Short Historical Background
Nitric acid is a highly corrosive and toxic strong acid and its other terms include aqua fortis and spirit of nitre. The acid was first described as obtained by calcining or heating to a high temperature a mixture of nitre, alum, and blue vitriol. In the 13th century, it was again described by Albert le Grand and Raimon Lull, who prepared it by heating nitre and clay. They then called it “eau forte”. However, its real nature was determined only until the 18th century. It was in 1776 when A.L. Lavoisier showed that it contained oxygen and it was in 1785 when its constitution was determined and that it could be synthesized by passing a stream of electric sparks through moist air. This was courtesy of H. Cavendish.
At high concentrations, it can be a colorless to light yellow fuming liquid. But in lower concentrations, it is a particularly colorless liquid. It is miscible with water, and it reacts with alkalis, basic oxides, and carbonates, thus forming salts, just like ammonium nitrate. It is also has a strong oxider, hence, it should be kept away from organic materials.
Nitric acid has a variety of uses. One of its industrial uses is that it is one of the few reagents capable of dissolving gold and platinum. In woodworking, it is a material used to artificially age pine and maple. Its effect is that it produces a grey-gold color which is similar to very old wax or oil finished wood. It is also commonly used in fertilizer preparation just like ammonium nitrate as well as the preparation of explosives just like nitroglycerin and trinitrotoluene (TNT). Likewise, it is used in the manufacture of chemicals such as in making dyes, ore flotation, photoengraving, etching steel, and reprocessing of spent nuclear fuel. flotation chemicals
Implications on Health and Safety
As mentioned, nitric acid is a toxic and strong substance. Besides its effects on health when not used properly, it can be also a cause of fire.
Inhalation of the vapors of the substance can cause difficulties in breathing and this can lead to pneumonia as well as pulmonary edema. Irritation of the nose and respiratory tract, coughing, and choking are the other symptoms that a person who has inhaled the vapors of the substance may experience. When it comes in contact with the skin, it can cause pain, redness, and severe skin burns. Moreover, concentrated solutions can stain skin with a yellow or yellow-brown color and they can also lead to deep ulcers. Eye contact, on the other hand, can cause severe burns and even permanent damage to the eyes. While long-term exposures to the substance does not take place often because of its corrosive characteristic, cases of long-term of exposure may lead to teeth erosion and lung damage.
First Aid Measures
There are times when accidents just happen, so our knowledge on what to do during those times is very important. In cases of ingestion, never ever induce vomiting. Instead, give the victim large quantities of water or if available, milk. However, if the victim is unconscious then do not give them anything through their mouth. More importantly, immediately seek medical help. In cases of inhalation, on the other hand, remove the victim to a place with fresh air. Give artificial respiration, if not breathing. If breathing is difficult for the victim, give oxygen.
When skin contact takes place, quickly flush the skin with lots of water for at least 15 minutes; do this while removing the victim’s contaminated clothing. If it is eye contact, on the other hand, flush the contaminated eyes with plenty of water for at least 15 minutes, and occasionally lift the lower and upper eyelids.