A comparison of calcium gluconate and Zephiran for the treatment of dermal hydrofluoric acid exposure

Abstract

Hydrofluoric acid (HF) is an aqueous form of hydrogen fluoride (Lewis, 1993) that typically emits a colorless or fuming irritate gas at room temperature (Hance, Solomon, Salmon, Fall, & Cass, 1997). As one of the more commonly used inorganic compounds in industry today, hydrofluoric acid is highly corrosive and will deteriorate materials such as concrete, glass, natural rubber, and metal alloys that contain silica (EPA Chemical Profile, 1987). From a worker inhalation exposure standpoint, the Occupational Safety and Health Administration (OSHA) has set inhalation limits for hydrofluoric acid at 3 ppm (2.5 mg/m3)(OSHA, 2001). Hydrofluoric acid is used in numerous applications in the semiconductor industry in the form of quartz and metal etching; but along with being very beneficial, it also has numerous disadvantages. From a dermal contact standpoint, hydrofluoric acid eventually causes a very corrosive and unique chemical burn. Upon skin contact, hydrofluoric acid causes tissue destruction by two methods. One, the unstable fluoride ions penetrate tissues and adsorb calcium and magnesium, which can lead to failure of various internal organs. Second, the hydrogen ion causes a deep corrosive burn that is slow-to-heal (American Chemical Society, 1997). Consequently, knowledge of the toxicological effects, as well as treatment methods pertaining to hydrofluoric acid exposure, are vital. From a dermal exposure standpoint, various studies have been preformed on the treatment methodologies for hydrofluoric acid exposure. Upon exposure, treatment must be administered immediately or the threat of death is substantial (Bracken, Cuppage, McLaury, Kirmin, & Klaassen, 1985). Two possible methods of treatment for skin exposure exist. The more commonly used compound is calcium gluconate, with an alternative but less-utilized organic material known as Zephiran (Dunn, MacKinnon, Knowlden, Billmaier, Derelanko, Rusch, Naas, & Dahlgen, 1992). One study indicated that the injection of calcium gluconate can be reasonably effective at neutralizing hydrofluoric acid that has penetrated bodily tissues (Dunn, et al., 1992), the chemical composition of calcium gluconate may not lend itself to topical-oriented treatment methodologies to the extent that Zephiran can.