IICRC S520 is the industry standard most mould remediators in Australia refer to: the ANSI/IICRC S520 Standard for Professional Mold Remediation, published by the US-headquartered IICRC and now in its fourth edition (2024). It is a voluntary procedural standard, not an Australian law or licence. Australian guidance on mould comes from health and safety authorities, and the regulated parts of a mould job (plumbing, electrical, asbestos, work at heights) are covered by their own licences and safety rules.
Its value to you is a shared reference for what a properly run job looks like, so you can compare quotes on substance.
What S520 actually is
S520 is published by the Institute of Inspection, Cleaning and Restoration Certification (IICRC) and carries accreditation from the American National Standards Institute, which is what the “ANSI/” prefix means. The IICRC describes it as “a procedural standard for the remediation of mold damaged structures and contents” in residential, commercial and institutional buildings. Its sections cover the principles of mould remediation, inspection, structural, contents and HVAC remediation, and post-remediation verification, and it treats cleaners, antimicrobial chemicals and coatings as remediation tools rather than the remediation itself.
In practice the standard comes down to five principles:
- Investigate before treating. Find and correct the moisture source; mould without a fixed source comes back.
- Contain the work. Isolate the work area so disturbed spores do not spread to clean parts of the building, with negative air pressure on larger jobs.
- Remove what cannot be reliably cleaned. Porous materials that mould has grown into are generally removed, not sprayed and left.
- Control the air and the moisture. HEPA filtration during work and drying to a target before closing up.
- Verify before sign-off. Check the result against agreed criteria. See post-remediation verification explained.
The IICRC sells the full standard; it is not free to read. You do not need a copy to use it well. You need a quote that describes how each principle will be applied to your job.
What Australian guidance exists
There is no Australian equivalent of S520 for mould remediation, but there is official guidance on mould itself:
- NSW Health’s mould fact sheet covers health effects, who is more at risk, and household cleaning. It notes that absorbent materials such as carpet may need to be professionally cleaned or replaced if contaminated, and suggests an occupational hygienist offering specialist mould testing where hidden contamination is suspected.
- enHealth’s guidance on the potential health effects of mould, from the national Environmental Health Standing Committee (published December 2021), consolidates health advice following the parliamentary inquiry into biotoxin-related illnesses.
- Work health and safety law applies to the people doing the work, which is where the SWMS section below comes in.
We do not cite an Australian Standard (AS or AS/NZS) for mould remediation because we have not been able to verify one that covers it. Be cautious of quotes that name one without saying which clause applies.
Is mould remediation a licensed trade in NSW?
Not as a category of its own. The NSW Government’s list of building and trade licence categories includes plumbing, electrical, waterproofing, dry plastering and roof plumbing, among others, but no mould remediation category. What that means for you:
- The remediation itself is usually done by an unlicensed but (ideally) trained specialist, which is why the process standard and the written scope carry so much weight.
- The regulated work around it must be done by the right licence holder: a plumber for the leak, an electrician for the exhaust fan wiring, a waterproofer for a failed shower membrane. You can check a licence on the NSW Government licence check.
- Asbestos is separate and strictly regulated. Asbestos must be removed by a licensed asbestos removalist; friable asbestos needs a Class A licence. SafeWork NSW’s asbestos guidance recommends using a licensed asbestos professional to remove any amount of non-friable asbestos. If mouldy sheeting in an older home could contain asbestos, it must be assessed before anyone cuts it.
IICRC, NORMI and ACAC credentials
Because there is no licence, you will see training credentials instead. None of them is an Australian government licence.
| Credential body | What it is | What to ask |
|---|---|---|
| IICRC | US-headquartered body that publishes S520 and certifies technicians. Its Applied Microbial Remediation Technician (AMRT) course covers mould and sewage remediation and requires the Water Restoration Technician (WRT) credential first. | Which technician on my job holds AMRT? Can I check them on the IICRC Global Locator? |
| NORMI | The National Organization of Remediators and Microbial Inspectors, a US certifying body with trained members in Australia. | What did the course cover, and when? |
| ACAC | The American Council for Accredited Certification, a US body focused on indoor environmental assessment credentials. | Is this person doing assessment, remediation, or both? |
A credential shows that a person completed training and passed an assessment at some point. It does not show that the standard is followed on your job, that equipment is maintained, or that the scope suits your house. A certified contractor who cannot explain their containment plan, or who will not put the scope in writing, should still make you cautious.
S520 versus a SWMS
These are different documents that quotes often blur. S520 describes how remediation should be done. A safe work method statement (SWMS) is a work health and safety document. Safe Work Australia’s SWMS information sheet says a SWMS sets out the high risk construction work activities to be carried out, the hazards arising from them and the controls to be used, and that it must be prepared before that work starts.
Mould remediation is not itself on the high risk construction work list, but tasks on a mould job often are. The listed activities include:
| Task on a mould job | Listed high risk construction work |
|---|---|
| Entering a subfloor or roof void | Work in or near a confined space |
| Roof or upper-storey access to fix the moisture source | Risk of a person falling more than 2 metres |
| Cutting or removing sheeting in an older home | Work likely to involve disturbing asbestos |
| Strip-out that touches load-bearing elements | Demolition of load-bearing structure |
| Work around exhaust fan or downlight wiring | Work on or near energised electrical installations |
For a wipe-down of a bathroom ceiling, a SWMS is paperwork nobody needs. For subfloors, roofs or older sheeting, it is the point. Commercial sites and strata common property usually require a SWMS and insurance certificates before granting access.
What to look for in a quote or report
Measure any quote against the five principles. A quote that follows S520 should:
- Name the moisture source and say who is fixing it.
- Describe containment suited to the size of the job.
- List what will be removed and what will be cleaned, and why.
- Include air filtration and drying, with a moisture target.
- Explain how the job will be verified, and whether that check is independent.
- Attach the right paperwork: insurance, licence details for any regulated trade work, a SWMS where high risk work is involved, and a written completion record with readings.
If a quote cannot answer most of these for anything bigger than a small surface patch, it is probably pricing a cleaning job. A standards-aligned job costs more for real reasons (equipment, containment, disposal, time), which our mould removal cost guide explains, and our guide to choosing the right service has the full question list.
How this site uses the standard
Illawarra Mould Removal is a referral service and does not perform remediation or hold an IICRC certificate. Enquiries are passed to an independent local remediation professional who quotes in their own name; their identity and any licence details are provided before you accept a quote, and you are entitled to ask them every question above. See our mould remediation service for how a job is scoped, or start on the contact page.
Frequently asked questions
What is IICRC S520?
It is the ANSI/IICRC S520 Standard for Professional Mold Remediation, a procedural standard published by the IICRC, currently in its fourth edition (2024). It covers how remediation should be planned and carried out, from inspection and containment to post-remediation verification.
Is IICRC S520 a legal requirement in Australia?
No. It is a voluntary industry standard. Australian law instead regulates the work around a mould job, such as plumbing, electrical and asbestos removal, and work health and safety.
Does a mould remediator need to be IICRC certified?
Not by law. The IICRC’s AMRT certification shows structured mould remediation training, and you can check it on the IICRC Global Locator, but a contractor’s written scope and method tell you more about your job than the certificate does.
Do I need a SWMS for mould remediation?
A SWMS is required before high risk construction work, such as work in a confined space, work with a risk of falling more than 2 metres, or work likely to disturb asbestos, according to Safe Work Australia. A subfloor or roof void mould job often involves one of these; a simple bathroom clean does not.
Does following S520 guarantee mould will not come back?
No. It removes the growth correctly and deals with the moisture source in the scope, but new leaks or poor ventilation later can still cause new growth.