The Invisible Shield: Why a HEPA Air Scrubber is Non-Negotiable in Mould Remediation

a photo of AAA Mould removal hepa air scrubbers on a job site at Sylvania Sydney

When cleaning mould, what you disturb is far more dangerous than what you see. As you wipe or scrub a mouldy surface, the colony releases an invisible cloud of millions of microscopic spores and mycotoxins into the air. This aerosolized storm is the primary cause of cross-contamination and the main reason why DIY mould cleaning often fails, spreading the problem into every corner of your home.

As you wipe or scrub a mouldy surface, the colony releases an invisible cloud of microscopic spores and mycotoxins into the air, a risk supported by recent findings in Toxics (Lemke et al., 2023) that show how physical disturbance of mould can lead to airborne contamination with toxic compounds (Lemke et al., 2023).

This is where professional-grade technology becomes essential. At AAA Mould Removal, we know that the most critical tool in our arsenal isn't a chemical—it's the HEPA air scrubber. Understanding how we use this machine is key to understanding the difference between a superficial cleanup and a truly safe, professional remediation.

The reference comes from a peer-reviewed Japanese study conducted in 2018:

Hashimoto & Kawakami (2018) investigated how effectively a portable HEPA air purifier fan reduced airborne fungi in six homes. They reported:

“The number of airborne fungi decreased between 1.5 and 6 times faster when the air purifier fan was on than when it was off (spontaneous decrease)”

The Problem: You Can't Kill an Airborne Toxin

As we’ve discussed before, you cannot “kill” the toxic by-products of mould (mycotoxins). These chemicals, along with allergenic dead spores, become airborne the moment the mould is disturbed. Without a system to capture them, they will travel on air currents, settling on your furniture, clothes, and deep inside your ventilation system. This is how a small bathroom mould issue becomes a whole-house contamination event.

The solution is not to try and spray these particles out of the air. The solution is to capture them completely.

The Professional Solution: Containment, Negative Air, and Air Scrubbing

A true professional never works on a mould problem in an open environment. The first step is always to manage the air.

1. The Contained Work Zone: We use heavy-duty plastic sheeting to build a fully sealed enclosure around the contaminated area. This containment chamber isolates the mould and prevents physical drift of dust and debris.

2. The HEPA Air Scrubber: Inside this chamber, we run one or more powerful air scrubbers. These are not your average home air purifiers. A professional air scrubber is a high-volume fan connected to a series of filters. The final and most important filter is the HEPA (High-Efficiency Particulate Air) filter. By definition, a true HEPA filter is certified to capture 99.97% of all particles as small as 0.3 microns. Given that mould spores are typically 3-40 microns in size, they are easily trapped.

3. Creating Negative Air Pressure: This is the crucial step that makes the system work. We strategically place the air scrubber so that its filtered air is ducted outside the containment zone. This action pulls air out of the chamber, creating a vacuum effect known as "negative air pressure." This ensures that clean air from the rest of the house is drawn into the contained area and that no contaminated air can possibly leak out. It effectively turns the entire workspace into a giant, inward-facing vacuum cleaner.

   
   

Are All Air Scrubbers Created Equal?

There's a significant difference between the equipment we use and the devices marketed for home use:

• Professional Remediation Scrubbers: These are robust, high-CFM (Cubic Feet per Minute) machines designed to filter a massive volume of air quickly. They are built to handle the heavy particle load of an active remediation job and have multiple filter stages: a pre-filter for large dust, an optional carbon filter for odours and VOCs, and the final, medical-grade HEPA filter.

• Home Air Purifiers: While excellent for maintaining good indoor air quality day-to-day, these smaller units lack the power to handle the sheer volume of spores released during a cleanup. More importantly, they cannot be configured to create the negative air pressure that is essential for preventing cross-contamination.

  
  

  As required by the ANSI/IICRC S520 standard, professional remediation uses HEPA‑filtered Air Filtration Devices (AFDs) to create negative air pressure of at least 5–7 Pa, ensuring no airborne contaminants escape the containment zone

  
  

The Most Important Part of the Job: Cleaning the Cleaner

What happens to the machine after it has spent hours sucking up millions of mould spores? The air scrubber itself becomes a containment risk if not handled correctly.

As part of every job, AAA Mould Removal follows a strict decontamination protocol:

1. Filter Removal: While still inside the contained work area and wearing full Personal Protective Equipment (PPE), our technicians carefully remove all filters.

2. Safe Disposal: The contaminated pre-filters and the HEPA filter are immediately placed into sealed disposal bags. They are treated as contaminated waste and removed from your property.

3. Machine Decontamination: The interior and exterior surfaces of the air scrubber unit are meticulously wiped down and sanitised.

4. New Filters for Every Job: We install a complete set of brand-new filters before the machine is used on its next project. This guarantees there is zero chance of bringing contaminants from a previous job into your home.

   
   

Your Safety is Our Priority

Throughout this entire process, our team wears full PPE, including P2/N95 respirators, eye protection, and gloves. This is a non-negotiable standard to protect our health and ensure we don’t track any contaminants out of the work zone.

Managing airborne particles is the definitive mark of a professional mould remediator. It requires the right knowledge, the right process, and the right equipment.

At AAA Mould Removal, we believe an informed client is a safe client. That is why we offer a free, no-obligation mould site assessment. We will visit your property, inspect the issue, and provide clear guidance on how to safely and effectively remove the mould, explaining the specific equipment and containment procedures your situation requires.

Don’t risk an invisible storm of mould spores in your home. Contact the certified professionals who know how to control the air you breathe.

About the Author

Michael Nguyen is the founder and lead technician at AAA Mould Removal, one of Australia's trusted mould remediation companies. With industry certifications including IICRC Water Damage Restoration, Applied Microbial Remediation, and Applied Structural Drying, Michael brings expert knowledge and proven techniques to every job.

He is also a licensed builder and carpenter, holding a Diploma in Building & Construction, which gives him a deep understanding of how moisture and structural conditions contribute to mould growth in homes and buildings. Michael specialises in residential and commercial mould removal, black mould treatment, water damage restoration, and structural drying.

Currently studying a double Bachelor’s degree in Medical Science and Environmental Science at Macquarie University, Michael combines scientific expertise with hands-on experience to deliver safe, thorough, and lasting mould removal solutions. His mission is to help homeowners and property managers maintain healthy indoor environments with professional mould remediation services across Sydney and surrounding regions.

Learn more at www.aaamouldremoval.com.au or call today for a free mould inspection and quote.