Boric Acid is a weakly acidic hydrate of boric oxide with mild antiseptic, antifungal, and antiviral properties. The exact mechanism of action of boric acid is unknown; generally cytotoxic to all cells. It is used in the treatment of yeast infections and cold sores.Boric acid is an odorless white solid. Melting point 171°C. Sinks and mixes with water. (USCG, 1999)Boric acid is a member of boric acids. It has a role as an astringent. It is a conjugate acid of a dihydrogenborate.