sentences:  The average Amanita mushroom contains 3–5 mg of amanitoxins, so one 40–50 g mushroom could kill an average adult.The U.S. Occupational Safety and Health Administration (OSHA) permits a time-weighted average exposure of up to 5 mg/m3 of β-amanitin dust.β-amanitin may cause irritation of the respiratory tract, headache, dizziness, nausea, shortness of breath, coughing, insomnia, diarrhea, gastrointestinal disturbances, back pain, urinary frequency, liver and kidney damage, or death if ingested or inhaled.