Stachybotrys is a mold that grows mostly fungus on media. The dark colored fungi grows on building material with a high cellulose content and a low nitrogen content. It is usually difficult to find in indoor air samples unless it is physically disturbed. Appropriate media for the growth of this organism will have a high cellulose content and a low nitrogen content. The spores are in a gelatinous mass and will die readily after release. The dead spores are still allergenic and toxigenic. The toxins are present on the fungal spores. Trichothecene and Satratoxin H have been documented as being produced by this fungus. Species of Stachybotrys have earned a considerable notoriety in recent years due to their production of potent toxins in indoor environments. They have been linked to some cases of infant death in moldy buildings.

Animals injected with the toxin from this fungus exhibited the following symptoms: necrosis and hemorrhage within the brain, thymus, spleen, intestine, lung, heart, lymph node, liver, and kidney. Individuals experiencing chronic exposure to the toxin produced by this fungus have been reported to develop cold and flu symptoms, sore throats, diarrhea, headaches, fatigue, dermatitis, intermittent local hair loss, and generalized malaise. The toxins produced by this fungus may suppress the immune system affecting the lymphoid tissue and the bone marrow. The mycotoxin is also reported to be a liver and kidney carcinogen. Affects by absorption of the toxin in the human lung are known as pneumomycosis. Percutaneous absorption has caused mild symptoms. Symptom expression, if any, may vary from individual to individual.