Fix the moisture source (leaks, condensation, humidity)
Wear PPE: N95/FFP2 respirator, gloves, eye protection, long sleeves
Ventilate the area (open windows/doors or use fans exhausting outdoors)
For small, non-porous mold: scrub with detergent and water, then disinfect
Use one of these disinfectants on non-porous surfaces:
3% hydrogen peroxide
70% isopropyl alcohol
EPA-registered mold cleaner/disinfectant (follow label)
For porous materials (drywall, ceiling tiles, carpet, insulation): remove and discard if moldy
Do not dry-clean or vacuum moldy porous materials unless using a HEPA-filter vacuum
Bag and seal removed materials; take out promptly
After cleaning/disinfection, dry completely (dehumidifier, fans)
Check hidden areas (behind walls, under sinks, HVAC condensate lines)
If the area is large (generally over about 10 sq ft / 1 sq m), or mold is recurring, consult a professional
Avoid mixing chemicals (especially bleach with ammonia or acids)
Keep people and pets away until the area is cleaned and dry
If you have asthma, allergies, are immunocompromised, or pregnant, avoid cleanup