What is Black Mould?
Stachybotrys chartarum, also known as black mould, is a highly toxic greenish-black, slimy substance that grows in moisture damaged buildings. Not all black moulds are toxic and not all toxic moulds are black, but the toxic variety of black mould is considered responsible for asthma, bronchitis and lung disorders. It is also associated with nasal stuffiness, wheezing, skin and eye irritations. It has been associated with the death of infants in the 1990s, but mainly affects people with weak immune systems.
Cladosporium is a non-toxic black mould that is found inside and outside of buildings. For most people who come into contact with this type of black mould, there are no ill effects, but there could be symptoms of increased allergic reactions and asthma symptoms from constant heavy exposure.
There is some variety of black mould in almost every type of building, and it may be difficult to distinguish if it is toxic or not without having it tested in a laboratory. It is wise to treat all black moulds as if they are toxic, and even if they are not, it is not healthy to have any type of mould in the home.
Mould spores attach themselves to a variety of hosts to travel to different areas. Hosts include humans, animals and shoes. It is also carried by air through open doors and windows. When spores land in moist areas they multiply rapidly. The most common place for black mould to develop is in a part of a building where there is a leak in the roof, water seepage in a basement or a leak in a window casement when it rains. It can grow on insulation, drywall, ceiling tiles, soaked wood, cardboard and damp cotton clothing. Black mould looks wet and shiny in appearance and will smear if it is touched. It also feels slimy.
Before beginning to clean an area covered in black mould, the extent of the infestation needs to be ascertained. If the area is small and the result of a small leak or plumbing problem, it can be disinfected with bleach. A ratio of one cup of bleach to four litres of water is sufficient to kill the mould. Adding dish soap to the mixture will help removing any accumulated grime in the area. After the bleach mixture has saturated the black mould for 15 minuets, it can be cleaned. Then the area needs to be thoroughly dried and any leak repaired, so the problem does not return.
If a leak has been repaired or for any other reason the black mould has not had any moisture it will dry. These dry mould spores are very dangerous, and the area should not be scratched or scraped in an effort to remove them. This will release the spores into the air where they can be inhaled.
A professional mould remover will be necessary if the black mould has infiltrated the insulation in the walls or the floor boards and carpet. Any infested area that is larger than two feet is considered heavily infested with black mould and needs professional attention.