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GIS 42: Hazardous Area Classification and Gas Installations covered by Gas Industry Codes

Background

Energy Safe Victoria (ESV) is aware of industry participants classifying some industrial and commercial gas installations within consumer premises as hazardous areas. This information sheet is published to inform industry about the gas installations covered by specific Gas Industry Codes (Standards), where domestic and commercial consumer piping and appliance installations are generally considered non-hazardous (classified as not creating a hazardous area).

Legislation

In Victoria, Gas Safety legislation[i] mandates that all gasfitting work (construction, installation, replacement, repair, alteration, maintenance, testing or commissioning) of a gas installation is to be carried out in accordance with AS/NZS 5601.1 (Gas installations, Part 1: General installations), AS/NZS 5601.2 (Part 2: LP Gas installations in caravans and boats for non-propulsive purposes), AS 4575 (Gas appliances — Servicing of Type A appliances); and other normative referenced technical standards including AS 3814 (Industrial and commercial gas fired appliances) and AS/NZS 1596 (The storage and handling of LP Gas).

Similarly, Electricity Safety legislation[ii] mandates that all electrical installation work (installation, alteration, maintenance and repairs) are to be carried out in accordance with AS/NZS 3000 (the Wiring Rules), and other normative technical standards it references including AS/NZS 60079.14 (Explosive atmospheres Design selection, erection and initial inspection).

This includes gasfitting and electrical installation work in a hazardous area, which is defined as an -

  • area in which an explosive atmosphere is present, or may be expected to be present, in quantities such as to require special precautions for the construction, installation and use of equipment.[iii]

A non-hazardous area (on account of explosive gas atmospheres) is defined as an -

  • area in which an explosive gas atmosphere is not expected to be present in quantities such as to require special precautions for the construction, installation and use of equipment.[iv]

Hazardous Area Classification

As is recognised within the Wiring Rules, the responsibility for classification of a hazardous area rests with the persons or parties in control of the installation (typically the owner or occupier of the premises), in accordance with the requirements contained in AS/NZS 60079.10.1 (Explosive atmospheres Classification of areas - Explosive gas atmospheres) for gas or vapour and AS/NZS 60079.10.2 (Explosive atmospheres Classification of areas - Explosive dust atmospheres) for combustible dusts[v].

AS/NZS 60079.10.1 and AS/NZS 60079.14 establish that -

  • Area classification is a method of analysing and classifying the environment where explosive gas atmospheres may occur, so as to facilitate the proper selection and installation of equipment to be used safely in that environment. The classification also takes into account the ignition characteristics of the gas or vapour such as ignition energy and ignition temperature[vi]
  • … the measures or conditions or control shall be documented by a competent person who -
    • (i) is familiar with the requirements for this, and any other relevant standards and codes of practice concerning the use of electrical equipment and systems for use in hazardous areas, and
    • (ii) has access to all information necessary to carry out the assessment.[vii]
  • A competent person is defined as an individual that can demonstrate appropriate technical knowledge and relevant skills to make the necessary assessments of the safety aspect under consideration[viii]

AS/NZS 60079.10.1 has a series of clauses to support a competent person, giving guidance on the procedure for classifying areas in which there may be an explosive gas atmosphere. This Standard contains detailed recommendations regarding the extent of the hazardous areas in specific industries or applications, where reference may be made to national or industry codes relating to those applications.

In that context, AS/NZS 60079.10.1 addresses use of industry codes and national standards[ix], including Fuel gas installations, which establishes that -

‘in most cases compliance to the relevant gas codes would result in a classification of non-hazardous or lead to a zone of negligible extent’;

and refers to Annex K for examples of relevant codes, where table K.1 identifies the Australia and New Zealand reference AS/NZS (IEC) 60079.10.1 with its application to include the national Supplement.

AS/NZS IEC 60079.10.1: 2022 Sup 1:2022 (the Supplement)

The Supplement establishes its objective ‘to provide commentary and additional information to support the application of AS/NZS IEC 60079.10.1: 2022[x]. The contents of Appendix E include classification examples for Flammable Gasses – Gas industry Codes (Standards) , and addresses Consumer Installations[xi].

This specifically addresses domestic and commercial consumer installations, to state –

Consumer installation are those systems that are located downstream of a supply point. The supply point may be immediately downstream of a consumer billing meter, an LPG or LNG supply (e.g., tank or cylinder first stage regulator), or a supply source in a privately owned and operated biogas installation.

Consumer installations are covered by AS/NZS 5601.1, which is administered by the relevant authority.

Domestic or commercial installations (e.g., hospitality, education and health or similar institutions) primarily providing gas for cooking or heating purposes are generally low pressure and not deemed to be a hazard.

The classification of these consumer piping and appliance installations are considered non-hazardous.

Annex ZA.6.2 of AS/NZS 60079.10.1 illustrates common industry situations relevant to consumer installations of gas appliances covered by the Gas Industry Codes (Standards) [PM5] AS/NZS 5601, AS 3814 and AS/NZS 1596, and highlights the following situations which are considered to create a hazardous area -

  • Within the exclusion zone of a cylinder pressure relief device and vent pipe discharge points
  • Within pits (entire pit if enclosure is not adequately ventilated)
  • For natural gas cylinders above 30m3 aggregate gas capacity
  • For natural gas cylinder filling compressors in an inadequately ventilated locations above 10m3/h rated capacities; and
  • Within 3m of the end of the filling hose for slow natural gas cylinder fill hoses at greater than 10m3/h rating, and all fast fill hoses.

In accordance with Annex ZA.6.2.2.6, ‘Other Areas’ are considered to be non-hazardous.

This is consistent with note 2 of the scope of annex ZA.6.2.1, which states -

The exemption for gas appliances and equipment covered by gas industry codes is based on the premise that these codes provide, by equipment design and instructions, an installation that produces a non-hazardous environment. In some instances, particularly for larger industrial equipment, the installer needs to ensure that this premise is justified.

NOTE: the application of the above relates to domestic or commercial gas installations within consumer premises, within the scope of AS/NZS 5601.1 which is limited to pressures up to 200kPa (low pressure). If the gas supply pressure exceeds 200kPa, an assessment should be carried out to ensure that the non-hazardous classification remains valid.

Further information

Contact ESV’s Technical Information Line via gastechnicalenquiry@energysafe.vic.gov.au, or by phone on 1800 652 563 (option 3).

Copyright AS/NZS 60079.14. Users must not copy or reuse this work without the permission of Standards Australia or the copyright owner.

References

[i] The Gas Safety Act 1997 and the Gas Safety (Gas Installation) Regulations 2018

[ii] The Electricity Safety Act 1998, and the Electricity Safety (General) Regulations 2019

[iii] Clause 1.4.15 of the Wiring Rules (AS/NZS 3000:2018)

[iv] Clause 3.2.2 of AS/NZS 60079.14 (2022)

[v] Clause 7.7.2.1 of the Wiring Rules (AS/NZS 3000:2018)
NOTE: The responsibility for classification of a hazardous area does not rest with a licensed electrician, or a gasfitter. Once an area in which an explosive atmosphere is to be present is classified via the preparation of an area classification and dossier (or otherwise determined by a competent person to be non-hazardous), an electrician should have the necessary information to select and install electrical equipment in, or related to the protection of electrical equipment in a hazardous area in accordance with the Wiring Rules and AS/NZS 60079.14, and a Licensed Electrical Inspector (LEI) to inspect the prescribed electrical installation work that is subsequently certified.

[vi] Clause 4.2 of AS/NZS 60079.10.1 (2022)

[vii] Clause 4.1 of AS/NZS 60079.14 (2022)

[viii] Clause 3.1.1 of AS/NZS 60079.14 (2022)

[ix] Clause 5.3 of AS/NZS 60079.10.1 (2022)

[x] Preface and introduction of AS/NZS IEC 60079.10.1 : 2022 Sup 1:2022 (the Supplement)

[xi] Appendix E.1.2 of the Supplement

Date: 04/02/2023 20:08

Controlled document

The currency and accuracy of this document cannot be guaranteed once printed or saved to a storage device. If in doubt, please check the ESV website for the current version.

Reviewed 29 January 2023

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