HYDROFLUORIC ACID

Hydrofluoric acid ( HF) is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine ( Prozac) and diverse materials such as PTFE ( Teflon) . Hydrofluoric acid is a highly corrosive acid, capable of dissolving many materials, especially oxides. Its ability to dissolve glass has been known since the 17th century, even before hydrofluoric acid had been prepared in large quantities by Carl Wilhelm Scheele in 1771.[ 2] Because of its high reactivity toward glass and moderate reactivity toward many metals, hydrofluoric acid is usually stored in plastic containers ( although PTFE is slightly permeable to it) .[ 3] Hydrogen fluoride gas is a severe poison that may immediately and permanently damage lungs and the corneas of the eyes. Water solutions ( hydrofluoric acid) are a contact-poison with the potential for deep, initially painless burns and ensuing tissue death. By interfering with body calcium metabolism, the concentrated acid may also cause systemic toxicity and eventual cardiac arrest and fatality, after contact with as little as 160 cm2 ( 25 square inches) of skin.