Glossary
Mold
Mold is a type of fungus that grows on damp surfaces. Indoors, the most common molds are Cladosporium, Penicillium and Aspergillus.
Why the names matter
Mold is a fungus, and it grows on damp surfaces indoors and outdoors. The most common indoor molds are Cladosporium, Penicillium and Aspergillus.
The names people use most often are not scientific categories. EPA explains that black mold is not a species or a specific kind of mold, and neither is toxic mold. Both are media shorthand for molds that may produce mycotoxins, or specifically for Stachybotrys chartarum.
Names you will see
Cladosporium, Penicillium, Aspergillus
The molds CDC lists as the most common indoors, and cleanup is the same.
Black mold
Not a species or a specific kind of mold. EPA calls it media shorthand.
Toxic mold
Also not a species. The term is shorthand for molds that may produce mycotoxins.
Related terms
Used on these pages
Sources
- CDC AboutAccessed 2026-09-26
- U.S. EPA Mold course chapter 1Accessed 2026-09-26
- CDCAccessed 2026-09-26