How are explosive atmospheres and Ex equipment regulated in Australia?

Through three layers. The model Work Health and Safety (WHS) Regulations require every person conducting a business or undertaking (PCBU) to manage the risks of hazardous atmospheres and ignition sources. State electrical safety and mining laws add specific rules for Ex installations and equipment. In practice, classification, selection, installation and inspection follow the AS/NZS 60079 series, with equipment certified under the IECEx or the Australian and New Zealand ANZEx scheme.

Short answer

• WHS Regulations 51 and 52: a hazardous atmosphere (regulation 51(2)) exists where flammable gas, vapour, mist or fumes exceed 5% of the lower explosive limit (LEL), combustible dust may form a hazardous area, oxygen is unsafe or oxygen enrichment raises fire risk; risks and ignition sources must be managed under the risk management rules.
• No national product directive comparable to the EU ATEX Directive 2014/34/EU. Equipment is normally supplied with a certificate of conformity under IECEx or ANZEx.
• Standards: AS/NZS 60079 parts (the Australian/New Zealand adoption of IEC 60079) for area classification, equipment selection and installation, and inspection.
• State electrical laws: for example in Queensland, an accredited auditor must inspect hazardous-area electrical installations affected by electrical work before they are first connected or reconnected to supply (Electrical Safety Regulation 2013, section 221).
• Underground coal mines: separate, stricter mining rules (for example NSW Work Health and Safety (Mines and Petroleum Sites) Regulation 2022, section 81).

What the WHS Regulations require

Regulation 51 of the Commonwealth WHS Regulations 2011 requires the PCBU to manage risks associated with a hazardous atmosphere in accordance with Part 3.1: identify, eliminate or minimise, apply the hierarchy of controls, maintain and review. Regulation 52 adds the same duty for ignition sources in a hazardous atmosphere, except where the ignition source is part of a deliberate process. Regulation 53 requires flammable and combustible substances, including gas cylinders, to be kept at the lowest practicable quantity. Confined spaces have their own rules in Part 4.3.

Equipment, installation and inspection in practice

There is no Australian equivalent of CE marking for Ex equipment. Purchasers and regulators expect equipment for classified zones to carry an Ex certificate of conformity, usually issued under the international IECEx scheme or the ANZEx scheme, and to be selected and installed according to AS/NZS 60079.14. Workplace Health and Safety Queensland states that equipment in a hazardous area must be suitably rated and effectively earthed and that the selection and installation requirements of AS/NZS 60079.14 are mandated; its inspectors can issue notices prohibiting the use of electrical equipment in hazardous areas until controls are verified. Electrical work itself is licensed under each state's electrical safety law.

Area classification and the records behind it (usually a classification drawing and an equipment list) are the starting point. Workplace Health and Safety Queensland states that the person with management or control of an installation where an explosive atmosphere can occur has a duty to ensure the classification has been made. Periodic inspection and maintenance follow AS/NZS 60079.17.

Mines

In NSW underground coal mines, section 81 of the Work Health and Safety (Mines and Petroleum Sites) Regulation 2022 requires the mine operator to ensure that plant used in a hazardous zone is explosion-protected, with a valid certificate of conformity or listing in the regulator's Explosion Protected Electrical Apparatus Approvals List. Equipment covered only by an old Mines Department Approval (MDA), which must also have been made before 1 October 2015, may not be used in a hazardous zone after 1 September 2028. Overhaul of explosion-protected plant follows AS 2290.1:2021. Queensland coal mines have their own regulator and rules.

Common mistakes

• Assuming ATEX certification alone settles Australian acceptance. Check what the purchaser, the state electrical regulator or the mining regulator requires; an IECEx or ANZEx certificate is the usual expectation.
• Treating the 5% LEL trigger as an alarm set point.
• Connecting a new hazardous-area installation in Queensland before the accredited auditor's inspection.

Related on excodex

• Occupational safety and health in Australia: law, authorities and employer duties
• The IECEx scheme explained: CoC, ExTR, QAR and the online certificate database
• Which countries accept IECEx certificates directly?
• Ex installation basics under IEC 60079-14
• Inspection of Ex installations under IEC 60079-17

Standards and further reading

• Work Health and Safety Regulations 2011 (Cth), regulations 51 to 53: https://www.legislation.gov.au/F2011L02664/latest/text
• Workplace Health and Safety Queensland, hazardous area installations: https://www.worksafe.qld.gov.au/laws-and-compliance/compliance-and-enforcement/audits-and-inspections/electrical-safety-audits/hazardous-area-installations-audits
• NSW Resources Regulator, explosion-protected plant: https://www.resources.nsw.gov.au/resources-regulator/safety/health-and-safety-management/electrical-engineering/explosion-protected
• AS/NZS 60079.10.1 (gas area classification), AS/NZS 60079.14 (design, selection, erection and initial inspection), AS/NZS 60079.17 (inspection and maintenance)
• AS 2290.1:2021, electrical equipment for coal mines: introduction, inspection and maintenance, part 1 hazardous areas

This article is general occupational safety and health information prepared by the excodex editorial team. It does not replace the applicable legislation, standards, manufacturers' instructions or the assessment of a competent OSH professional or occupational physician.