Contamination Control for Mould Removal

Penicillium, Hyphae And Mycelium Magnified Under A Microscope

Why It’s Important to Control Contamination During Mould Remediation

When mould is disturbed, it can release thousands of individual spores into the air. These spores are microscopic and can spread rapidly from room to room. While the spores can, in theory, remain airborne indefinitely, they will likely settle on a nearby damp spot, where they will continue to propagate. Therefore, it is very important to control mould contamination during the removal process, or it could lead to even more significant problems in time. As some remediators may overlook contamination control, what should you know about the process?

Controlling Contamination

If at all possible, any mould contamination should be contained carefully and as close as possible to its origin. This process should begin as soon as the mould is detected, and a remediator should take steps to control any amplification before removal work begins. This will help ensure that the mould does not spread from the contaminated area to nearby locations.

The mould contamination must be physically removed from the entire area rather than encapsulating or inhibiting further growth. The area cannot be considered clean if contaminated materials remain, and the whole site must be free of any dust or debris. In addition, the air should be free of that musty odour that is often associated with mould contamination.

Steps should also be taken to ensure that the area cannot be re-contaminated. The initial moisture problem must be identified and remedied as soon as possible. Any furniture or other items that need to be salvaged must be dried to an acceptable standard. The remediator should follow the latest guidance when it comes to water damage restoration.

Using the Right Tools

Remediators have a variety of tools at their disposal to help them inspect and subsequently monitor any remediation projects. For example, they can use a thermo-hygrometer to take temperature and relative humidity readings at a specific point. These readings can be taken both inside and outside the contaminated area, and action can be taken if any readings indicate the likelihood of further microbial growth. Moisture sensors can be used, which can probe individual areas for elevated moisture conditions.

Removal Methods

Before the area can be restored to its original condition, action must be taken to remove the mould from the structure, surrounding systems, or any content. There are many different methods involved, some of which are relatively new and innovative. However, all of these methods must be evaluated carefully prior to use to ensure that they are consistent with the generally accepted principles of mould remediation. Given such an assessment, the remediator can carefully consider these methods alongside the potential benefits and risks associated.

Post Remediation Materials and Methods


Many different chemical products are available, but remediators should always proceed with care. They should be familiar with the pros and cons associated with each specific product and be conscious of any individual concerns put forward by a client. In particular, the primary goal must be the removal of the mould contamination, and a remediator should not adopt the “spray and pray” approach that is used in other parts of the industry.

While certain antimicrobials are labelled for cleaning and disinfecting, they should not be used as the primary method for physical removal. Instead, the bioburden and soil should be physically removed first before any attempt to disinfect. Therefore, the antimicrobials should only be used as an aid to proper cleaning. A remediator may not even need to use antimicrobials for nonporous building materials that have been thoroughly cleaned.

Remember, antimicrobial pesticides can be harmful to humans and pets. Therefore, it’s important to follow the instructions on the label very carefully to minimise risk and potential liability. For example, these chemicals should only be used to treat microorganisms if the government agency has registered the product in relation to the type of structure or surface. Personal protective equipment may need to be worn, and remediators should comply with all safety, use or licensing requirements and be up-to-date with the applicable training.

Additionally, the remediator should talk through the potential risks and benefits with the customer and get consent in writing before they proceed. They will need to know if any pre-existing health conditions may require additional, special precautions. The customer, any other occupants or animals should leave the application site before work commences.

Fungicidal Coatings

Certain remediators may decide to use fungicidal coatings or mould resistant coating products as a primary tool. However, these products should not be used in the place of proper source removal of the mould contamination. They are also no replacement for regular cleaning or maintenance and good moisture control, even though they can provide some protection from microbial growth.

Some mould resistant and fungicidal coatings may create a vapour barrier and should be avoided at all costs, as they could lead to a build-up of moisture and issues in the future. Instead, the product should demonstrate permeability in accordance with ASTM D-1653 (minimum of 1.0 perms). The product should also be water-based, with low levels of volatile organic compounds.

Fungicidal coatings should only be applied to surfaces that have been correctly cleaned and disinfected. They should never be used to try and “seal” active mould growth. Otherwise, mould may continue to grow beneath the coating. Consequently, these coatings and sealants should only be applied once a post-remediation evaluation has been completed. Clear coatings should be used if there is any concern that the mould may re-occur so that treated surfaces can be visually inspected in the future.

Temperature Extremes

The application of extreme hot or cold temperatures should never be used as an alternative to the physical removal of mould contamination and proper cleaning.

How to Dispose of Contaminated Materials

If the material in question is not regulated (such as asbestos or lead), it can usually be disposed of as construction or compost waste. It can therefore be consigned to a landfill, but it’s important to check local laws and regulations first.

The material should be bagged or wrapped carefully and transported by a suitable vehicle to the landfill or kept secure. If any of the materials escape from containment within a building, HEPA-vacuuming processes should be initiated. Remediators may need to wear PPE in this situation. The work area should also be adequately cleaned using HEPA-vacuuming and damp wiping, including the entry and exit chamber ceilings, walls or floors.

Trusting the Experts

Mould remediation is a complicated job and should only be approached by experts. Always make sure that the remediator you chose controls contamination carefully during their work, with particular attention to the removal and disposal of contaminated materials.

Contact PureProtect at 1800 664 662