Black mould is not only unsightly, but also dangerous. If left untreated, the toxic properties of black mould can lead to breathing problems and even death in extreme cases. Black mould is much more difficult to clean than other types of mould, as its spores spread easily, leading to growth in nearby areas. Porous materials that develop black mould should be carefully disposed of. Windows should be cleaned carefully.
Gather all your materials before you begin. Once the room is sealed, you will not be able to unseal it until the cleaning process is complete.
Seal off the room where the window is, if the mould is on the inside of the window. Use plastic sheets and sealing tape to cover windows, doors, and other openings.
Turn off any heat or air conditioning to prevent air flow throughout the house.
Wear protective clothing. Wear plastic gloves, a dust mask, and goggles. Make sure clothing covers as much skin as possible and can be easily removed.
Spray the window with water. Wetting the mould will help prevent the mould spores from spreading around the room.
Mix two or three drops of liquid dish soap with a gallon of hot water in a bucket. Use an abrasive sponge to scrub as much of the mould from the window as possible.
Clean the window with disinfectant. Read the label to make sure the product is approved for use with toxic mould, and follow all manufacturer's instructions.
Dry the window with a towel. Use a hair dryer to make sure all seals are completely dry.
Inspect the window to ensure no mould is visible.
Unseal the room. Place the plastic sheets, as well as the gloves and sponge, into a plastic bag to be thrown away. Remove and wash protective clothing.
Inspect the window periodically to make sure the mould has not returned.