What is black mould? "Black mould" does not refer to a single type of mould. Many indoor moulds can appear black especially at advanced stage of growth when the mould produces dark pigmented spores. Some of the indoor moulds that appear black include Aspergillus niger, Ulocladium species, Cladosporium species, Memnoniella species and Stachybotrys species. Black mould is erroneously used to refer to Stachybotrys.

Are black moulds a health hazard? The colour of a mould does not determine whether it's a health hazard or not. For example, a number of species of Aspergillus are not black yet they produce highly potent toxins and/or are highly allergenic. All moulds regardless of their colour should be considered as potentially hazardous if found growing in occupied spaces (in houses or offices), on food or feed.