Aw - 0.94 , optimum Aw ->0.98. Several strains of this mold (S. atra, S. chartarum, and S. alternans are synonymous) may produce macrocyclic trichothecenes (one of which is Satratoxin H) that are poisonous by inhalation. These mycotoxins, when present, are primarily associated with the mold's spores.
Individuals with chronic exposure to Stachybotrys's toxins reported cold and flu symptoms, sore throats, diarrhea, headaches, fatigue, dermatitis, hair loss, general malaise, and psychological depression. For infants, the toxins create a vulnerability to a serious condition called pulmonary hemosiderosis (bleeding in the lungs) where severe bleeding can result in coughing blood or nosebleeds, and low grade bleeding can cause chronic coughs and congestion with anemia. People who unknowingly handled material contaminated with this mold described symptoms of cough, rhinitis, burning sensations of the mouth and nasal passages, and cutaneous irritation at the point of contact, especially in areas of abundant perspiration. The toxins produced by this mold will suppress the immune system, affecting the lymphoid tissue and the bone marrow. Animals injected with macrocyclic trichothecenes exhibited the following symptoms: necrosis and hemorrhage within the brain, thymus, spleen, intestines, lung, heart, lymph nodes, liver, and kidneys.
This is a dark-colored fungus that grows on building materials with a high cellulose content and a low nitrogen content. It is slow growing when compared to other common molds, and may not appear to compete well in their presence. Yet, when moisture levels are high for prolonged periods, Stachybotrys may gradually become the dominating genus (possibly because of its yield of mycotoxins, which are believed to be directed against other molds and bacteria). This organism is usually difficult to find in indoor air samples unless it is physically disturbed, but when it does appear it is an alert to find the source, as it will likely be found growing in abundance. Its spores--which can be found in a gelatinous mass--will die readily after release, but are still allergenic and can be toxigenic. Areas with a relative humidity above 55%, and are subject to temperature fluctuations, are ideal for toxin production.