Q & A What is Stachybotrys chartarum (also known as Stachybotrys atra)? This is one of many types of black mold that may grow on water-damaged building materials. This mold requires a lot of water or moisture to grow, so finding it indoors indicates some significant moisture accumulation problems. It only grows on materials with high fiber and low nitrogen content, such as paper (including wallpaper and the paper covering of gypsum wallboard), wood or jute (frequently used for the backing of older carpets). This mold does not grow on shower tile or plastic. In the outdoor environment it is found in soil, rotting hay and leaf debris. This mold, among others, may produce mycotoxins - chemicals that discourage growth of other microorganisms and that may also cause health problems in people. What are mycotoxins? While they are growing, some molds produce metabolic products that discourage or prevent bacteria or other fungi from growing in the same area. When those metabolic products also cause health problems in animals or humans, they are called mycotoxins (myco = fungal origin). Thus, mycotoxins are natural products from molds that may cause a toxic response in vertebrates when small amounts are eaten, inhaled or touched. Molds that are capable of generating toxins (called "toxigenic mold") do not always produce them in every situation. Scientists believe that certain very specific conditions must be present for a toxigenic mold to actually produce toxins, such as the right combination of temperature, moisture, type of material the mold is growing on and, perhaps, competition from other microorganisms. Can my home (or workplace) be tested for mycotoxins? There are currently no tests available through commercial laboratories to determine if mold toxins are present in the air or on surfaces in a home or workplace. Test methods that are currently available are used for research purposes and are not applicable to home or workplace situations. Decisions to clean up mold and precautions to take during the clean-up process do not require knowledge about the presence of mycotoxins. If there is visible mold or a moldy odor in a room, then there is a mold problem that needs to be addressed (see Mold in My Home: What do I do?) Are there any tests that can tell if I have been exposed to mycotoxins? No, there are no laboratory tests of blood, urine or other body components that can determine if a person has been exposed to mycotoxins. Blood can be tested for antibodies to some specific types of fungi. However these tests only determine if a person who has become allergic to fungi has been exposed recently to that specific type of fungus. Allergy tests cannot determine if a person has been exposed to fungal toxins.