Symptoms with exposure to hydrogen fluoride gas are almost always acute, since hydrogen fluoride is not metabolized and is excreted in the urine. Chronic exposure to hydrogen fluoride leads to the most severe damage that occurs in the skeletal system and associated tissues. Results of chronic exposure vary from osteofluorosis to crippling fluorosis with marked restriction of locomotion. The severe symptoms require a prolonged exposure, on the order of a decade, which has not been reported in Korea (4). Chronic exposure also causes functional disabilities of the liver and kidneys. Hydrogen fluoride has not been classified for carcinogenic effects, and, since they are able to cross the placenta, at low doses is thought to be essential for normal fetal development in humans. No reproductive effects due to hydrogen fluoride are known. Thus, osteofluorosis and impairment of liver and kidneys are not expected outcomes in the 27 September 2012 accident.