Mold Colonies
Molds (also spelled “moulds”) are simple, microscopic organisms that can grow virtually anywhere, both inside buildings and outdoors. Mold colonies can grow inside damp or wet building structures. Mold spores are a common component of household and workplace dust.
Health effects from exposure to mold can vary greatly depending on the person and the amount and type of mold present. Regardless of the type of mold, it should be treated as potentially a health hazard and should be removed from homes and workplaces.
Learn more about the following molds:
Mold Types in Homes and Their Hazard Classes
Hazard Classes of Indoor Mold
Black Mold Spores
In some countries indoor fungi have been grouped into 3 hazard classes based on associated health risk. These classes are similar to risk groups assigned to microorganisms handled in laboratory environments.
• Hazard Class A: includes fungi or their metabolic products that are highly hazardous to health. These fungi or metabolites should not be present in occupied dwellings. Presence of these fungi in occupied buildings requires immediate attention.
• Hazard class B: includes those fungi which may cause allergic reactions to occupants if present indoors over a long period.
• Hazard Class C: includes fungi not known to be a hazard to health. Growth of these fungi indoors, however, may cause economic damage and therefore should not be allowed.
Molds commonly found in kitchens and bathrooms
Cladosporium cladosporioides (hazard class B)
Cladosporium sphaerospermum (hazard class C)
Ulocladium botrytis (hazard class C)
Chaetomium globosum (hazard class C)
Aspergillus fumigatus (hazard class A)
Molds commonly found on wallpapers
Cladosporium sphaerospermum
Chaetomium spp., particularly Chaetomium globosum
Doratomyces spp (no information on hazard classification)
Fusarium spp (hazard class A)
Stachybotrys chartarum (hazard class A)
Trichoderma spp (hazard class B)
Scopulariopsis spp (hazard class B)
Molds commonly found on mattresses and carpets
Penicillium spp., especially Penicillium chrysogenum (hazard class B) and Penicillium aurantiogriseum (hazard class B)
Aspergillus versicolor (hazard class A)
Aureobasidium pullulans (hazard class B)
Aspergillus repens (no information on hazard classification)
Wallemia sebi (hazard class C)
Chaetomium spp., particularly Chaetomium globosum
Scopulariopsis spp.
Molds commonly found on window frames
Aureobasidium pullulans
Cladosporium sphaerospermum
Ulocladium spp.
Molds commonly found in basement (cellars)
Aspergillus versicolor
Aspergillus fumigatus
Fusarium spp.
Molds commonly found in flower pot soil
Aspergillus fumigatus
Aspergillus niger (hazard class A)
Aspergillus flavus (hazard class A)
For more information regarding fungal identification, please call 604-435-6555 in British Columbia or 905-290-9101 in Ontario or 1-866-813-0648 from other Provinces.