Moulds are Fungi and produce tiny spores to reproduce, just as some plants produce seeds. These mould spores can be found in both indoor and outdoor air, and settled on indoor and outdoor surfaces.

Some people should not remove or be present when mould is removed, including pregnant women, children and people with weakened immune systems or chronic lung diseases, such as chronic obstructive lung disease.

If you are allergic or sensitive to mould, you may develop a stuffy nose, irritated eyes, wheezing or difficulty with breathing or skin irritation. People with weakened immune systems and with chronic lung diseases may be susceptible to infections.