Hydrogen fluoride exists as a liquid under 19.5℃ and has a strong irritating odor (1). The gas and liquid forms can contact and damage the eyes and skin, and the respiratory tract can be damaged by inhalation of the gas form. Reaction to the exposure can be immediate and symptoms appear within 3 days at the latest. Temporal shortening of breath and/or respiratory stimulation symptoms such as coughing are initiated. Contact with the eyes or skin causes symptoms ranging from irritation to severe burn. Digestion with the gastrointestinal tract causes irritation and tissue damage of the oral cavity, esophagus and stomach. Exposure to high concentrations of hydrogen fluoride causes hypocalcaemia and hypomagnesaemia, which can be lethal due to ventricular fibrillation caused by hyperkalemia or pulmonary edema