AS/NZS 2430.3.1:2004

This Standard provides examples of area classification and is based on the internationally accepted concept which recognizes the different degrees of probability with which explosive (flammable) concentrations of flammable gas or vapour may arise in installations in terms of both the frequency of occurrence and the probable duration of existence on each occasion.

This Standard provides examples of area classification and is based on the internationally accepted concept which recognizes the different degrees of probability with which explosive (flammable) concentrations of flammable gas or vapour may arise in installations in terms of both the frequency of occurrence and the probable duration of existence on each occasion. The recommended classifications of this Standard are based on the assumption that plant and equipment are adequately maintained. The Standard is part of a series which recommends the classifications of several commonly occurring situations. NOTE: Appendix A provides methods of classification. This Standard details general matters which must be taken into account when using any other of the AS/NZS 2430.3 series of Standards for the purpose of conducting an area classification. This Standard covers risks due to both fire and explosion. The examples in this Standard may not apply to specific occupancies where— (a) the quantity of release is either very large or very small, in such cases dispersion calculations may be required; (b) the design of a particular plant does not comply with the appropriate Australian or New Zealand Standards; or (c) ventilation, use of inert gases, vapour barriers or other methods, are used to reduce the extent or degree of risk of a particular hazardous area. In all cases classification may be made using the fundamental principles detailed in AS/NZS 60079.10. In general, classifications in accordance with the following codes are acceptable, subject to any additional provisions or modifications as required by the authority: (i) UK IP (Institute of Petroleum), Model Code of Safe Practice for the Petroleum Industry, Part 15: Area Classification Code for Installations Handling Flammable Fluids. (ii) API (American Petroleum Institute) RP 505, Recommended Practice for ‘Classification of Locations for Electrical Installations at Petroleum Facilities classified as Class I, Zone , Zone 1 and Zone 2’. (iii) BS 5908, Code of practice for fire precautions in the chemical and allied industries. Attention is drawn to the fact that an area classified non-hazardous, in accordance with this Standard, may not necessarily be safe in all respects, e.g. toxic and chemical hazards. Unless otherwise specified, the classifications given throughout this Standard are based on the ventilation criteria given in Appendix B.

First published in Australia as part of AS 1076.2-1977.
AS 2430.1 first published 1981.
AS 1076.2-1977 and AS 2430.1-1981 revised, amalgamated and redesignated AS 2430.1-1982.
AS 2430.1-1982 revised and redesignated in part as AS 2430.3-1987.
Second edition 1991.
First published in New Zealand as part of NZS 6101P:1972.
Revised and redesignated in part as NZS 6101.3:1991.
AS 2430.3-1991 and NZS 6101.3:1991 revised, amalgamated and redesignated in part as AS/NZS 2430.3.1:1997.
Second edition 2004.