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What is mould?

Mould (or mold) refers to fungi that grow in the form of multicellular thread-like structures named hyphae.

One question we get asked on a regular basis is what is the difference between mould and mildew?

Mildew is generally white, yellow or grey and grows on the surface of moist, warm areas. It has a powdery type texture.

Mould is usually green or black with a more slimy texture and generally grows under the surface of anything that is wet or moist.


What about black toxic mould?

There is a difference between the colour of mould and its toxicity.

Just because a mould is black, does not mean it is toxic and not all black moulds are lethal.

Known as Stachybotrys chartarum black toxic mould is dark black or sometimes dark green and is very much a highly toxic form of mould.

Black toxic mould releases mycotoxins which are toxic chemicals present in mould spores that get released into the air and can then be inhaled.


The health impact of mould in humans

As a general rule mould will not cause infection in healthy people, with most health effects being allergy related, including:

  • Asthma
  • Headache
  • Nausea
  • Exhaustion
  • Nose bleeds
  • Burning eyes
  • Cognitive disorders


What causes mould?

Mould essentially needs 3 things to flourish:

  1. A source of water
  2. A source of food
  3. A source of air

It will come as no surprise that mould thrives in damp areas, which are most often the result of one or more of the following occurring in the affected area:

  • Water ingress
  • Flooding
  • Condensation
  • Leaks
  • Capillary action – otherwise known as rising damp
  • Steam
  • Lack of ventilation


Water categories and their impact on your health

If you have noticed mould on your premises it is important to understand the source of the water that is contributing to the mould growth.

Different water sources have different categories and can impact the risk to your health depending on where the water is coming from.

There are 3 basic categories of water:

Category 1 (Clean) – this originates from a sanitary source and poses no substantial risk. However, it is important to know that it may not always remain clean after it comes into contact with other surfaces or materials.

Category 2 (Grey) – this water comes from discarded water from machinery, for example a washing machine, and contains significant contamination and has the potential to cause discomfort or sickness. It may contain potentially unsafe levels of microorganisms.

Category 3 (Black) – generally known as sewage, this water is grossly contaminated and may contain pathogenic, toxigenic or other harmful agents.


Assessing mould in your home or office

If you notice mould build up in any area it is important to contact a professional to have it correctly dealt with, however there are some things you can do to initially assess the risk, these include:

  • Source of the water – is it category 1, 2 or 3. If it is category 2 or 3 the risk presented is more severe.
  • Use of the building – how much time do people spend in the area? If it is heavily used then your need to resolve the issue becomes more urgent.
  • Health of the occupants – have you already noted any symptoms of mould-related illness? If so that is a clear indication that the issue needs to be dealt with immediately.
  • Persistence of mould – have you cleaned the mould previously but it has returned? This indicates the cause of the mould has not been sufficiently rectified.


Mould testing & remediation

One of the most common issues with mould is not addressing the original cause of the mould and simply masking the problem for a short period of time through cleaning the area.

Engaging an independent professional to conduct a thorough assessment of the affected area and create a remediation plan is the best course of action.

When choosing the right contractor to engage consider the following:

  • Qualifications – do they have the correct and most up to date credentials?
  • Experience – do they have a proven track record and suitable experience?
  • Independence – are they working for a third party rather than you? For example have they been engaged by your insurance company?
  • IICRC Method - The IICRC, or the Institute of Inspection, Cleaning and Restoration Certification, is the non-profit certifying body for the cleaning and restoration industry.


Pre-remediation testing – what to expect

If you have found the right contractor as listed above, you should expect two things from them as part of the initial assessment:

  1. Aid in determining safety of affected area

This is where they will consider the extent of the mould and the specific species of the mould. They will also conduct moisture, surface and air testing.

  1. Produce a scope of works for remediation/removal

This is where the contractor will outline exactly what they plan to do to both remove the mould and the action required to ensure it does not return.


Remediation – how to remove mould

The cleaning process for removing mould always involves one key ingredient – good old fashioned elbow grease!

However there are some biocides that can help too, these include:

  • Soapy water
  • Bleach
  • Chlorine dioxide
  • Quaternary ammonium compounds
  • Vinegar
  • Tea tree oil

Wearing the correct safety equipment is essential during the remediation phase, so it is important to take the appropriate precautions and use the following when cleaning the mould affected areas:

  • P2 mask or respirator
  • Gloves
  • Safety goggles
  • Coveralls

The final phase of mould remediation is the drying stage, completely this correctly is essential to ensure the mould does not return after the cleaning process.


There is no secret to drying the area, as long as we can get either heat or air movement in the area, ideally both.

We can use something as simple as a pedestal fan all the way to an industrial size heater, the most important thing is that the area is left sufficiently dry.


Post remediation inspection – what to look for once the mould is removed

Once the mould remediation is complete it is important to ensure the following has been addressed:

  • Source of moisture rectified – this is essential, was the original cause of the mould sufficiently resolved?
  • Works complete – did the contractor complete the work as scoped?
  • No odour – Has the ‘must’ like smell gone? If it still smells mouldy then there could still be an issue.
  • No visible mould – Has the mould been sufficiently removed? Can you see areas where mould still exists?
  • Dry areas – Is the area completely dry?
  • No health complaints – Over the coming weeks and months monitor the health of those who use the area and be on the lookout for any symptoms related to mould inhalation or exposure.

Our qualified staff are very experienced in dealing with outbreaks of mould and can help with the identification and remediation of any mould outbreak.

For more information, or to book your consultation contact us today.

We also recommend you download our latest whitepaper: Mould Causation, Prevention & Remediation to learn more.


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