Mould fungi
The organisms behind the marking. Around 1.5 million species, each with its own conditions — and killing them does not end the exposure they created.
Precautions
- Ventilate the area
- Wear gloves
- Wear eye protection
- Consider professional help
In detail
Mould is the common term for a downy or furry growth on organic matter, caused by fungi. The organisms are simple-celled, do not need light, and bear microscopic spores produced in enormous quantities. The federal conservation guidance puts the species count at approximately 1.5 million, each requiring different conditions to survive, which is why no single statement about temperature or humidity covers all of them. Two of its findings change what treatment means. The first is that extreme cold, freezing and heat DEACTIVATE spores or spore growth but do not kill them, and that spores can be reactivated when temperatures rise again. The second is blunter: killing mould does not eliminate all health hazards, because inactive mould may still cause allergic reactions in sensitive people. A treated colony left in place is therefore still an exposure, which is the argument for removal over treatment wherever removal is possible. A third finding reaches metal: as a by-product the fungi produce organic acids that corrode and etch inorganic materials, and excrete pigments, digestive enzymes, odours, allergens and toxins.
What works
Moisture control is effective against Mould fungi Strongly supported
It denies the spores the water they need to germinate. It does not kill them, and the source says so in the same document.
Dusting is effective against Mould fungi Supported
Removing the dirt removes the food. It is preventive rather than curative, and it will not touch established growth.
Why
- Mould fungi is explained by Organic load
- Mould fungi is explained by Moisture control and recurrence
- Mould fungi is explained by Biofilm
Aftercare and prevention
- Moisture control helps prevent Mould fungi
- Dusting helps prevent Mould fungi
Hacks and claims involving this
- Freezing kills mould Does not work
- Killing the mould solves the problem Does not work
Sources for this page
Sources
Conserve O Gram 3/4: Mold — Prevention of Growth in Museum Collections
National Park Service, US Department of the Interior, 2007 · Government or regulator
Relied on for: That mould is caused by fungi bearing microscopic spores, that approximately 1.5 million species each require different conditions, that extreme cold, freezing and heat deactivate spores without killing them and spores can be reactivated, that killing mould does not eliminate all health hazards, and that fungi produce organic acids which corrode metals. (states this directly)
United States Environmental Protection Agency (EPA) · Government or regulator
Relied on for: That the moisture problem must be corrected or growth returns, and that colonised porous materials may need to be discarded rather than cleaned. (states this directly)