Hydrofluoric acid damaged skin

Hydrofluoric acid is highly corrosive to skin and mucous membranes. Even in fairly low concentrations, it causes painful skin burns and severe damage to eyes and the respiratory system. Exposure at higher levels results in destruction of tissues and death. No one in l e.xas City was exposed to more than trace concentrations of hydrofluoric acid. The acid vessel had a capacity of about 850 barrels of which a small fraction was released. 

Hydrofluoric acid HF Commercially available concentrated acid is 50% (26 M) HF must be stored in plastic containers, since it attacks glass very damaging to skin Dissolving silica-based materials and stainless steel... 

Both anhydrous hydrogen fluoride gas and hydrofluoric acid are highly corrosive and dangerous. Skin contact by even dilute aqueous HF can be severely injurious, causing deep ulceration with delayed effect. The acid can penetrate the skin and destroy tissues. It also is damaging to eyes, nose and lungs. Inhalation can cause fluorosis and pulmonary edema. 

Gas severely irritates the respiratory system and eyes. It irritates the skin and painful burns may develop after an interval. The liquid causes severe, painful burns on contact with all body tissues. Swallowing results in immediate and severe internal irritation and damage. The treatment of hydrofluoric acid burns has been described.5 Prevent inhalation of gas. Prevent contact with skin, eyes, and clothing.2 TLV-STEL-C (as F) 3 ppm (2.6 mg/m3).6... 

Hydrofluoric acid finds occasional use in conjunction with other acids in attacking steels that dissolve with difficulty in other solvents. Because hydrofluoric acid is extremely toxic, dissolution of samples and evaporation to remove excess reagent should always be carried out in a well-ventilated hood. Hydrofluoric acid causes serious damage and painful injury when brought into contact with the skin. Its effects may not become evident until hours after expo.sure. If the acid comes into contact with the skin, the affected area should be immediately washed with copious quantities of water. Treatment with a dilute solution of calcium ion, which precipitates fluoride ion, may also be of help. 

The toxicity of hydrofluoric acid did not go unnoticed amongst the early chemists working with this material. The vapours were known to be corrosive and incautious inhalation can produce many damaging effects. Contact with the skin is also gravely dangerous, a problem difficult to avoid as the acid rapidly produced holes in, and escaped from, apparatus designed to produce and contain it. 

When organic solvents are used, the effective dermal resorption must be controlled by means of suitable protective measures. The degreasing effects of solvents increase the dermal resorption of chemicals as a consequence of damage to the skin barrier. Chemicals which can be absorbed percutaneously and which have caustic effects are incorporated extremely quickly and effectively through the skin. Fatal accidents with hydrofluoric acid and phenol are well known in the literature, the chemical incorporation being effectively increased by the caustic effect of these compounds. Lethal amounts of these substances can be incorporated within a short period of time. 

Hydrogen fluoride and hydrofluoric acid are very corrosive and additionally very toxic. This synergism is responsible for their extreme danger in consequence of their very corrosive property the skin is damaged immediately and the compound very quickly reaches the target organ and can develop very toxic effects. Therefore,... 

There are several major classes of corrosive substances. Strong acids such as nitric, sulfuric, and hydrochloric acid can cause serious damage to the skin and eyes. Hydrofluoric acid is particularly dangerous and... 

Toxicity Boron trifluoride (and organic complexes such as Bp3-etherate) are extremely corrosive substances that are destructive to all tissues of the body. Upon contact with moisture in the skin and other tissues, these compounds react to form hydrofluoric acid and fluoroboiic acid, which cause severe burns. Boron trifluoride gas is extremely irritating to the skin, eyes, and mucous membranes. Inhalation of boron trifluoride can cause severe irritation and burning of the respiratory tract, difficulty breathing, and possibly respiratory failure and death. Exposure of the eyes to BF3 can cause severe burns and blindness. This compound is not considered to have adequate warning properties. Boron trifluoride has not been found to be carcinogenic or to show reproductive or developmental toxicity in humans. Chronic exposure to boron trifluoride gas can cause respiratory irritation and damage. 

Patients with severe and extensive skin damage and/ or with systemic symptoms after exposure to corrosive agents should be treated in intensive care units. It should be noted that hydrofluoric acid or chromic acid exposure affecting only 1% of the total body surface of a person means risk of severe systemic effects. Hospitalization is also recommended for persons who have concurrent illnesses, implying that they are high-risk patients, as weU as for persons with chemical burns on the hands, feet, and perineum (Andersen 1990 Chan et al. 1995). 

Weak acids often have a toxic counterion, while few H are released and, consequently, the corrosive damage remains limited. This is particularly the case with hydrofluoric acid whose pK expresses low dissociation (pK=3.2). The importance of skin lesions is related to the association of a superficial destruction of the skin barrier by H+ allowing the fluoride ions (F ) to penetrate tissues and express their severe cytotoxicity (see Sect. 4.1.2.1). 

Even if it is a partially dissociated acid (p/fa=3.2), all safety managers and company doctors, toxicologists, as well as workers know what hydrofluoric acid (HE) can do on skin. It can induce more severe damages than all other strong acids. It is due to its double danger, corrosive because of the acidic (H ) ions and toxic because of the fluoride (F") ions that can bind cellular calcium and magnesium. H+ ions create a superficial destruction of the epidermis layer allowing F toxic ions to penetrate deeper in the skin [6, 257]. 

Skin corrosive Causes severe skin burns and eye damage lA, IB, 1C Danger Produces destruction of skin tissue -visible necrosis of epidermis and dermis Sodium hydroxide, potassium hydroxide, sulfuric acid, hydrofluoric acid, nitric acid... 

Wafer cleaning uses strong acids and oxidizer mixtures, including piranha etch, to clean away any organic materials adhering to the wafer. Hydrofluoric acid is used to remove any oxide on the wafer. These processes are conducted in a wet-process hood to control vapor off-gassing and with substantial personal protective equipment to avoid contact with these corrosive and reactive materials. Acid exposure by vapor causes severe irritation of the upper respiratory tract. Eyes and mucous membranes exposed to acid vapors can be damaged and exposures to nitric acid can discolor the cornea and skin. 

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