First General Services of SE Minnesota

Some types of mold can produce chemical compounds called mycotoxins although they do not always do so. In some circumstances, the toxins produced by indoor mold may cause health problems.  Many, if not most, molds can produce potentially harmful substances, whether it’s allergens, mycotoxins, or other compounds.  Hence, all indoor mold growth should be removed promptly, no matter what type(s) of mold is present or whether it can produce toxins.

http://www.health.state.mn.us/divs/eh/indoorair/mold/index.html