Color is not the risk scale: the CDC says damp, moldy environments may cause stuffy nose, sore throat, cough, wheeze, burning eyes, or rash, worse with allergies, asthma, or weak immunity, and that guidance applies to all mold.
The most common indoor molds are Cladosporium, Penicillium, and Aspergillus, and the advice never changes by species: remove what you see or smell and fix the moisture. Scrub hard surfaces with detergent and water and dry fully, throw out moldy porous materials, and call professionals for big areas, sewage damage, or vulnerable occupants. Mention mold exposure to your GP if chest symptoms track with a damp room.
What to do
Common questions
Is black mold dangerous?
Black mold has a scary reputation that outruns the evidence. The CDC's position is that exposure to damp and moldy environments may cause various health effects or none at all: for some people mold causes a stuffy nose, sore throat, coughing or wheezing, burning eyes, or skin rash, with worse reactions in people with mold allergies, asthma, or weakened immune systems, and that applies to mold generally, not one sinister black species. The famous toxic black mold name refers to Stachybotrys chartarum, but the CDC lists Cladosporium, Penicillium, and Aspergillus as the most common indoor molds, and official guidance is the same for all of them: color does not change the advice. If you see or smell mold, remove it and fix the moisture problem, says the CDC. The practical rules: small patches on hard surfaces clean off with detergent and water, drying completely afterward; porous materials like carpet and ceiling tiles may need throwing out, per EPA cleanup guidance; and areas over about 10 square feet, anything from sewage or flooding, or homes with asthma, allergy, or immune problems are the professional-help territory. Anyone with chest symptoms that track with a damp room should mention the mold exposure to their GP.