The primary industrial use of boric acid is in the manufacture of monofilament fiberglass usually referred to as textile fiberglass. Textile fiberglass is used to reinforce plastics in applications that range from boats, to industrial piping to computer circuit boards.
In the jewelry industry, boric acid is often used in combination with denatured alcohol to reduce surface oxidation and firescale from forming on metals during annealing and soldering operations.Boric acid is used in the production of the glass in LCD flat panel displays.
In electroplating, boric acid is used as part of some proprietary formulas. One such known formula calls for about a 1 to 10 ratio of H3BO3 to NiSO4, a very small portion of sodium lauryl sulfate and a small portion of H2SO4.
Boric acid, mixed with borax (sodium tetraborate decahydrate) at the weight ratio of 4:5, is highly soluble in water, though they are not so soluble separately. The solution is used for fire retarding agent of wood by impregnation.It is also used in the manufacturing of ramming mass, a fine silica-containing powder used for producing induction furnace linings and ceramics.
Boric acid is one of the most commonly used substances that can neutralize active hydrofluoric acid (HF). It works by forcing the free anions into complex salts. This process defeats the extreme toxicity of hydrofluoric acid, particularly its ability to sequester ionic calcium from blood serum which can lead to cardiac arrest and bone decomposition; such an event can occur from just minor skin contact with HF.Boric acid is added to borax for use as welding flux by blacksmiths.Boric acid, in combination with silicone oil, is used to manufacture Silly Putty.Boric acid may be used in Marcellus Shale hydraulic fracturing in Pennsylvania.
Boric acid can be used as an antiseptic for minor burns or cuts and is sometimes used in salves and dressings, such as boracic lint. Boric acid is applied in a very dilute solution as an eye wash. Dilute boric acid can be used as a vaginal douche to treat bacterial vaginosis due to excessive alkalinity, as well as candidiasis due to non-albicans candida. As an antibacterial compound, boric acid can also be used as an acne treatment. It is also used as prevention of athlete's foot, by inserting powder in the socks or stockings, and in alcohol solution can be used to treat some kinds of otitis externa (ear infection) in both humans and animals. The preservative in urine sample bottles in the UK is boric acid.
Boric acid solutions used as an eye wash or on abraded skin are known to be toxic, particularly to infants, especially after repeated use; this is because of its slow elimination rate.