Cladosporium
Cladosporium is among the most common molds in the world and a frequent indoor find on cool, damp surfaces such as window frames, bathroom tile and fabrics. It is chiefly relevant as an allergen.
At a glance
- Appearance
- Olive-green to brown/black, suede-like
- Loves
- Cool damp surfaces, window frames, fabrics
- Mycotoxins
- Not a major mycotoxin producer
- Key action
- Reduce condensation and humidity
The short answer
Cladosporium is a very common olive-green to brown mold that grows on cool, damp indoor surfaces — window frames, bathroom grout, HVAC and fabrics. It is a leading airborne allergen but is not considered a major mycotoxin producer. Reducing condensation and humidity is the main control.
What is Cladosporium?
An extremely common mold genus that grows on cool, damp surfaces indoors and is a major source of airborne allergens.
Quick summary
- One of the most common molds worldwide.
- Grows on cool damp surfaces and fabrics.
- A leading airborne allergen.
- Not a notable mycotoxin producer.
This information is educational and does not diagnose or treat any condition. It is not for emergencies. If you have trouble breathing, chest pain, fainting or other severe symptoms, call your local emergency number right away.
Where it grows
Cladosporium forms olive-green to brown or black colonies with a suede-like texture. It tolerates cooler conditions than many molds, so it appears on window frames with condensation, bathroom surfaces, painted walls, HVAC components and damp fabrics.
Health context
Cladosporium is a major source of airborne mold allergens and can trigger hay-fever-type symptoms and asthma flares in sensitized people. It is not regarded as a significant mycotoxin producer, so its indoor importance is primarily allergic.
Key point: Think of Cladosporium mainly as an allergen and a sign of condensation or dampness.
Controlling it
Reduce condensation by insulating cold surfaces, improving ventilation in bathrooms and kitchens, and keeping humidity in the 30–50% range. Clean affected hard surfaces and address the moisture that allows regrowth.
Key takeaways
- Cladosporium is a very common allergen mold.
- It favors cool, damp surfaces and condensation.
- It is not a major mycotoxin producer.
- Condensation and humidity control keep it away.
Frequently asked questions
Why does Cladosporium keep coming back on my windows?
Cool window surfaces collect condensation, and Cladosporium tolerates cool damp conditions well. Reducing condensation — through insulation, ventilation and lower humidity — is the durable fix.
Free mold-risk assessment
Turn your symptoms and environment into clear next steps in minutes.
Start freeBook a consultation
Get physician-supervised testing and a personalized recovery plan.
See programsReferences & further reading
This article is for general education only and does not diagnose, treat or replace care from your own licensed clinician. MoldDetox.ai provides physician-supervised, educational health services. It does not provide emergency care. Testing and recommendations support — but do not replace — evaluation by your own licensed clinician.