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. And 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.
Here are common types of mold found in homes and businesses:
Common Mold Types Found in Homes and Their Hazard Classes
Hazard Classes of Indoor Mold
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, commonly called ‘black mold‘ (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)
Mold & Bacteria Labs provides a professional and comprehensive laboratory testing service. For more information regarding fungal identification, please call 905-290-9101 in Ontario or 1-866-813-0648 from other Provinces.