AS 4587:2020, Water mist fire protection systems — System design, installation and commissioning, is the Australian Standard for water mist (Standards Australia). It sets minimum requirements for designing, installing and commissioning water mist systems, and it is direct about something buyers often assume otherwise: a system installed to AS 4587 is not a deemed-to-satisfy alternative to a mandatory sprinkler system.
What does AS 4587 cover?
Standards Australia committee FP-011, Special Hazard Fire Protection Systems, prepared the second edition, published on 18 December 2020 to replace the 1999 first edition. The committee's members include the Australasian Fire and Emergency Service Authorities Council, CSIRO, Engineers Australia and Fire Protection Association Australia, and Standards Australia describes the main change as alignment with international and Australian standards.
The standard covers systems with closed or open nozzles, including systems that use compressed air or inert gas to produce the mist. A system may be arranged for total flooding, zoned total flooding, an assumed area of operation or local application, and designed to control, suppress or extinguish fires in specific industrial and commercial hazards. Its clauses run from uses and limitations and safety requirements, through components and installation, protected enclosures, detection and actuation, system design and hydraulic calculations, to commissioning and acceptance testing (AS 4587:2020 preview).
What does AS 4587 leave out?
- Residential occupancies and explosion suppression. Both are outside its scope.
- Maintenance. That sits in the AS 1851 series, not in AS 4587.
- Sprinkler replacement. It provides no requirements or guidance for water mist systems to replace mandatory sprinkler systems.
Why does AS 4587 give no design density?
Water mist performance depends heavily on the characteristics of the droplets and on how they are generated and distributed, so AS 4587 does not set fire performance criteria on an application rate or density basis. It treats water mist as an application-specific solution: each application or occupancy has to be proven against standardised fire tests and component tests, shown in a report from the fire test laboratory.
The same logic runs through the US and European standards. NFPA 750 requires a system to be designed to a listing based on fire tests (NFPA 750 explained), and EN 14972 carries application-specific fire test protocols (EN 14972 explained). What a fire test report proves, and what a component certificate does not, is set out in system fire testing vs component certificates.
Which standards does AS 4587 call up?
Its normative references include AS 2118.1 for sprinkler systems, AS 1670.1 and AS 1670.5 for fire detection and special hazards systems, AS 2941 for pumpsets, AS 2304 for water storage tanks, AS 4041 for pressure piping and AS 1210 for pressure vessels. A submission should show where each applies.
Can water mist replace sprinklers in Australia?
Not by the deemed-to-satisfy route. Where the National Construction Code's Deemed-to-Satisfy Provisions call for sprinklers, Specification 17 names the systems that satisfy them: AS 2118 standards and, in listed cases, Specification 18 and FPA Australia's FPAA101 systems. NCC 2025 Volume One does not mention water mist at all (NCC 2025 Volume One). A project that wants water mist instead has to show compliance with the relevant Performance Requirements through a Performance Solution, as explained in water mist as an NCC Performance Solution.
Tunnels follow a different framework. The Australian tunnel fire safety standard lists the water mist standard among its referenced documents, alongside the deluge standard; see AS 4825 explained.
What should a water mist submission in Australia include?
- the application and occupancy, and the fire test report from the laboratory that proves performance for it;
- the component test evidence;
- the system arrangement (total flooding, zoned, assumed area of operation or local application) and its objective: control, suppression or extinguishment;
- hydraulic calculations, and the commissioning and acceptance test plan;
- the maintenance regime under the AS 1851 series.
Where the system stands in for required sprinklers, the same evidence has to carry the Performance Solution.
Where Mistelix stands
Mistelix designs its water mist systems with reference to NFPA 750. Full-scale fire testing, FM Approval and UL listing are planned. Our live status against every standard we work to is in our approvals ledger.
Sources: Standards Australia, AS 4587:2020 product page and preview, for the committee, preface, introduction, scope and normative references summarised above; ABCB, NCC 2025 Volume One, Specification 17.