Boric Acid B(OH)3
Aka CAS No. 10043-35-3 , trihydroxidoboron, Hydrogen Borate, boracic acid, orthoboric acid, acidum boricum, Sassolite, Optibor, Borofax
Boric acid, also called boracic acid, orthoboric acid or acidum boricum is a weak acid of boron often used as an antiseptic, insecticide or flame retardant,. Boric Acid is also used in nuclear power plants to control the fission rate of uranium. It exists in the form of colorless crystals or a white powder and it dissolves in water. The chemical formula for boric acid is H3BO3, sometimes written B(OH)3. When occurring as a mineral, it is called sassolite.
Free boric acid is found in certain volcanic districts such as Tuscany, the Lipari Islands and Nevada. It is also found as a constituent of many minerals such as borax, boracite, boronatrocaicite and colemanite. The presence of boric acid and its salts have also been identified in seawater. It also exists naturally in many plants and almost all fruits.
Boric acid was first prepared by Wilhelm Homberg (1652-1715) from borax by the action of mineral acids. However Borates, including boric acid, have been used since the time of the Greeks for cleaning, preserving food, and other activities. Boric acid may be prepared by reacting borax (sodium tetraborate decahydrate) with a mineral acid such as hydrochloric acid.
Boric acid can be used as an antiseptic for minor burns or cuts and is sometimes used in dressings or salves or is applied in a diluted solution as an eye wash.
As an anti-bacterial compound, boric acid can also be used as an acne treatment. Boric acid can be used to treat yeast and fungal infections such as vaginal yeast infections. It is also used as prevention of athlete's foot by inserting powder in the socks or stockings. In solutions, boric acid can be used to treat some kinds of ear infections in both humans and animals. The preservative in urine sample bottles in the UK is boric acid.
Boric acid was first registered in the US as an insecticide in 1948 for the control of cockroaches, termites, fire ants, fleas, silverfish, and many other insects. The product is generally considered to be safe to use in household kitchens to control cockroaches and ants. It acts as a stomach poison affecting the insects' metabolism, and the dry powder is abrasive to the insects' exoskeleton. Boric acid can also be made into a paste or gel form as a powerful and effective insecticide much safer to humans than many other insecticides. The paste or gel has attractants in it to attract insects. The boric acid slowly causes dehydration.
In combination with its use as an insecticide, boric acid also prevents and destroys existing wet and dry rot in timbers. It can be used in combination with an ethylene glycol carrier to treat external wood against fungal and insect attack. It is possible to buy borate-impregnated rods for insertion into wood via drill holes where dampness and moisture is known to collect and sit. It is available in a gel form and injectable paste form for treating rot affected wood without the need to replace the timber. Concentrates of borate-based treatments can be used to prevent slime, mycelium and algae growth, even in marine environments.
Boric acid is added to salt in the curing of cattle hides, calfskins and sheepskins. This helps to control bacteria development and helps to control insects.
Boric acid is used in nuclear power plants as a neutron poison to slow down the rate at which fission occurs. Fission chain reactions are generally driven by the amount of neutrons present. Natural boron is 20% boron-10 and about 80% boron-11. Boron-10 has a high cross-section for absorption of low energy (thermal) neutrons. By adding more boric acid to the reactor coolant which circulates through the reactor, the probability that a neutron can survive to cause fission is reduced. Therefore, changes in boric acid concentration effectively regulate the rate of fission taking place in the reactor. This method is only used in pressurized water reactors (PWRs). Boron is also dissolved into the spent fuel pools containing used uranium rods. The concentration is high enough to keep neutron multiplication at a minimum.
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.[19]
In the jewelry industry, boric acid is often used in combination with denatured alcohol to reduce surface oxidation and fire scale 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.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 F- anions into complex salts This process removes the virulence of hydrofluoric acid, particularly its ability to attack calcium in human bone (greatly reducing its strength); 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 and farriers. Boric acid, in combination with silicone oil, is used to manufacture Silly Putty.
It is also used in pyrotechnics to prevent the amide-forming reaction between aluminum and nitrates. A small amount of boric acid is added to the composition to neutralize alkaline amides that can react with the aluminum. Boric acid can be used as a colorant to make fire green. For example, when dissolved in methanol it is popularly used among fire jugglers and fire spinners to create a deep green flame.
