What are the hazards of hydrofluoric acid to the human body?

Introduction to Toxicology: Hydrofluoric acid exhibits strong irritation and corrosivity to the skin. The hydrogen ions present in hydrofluoric acid have dehydrating and corrosive effects on human tissues, while fluorine is one of the most reactive non-metallic elements. Upon contact with hydrofluoric acid, fluoride ions continuously dissociate and penetrate deep into tissues, dissolving cell membranes and causing liquefactive necrosis of the epidermis, dermis, subcutaneous tissue, and even muscular layers. Fluoride ions can also interfere with the activity of enolase, inhibiting the oxygen uptake capacity of skin cells. It is estimated that ingesting 1.5 grams of hydrofluoric acid can cause immediate death. Inhaling high concentrations of hydrofluoric acid mist can lead to bronchitis and hemorrhagic pulmonary edema. Hydrofluoric acid can also be absorbed through the skin, causing severe poisoning.    
 Clinical Manifestations: The extent of skin damage is related to the concentration of hydrofluoric acid, duration of exposure, site of exposure, and treatment methods. The higher the concentration and the longer the exposure time, the softer or denser the affected tissue becomes, and the more rapid and intense the effect. When exposed to hydrofluoric acid with a concentration of over 30%, pain and skin damage often occur immediately. When exposed to low concentrations, pain and skin burns often appear after several hours. Local skin lesions initially present as erythema, followed by white edematous areas with red discoloration, then turn into pale bluish-gray necrosis, and finally covered with thick brown or black scabs, which later form ulcers after the scabs fall off. Damage to the fingers often transforms into bullae, and the nail plate is often simultaneously affected, with redness and swelling around the nail bed and peronychia. In severe cases, subungual blisters form, and the nail bed separates from the nail plate. High-concentration burns often present as progressive necrosis, with slow healing of ulcers. In severe cases, local bones, especially phalanges, are affected. Manifestations include narrow interphalangeal joints, rough articular surfaces, irregular edges, cortical hyperplasia, narrow medullary cavities, and even bone resorption, similar to signs of osteomyelitis. Hydrofluoric acid mist can cause skin itching and dermatitis. In high doses, it can also cause burns to the skin, gastrointestinal tract, and respiratory mucosa. After eye contact with high-concentration hydrofluoric acid, there is severe local pain and rapid formation of white pseudomembranous opacity. If not treated promptly, corneal perforation can occur. Hydrofluoric acid burns combined with fluorosis have attracted attention. Patients may experience convulsions due to hypocalcemia, prolonged Q-T interval on electrocardiogram, and episodes of ventricular fibrillation.