As extreme weather events and persistent dampness continue to impact buildings across Australia, the conversation around mould has shifted from appearance to health. At this year’s ISSA Cleaning & Hygiene Expo in Sydney, two industry specialists led a workshop unpacking the science, regulation and business of mould remediation, helping operators navigate a field that demands both technical precision and professional accountability.
INCLEAN spoke with one of the presenters, Dr Gavin Macgregor-Skinner, about how the new AS-IICRC S520:2025 Standard is shaping local practice and why a standards-driven approach is key to building a sustainable remediation business.
INCLEAN: The new AS-IICRC S520:2025 Standard is a big moment for Australia’s mould remediation industry. From your perspective, how is it shifting the way operators approach their work, and what kind of changes do you expect to see on the ground?
Gavin Macgregor-Skinnner: The AS-IICRC S520:2025 Standard marks a significant step for Australian mould remediation, establishing a consistent procedural baseline that operators, insurers and regulators can align with. It formalises containment, documentation and verification practices, promoting greater operational discipline and quality assurance.
However, while it enhances procedural rigour, the S520 still primarily focuses on visible mould growth (Condition 3) and spore deposition. It doesn’t yet fully integrate decades of microbiological and toxicological research showing that occupant exposure often begins long before visible signs appear – through aerosolised biotoxins, endotoxins and microbial fragments that can persist beyond traditional remediation.
This is where the NORMI NCRSI Level 4 Protocol completes the picture. NCRSI extends beyond containment to whole-environment biotoxin decontamination, reflecting contemporary science and health considerations. On the ground, we expect to see a two-tiered evolution: S520 compliance becoming the industry standard for procedural consistency, while advanced practitioners increasingly adopt NCRSI principles to deliver scientifically comprehensive, health-focused remediation outcomes.
For nearly two decades, the IICRC S520 Standard for Professional Mould Remediation has provided the industry’s most widely accepted framework for addressing fungal contamination in buildings. Its emphasis on source removal, engineering controls, containment and worker safety established much-needed consistency in an area that once lacked formal guidance.
However, it is equally important to recognise the S520’s defined scope and disciplinary limits. By its own definition, the standard focuses primarily on Condition 3 environments, spaces where fungal growth and spore deposition are observable. The framework was designed to guide the removal and cleaning of visible contamination, not to address the complex microbial and biochemical dynamics that occur before visible growth appears.
Consequently, the S520 gives minimal attention to aerosolised biotoxins, mycotoxins, bacterial endotoxins, β-glucans and other microbial fragments that are now well documented in scientific and clinical research as contributing to building-related illness and inflammatory responses in occupants.
Over the past two decades, the scientific understanding of indoor microbial ecology has advanced substantially. Environmental medicine, toxicology and microbiology have established that health effects can arise from exposure to non-viable microbial particles and secondary byproducts that persist long after visible mould is removed. These findings necessitate a broader approach that bridges building science and human health science.
That evolution is represented in the NORMI NCRSI Certification and Level 4 Protocol, which builds upon the foundational principles established by the IICRC while extending them into a contemporary, health-centred framework. The NCRSI model incorporates the latest research in microbial and toxicological science to assess and mitigate not only visible fungal colonisation but also submicron biotoxin contamination.
It expands the concept of remediation beyond containment and material cleaning to encompass whole-environment biotoxin decontamination, including advanced air and surface purification, environmental sampling validation and occupant reintegration protocols. This alignment of contemporary science with practical field methods represents not a replacement of the IICRC framework but its natural progression into a more comprehensive, evidence-informed standard.
As the field continues to mature, collaboration between standards organisations, restoration professionals and health scientists will be essential. The IICRC S520 was groundbreaking in its time; the NORMI NCRSI Level 4 Protocol represents the next chapter, modernising mould remediation to address the realities of biotoxin exposure and to safeguard both buildings and the people who occupy them.
INCLEAN: Mould is a familiar problem in Australia, but professional remediation is still often misunderstood. What are some of the biggest myths or mistakes you come across when people try to manage water damage or mould themselves?
GMS: One of the most pervasive myths is that mould remediation is simply about cleaning visible mould and that once the black spots are gone, the problem is solved. In reality, mould spores, mycotoxins, β-glucans and bacterial endotoxins often become airborne long before visible growth, and these biotoxins can linger in dust, HVAC systems and building materials even after surface cleaning.
Another common mistake is underestimating moisture control and ignoring hidden contamination, which leads to recurring problems. DIY approaches often lack proper containment, use inadequate protective measures and fail to address the building science aspects that drive mould proliferation.
Effective remediation requires a scientifically informed, whole-environment approach, not just surface cleaning. This is why professional standards like the AS-IICRC S520 provide a foundation, but integrating contemporary research through protocols like NCRSI is essential for truly mitigating health risks.
A second major error is assuming that “killing” mould or wiping surfaces with biocides is sufficient. Dead or denatured organisms still release particulate fragments and secondary metabolites that remain biologically active. Effective remediation is about removal, containment and decontamination of the entire micro-environment. Without source removal, HEPA-level engineering controls, and post-remediation verification, contamination often rebounds.
Another myth is that moisture correction alone resolves the issue. While drying and structural repair are critical, they don’t address existing reservoirs of biotoxins or fine particulate contamination. Without targeted cleaning of HVAC systems, soft contents, and settled dust, occupants can continue to experience exposure long after water damage appears “repaired.”
Finally, there is a knowledge gap between traditional building-restoration protocols and the expanding body of microbiological and toxicological research. Contemporary frameworks, such as the NORMI NCRSI Level 4 protocol, bridge that gap by integrating environmental health science into building science.
INCLEAN: Your workshop touched on training, mentorship and operational excellence. In your view, what separates a high-performing remediation business, one that really gets it right, from those that fall short of compliance or quality?
GMS: High-performing remediation businesses are distinguished by their integration of science, process and culture. They go beyond simply following the IICRC S520 checklist and invest in understanding microbial ecology, toxicology and occupant exposure, knowledge captured in the NORMI NCRSI Level 4 framework.
They develop strong mentorship programs that emphasise technical expertise and ethical responsibility, ensuring teams appreciate why containment, documentation and verification are critical. These firms adopt a whole-environment mindset, reflecting the evolution from containment-based restoration to comprehensive biotoxin decontamination.
Lastly, they embed quality systems with measurable verification and transparent client communication. Compliance is a minimum; true quality means reproducible, health-protective outcomes. The difference between a high-performing remediation firm and one that merely “gets by” is not the equipment they own, it’s the depth of understanding behind how and why they use it.
Ultimately, high-performing remediation businesses embody the next stage of professional evolution, where the procedural discipline of the IICRC meets the scientific depth of the NORMI NCRSI model. They understand that operational excellence isn’t just technical competence, it’s the continuous integration of emerging science, ethical practice and mentoring the next generation to think beyond what’s visible.
INCLEAN: You’re also drawing on international experience, including models like NORMI. How can Australian operators take lessons from those global examples while still keeping their practices relevant to local conditions and standards?
GMS: International models like NORMI’s NCRSI protocol demonstrate the future of mould remediation, integrating microbiology, toxicology and building science into a health-focused, performance-based approach. The key for Australian operators is to adapt, not adopt wholesale.
Australia’s climate, construction materials and regulatory environment differ significantly from North America or Europe, so applying these models requires localising assessment and remediation strategies accordingly. The AS-IICRC S520:2025 provides a vital procedural framework, while the NORMI approach offers scientific depth.
Australian operators should focus on blending these: maintaining compliance with local standards and insurance requirements, while advancing environmental and health literacy through ongoing training and collaboration. This balanced integration positions Australia’s industry to lead globally, offering remediation that’s both standards-driven and scientifically comprehensive.
For those who attended the ISSA Expo, this session was a rare opportunity to see where Australian standards and global best practice meet.
