling flammable fluids (EI 15, formerly referred to as IP 15). EI 15 is a well-established, internationally accepted publication that provides methodologies for hazardous area classification around equipment storing or handling flammable fluids in the production, processing, distribution and retail sectors. It constitutes a sector-specific approach to achieving the hazardous area classification requirements for flammable fluids required in the UK by the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002 and in doing so, provides much more detail than BS EN 60079-10 Electrical apparatus for explosive gas atmospheres: Classification of hazardous areas. Note that the scope of EI 15 excludes hazardous area classification arising from dusts.

EI 15
The current edition of EI 15 presents the following three complementary approaches for hazardous area classification:

  • The direct example approach, which is limited to common facilities
  • The point source approach, where release rates are dependent on process conditions; and
  • The risk-based approach.

The point source approach can be used for all situations; the risk-based approach is an optional methodology for secondary grade releases which may reduce the extent of the hazardous area determined by the point source approach.

The 3rd edition of EI 15 was published in July 2005. It provides, primarily, both technical and editorial clarification on issues that have been raised by users of the 2nd edition (published in 2002). In addition, further technical and editorial changes have been made. To assist those who are considering purchasing a copy or for users who want more information, list of Key technical changes are available to view free of charge.

The 4th edition of EI15 will be published in July 2015. It includes extensive technical changes from the 3rd edition, click here.

Handling flammable liquids: Using the updated edition of EI15 area classification code
was held on the 16 July 2015, Manchester UK

This seminar launched the fourth edition of the Model code of safe practice part 15: Area classification code for installations handling flammable fluids. Presentations were given from the contributors of the guidance on key technical changes of the fourth edition including: Ventilation, Mists, Frequency Data, and Consequence Modelling.

For more information, and to register for this seminar, click here.

Technical queries
Users of EI 15 and its supporting publications, seeking a consultant to provide technical support with carrying out hazardous area classifications, should use the Consultant Database maintained by the EI Library and Information Service.

To seek clarification of technical issues in EI 15, contact the EI Library and Information Service. Note, however, that this is not a consultancy service and as it draws upon volunteers from the ACWG, it may take some time to respond to issues raised.

To facilitate the continuing technical development of EI 15, your technical feedback would be welcome.

Participation in the Working Group
The ACWG would welcome the participation of additional upstream petroleum industry practitioners so as to ensure their continuing applicability of the resources to upstream operations.

For further information on the ACWG, please contact Toni Needham 
e:, t: +44 (0)20 7467 7160.

Click here for further information on relevant Technical Publications.

Two papers presented at IChemE’s Hazards XIX Process safety and environmental protection: What do we know? Where are we going? referred extensively to the EI 15 methodology. The papers Experiences and issues in ATEX and DSEAR compliance and Area classification methodology for hydrogen-cooled alternators in power stations are included in the symposium proceedings, which are available from IChemE (Symposium proceedings No. 151, ISBN 13 978 0 85295 492 8).