Inhibited hydrofluoric acid composition
An inhibited hydrofluoric acid aqueous composition, said composition comprising: hydrofluoric acid in solution; and an alkanolamine; wherein said alkanolamine and hydrofluoric acid are present in a molar ratio of at least 1:1.
1. A method of preparing an inhibited hydrofluoric acid composition, the inhibited hydrofluoric acid composition consisting of an aqueous solution of hydrofluoric acid and one or more alkanolamines, the method comprising:
adding one or more alkanolamines into a solution of hydrofluoric acid until the molar ratio of alkanolamine:hydrofluoric acid is at least 1.1:1,
wherein the prepared inhibited hydrofluoric acid composition has a pH ranging from 11.15 to 12.
2. The method of claim 1 , wherein the one or more alkanolamines is selected from the group consisting of monoethanolamine; diethanolamine; triethanolamine and combinations thereof.
3. The method of claim 1 , wherein the one or more alkanolamines is monoethanolamine.
4. The method of claim 3 , wherein the prepared inhibited hydrofluoric acid composition exhibits an acute dermal toxicity LD50 or greater than 5,050 mg/kg.
5. The method of claim 3 , wherein the prepared inhibited hydrofluoric acid composition is non-corrosive to an intact skin after four hours of exposure to the intact skin.
6. The method of claim 3 , wherein the prepared inhibited hydrofluoric acid composition exhibits a Primary Irritation Index (PII) of 0.4 after four hours of exposure to intact skin based on 1 hour, 24 hour, 48, hour and 72 hour observations of the exposed intact skin.
7. The method of claim 1 , wherein the one or more alkanolamines is diethanolamine.
8. The method of claim 1 , wherein the one or more alkanolamines is triethanolamine.
9. The method of claim 1 , wherein the solution of hydrofluoric acid consists of hydrogen fluoride and water.