'Most mould is visible' and other mould myths

It's hard to fathom that something so common, normal even, and seemingly harmless can be so devastating to your health.

Here are some facts if you - or someone unconvinced close to you, need more information.

• Myth – Mould is visible

  • Fact – 80% of mould is invisible. A pinprick from an inner wall or ceiling infested with mould is enough to contaminate a large space

• Myth – A musty or mouldy smell indicates mould growth

  • Fact – A mouldy or musty smell comes from M-VOCs (microbial volatile organic compounds) and is not toxic. But the secondary metabolites it often emits e.g. mycotoxins, are toxic. The smell is thus a good indication of mycotoxin off-gassing

• Myth – Bleach kills mould

  • Fact – Bleach is high pH rendering it ineffective for killing mould, instead bleaching its colour for a few weeks. Mould actually has a defence membrane against bleach, not just rendering it inert but using it as a food! Use a mix of 80% white vinegar and 20% water instead

• Myth – Drying the mouldy area gets rid of the problem

  • Fact – If the source of the moisture or water is not fixed e.g. a leaking pipe, wet shower recess, roof leak, salt damp, the mould problem will remain. While drying the area and using dehumidifiers may slow the growth, mould is still present and can off-gas myco-toxins

• Myth – Mould only grows in wet areas

  • Fact – Mould only needs moisture to start growing. It will then continue to grow taking moisture from the air – anything more than 4% relative humidity is sufficient, and lower humidity can only be achieved artificially