Nitric Acid: Uses, Dangers, Precautions

Nitric acid, with the chemical formula HNO3, is one of the most important acids that does not come from organic matter. It is found in medications in its salt form called nitrate and as a salt of nitric acid. Nitric acid is very dangerous to health and must be handled with care.

Definition: what is nitric acid?

Nitric acid, with the chemical formula HNO3, is one of the most important acids that do not come from organic matter. Is he star component of fertilizers, and is one of the most manufactured chemical materials in the world. It is found in nature in the form of salts called nitrates, but today its chemical synthesis is the most widespread. It is a strong acid and a powerful oxidizer capable of attacking almost all metals, except gold in particular. It is also because of this ability to separate gold from other metals by dissolving them that it was previously called “strong water” (or “aqua fortis”). When coupled with cyanides, carbides or metallic powders, the reactions obtained can be explosive. Nitric acid is a liquid with a characteristic pungent odor and is colorless when pure, but turns yellowish-brown on contact with impurities. It also releases red or yellow fumes at room temperature. It is found in the form of more or less concentrated aqueous solutions, generally varying from 52% to 68% nitric acid for professional use, much less (usually less than 5%) for general public domestic use.

What medicines contain nitric acid?

Nitric acid as such is not is not on drugs and has no medical interest special. Is only in its salt form called nitrate which is used in pharmacy. Nitrate-based drugs include mainly treatment antifungal allowing treat fungal infections, such as econazole nitrate (Fongilein®, Mycoapaisyl®, Pevisone®, Mycosedermyl®, Pevaryl® and Gynopevaryl® as well as its generics Dermazol®, Gynopura®, Myleugyne®, Univagil® and econazole), miconazole, d’isoconazole (Fazol®), fenticonazole (Terlomexin®, Lomexin® and others
generic fenticonazole), omoconazole (Fongamil®), oxiconazole (Fonx®), or sertaconazole (Monazole® and its generic Candazol®). Also, other drugs consist of an active ingredient as nitric acid salt as in oligotherapy with Silver Granions® (silver nitrate) or Bismuth (bismuth nitrate), in homeopathy with Boiron® sempervirine nitrate, as well as naphazoline nitrate (Collyre Bleu Laiter®, Derinox®) or even pilocarpine nitrate (Pilocarpine Faure® eye drops). Finally, the reaction of glycerin with nitric acid gives nitroglycerin, also known as trinitrin, which is the active ingredient in the following drugs used in cardiology: Discotrine®, Epinitril®, Natispray®, Nitriderm®, Nitronal®, Trinipatch® , trinitrin Mylan® and Rectogesic® (used against chronic anal fissures),

What are the uses of nitric acid?

The main use of nitric acid is in the manufacture of fertilizers, in the form of ammonium nitrate (obtained by reaction between nitric acid and ammonia). Ammonium nitrate is the most common component of mineral fertilizers in the world. In addition, 75% of the production of nitric acid is destined to the manufacture of nitrogenous fertilizers. Nitric acid is also used. in horticulture to acidify the soil. On its own, it is capable of reacting with most metals (except gold, iridium, and platinum), which is why it is used in the fields of microelectronics and metallurgy. On the contrary, the mixture of nitric acid andhydrochloric acid forms aqua regia, a solution for dissolving noble metals such as gold or platinum. In combination with certain compounds (eg aromatic compounds), it is involved in the production of explosives or rocket fuel. Nitric acid can also be exploited in the production of plastic or synthetic fibers such as nylon. On a smaller scale, nitric acid can be used to produce stains, varnishes or lacquers, the cleaning of metallic surfaces, the refining of precious metals in the field of jewellery, the artificial dyeing of wood (aged appearance) or even domestic uses (cleaning products). Nitric acid is also used in skin surgery (use reserved for a health professional) to treat warts or calluses.

What is the mode of action of nitric acid?

Nitric acid reacts by oxidation with other components, such as organic compounds, minerals or metals, this being due to the nitrate ion NO3-. The reactions thus obtained can be explosive, with possible generation of flames. Metals dissolve with nitric acid. Since nitric acid is a strong acid, it also reacts very violently with strong bases. In dermatological surgery, it causes a Burn Type of third degree burn, which destroys the wart.

What are the dangers of nitric acid?

Nitric acid is very dangerous to health and must be handled with care. Can be mortal according to the intensity of intoxication. In gaseous form (nitrous vapors obtained by thermal decomposition of nitric acid or by reaction with other compounds), it is very corrosive and irritating and can lead to suffocation. Illinois attacks the respiratory tract which can cause runny nose, cough, pain, labored breathing, or even pulmonary edema or even pneumonia. It can also be seen eye irritation (tears, sensitivity to light, blurred vision, pain, redness, etc.). Inhalation of this acid can give late symptoms over time. In liquid form, nitric acid is very corrosive and can cause damage both by splashes on the skin and in the eyes (burns, necrosis, various eye injuries that can cause loss of sight) only if swallowed. The consequences of ingestion will depend on the amount of product ingested and the degree of acidity of the product (depending on the pH > or < 1.5). The signs can be:

  • pain in the digestive tract,
  • vomiting,
  • digestive bleeding,
  • ulcerations,
  • perforations of the esophagus or stomach (which can cause death),
  • digestive stenosis,
  • metabolic acidosis,
  • disseminated intravascular coagulation,
  • an increase in white blood cells,
  • oral lesions (of the tongue, ulcerations, necrosis),
  • difficulty speaking or eating
  • hypersalivation,
  • a respiratory distress,
  • anxiety,
  • concern,
  • tachycardia or a state of shock or even death.

In case of contact with organic materials such as sawdust, paper or rags and certain solvents, it can cause ignition. Due to its strong reaction with reducing agents or combustible materials, explosions may occur.

What happens if you inhale or ingest nitric acid?

If nitric acid is inhaled, it is essential remove the victim from the exposure area, d’ventilate the premises and then remove any clothing that may be contaminated. The victim must be resting, half sitting if you have difficulty breathing or side safety position if you are unconscious. Necessary immediately contact the toxicology center and/or SAMU depending on the severity of the symptoms. It will then be necessary to schedule a medical appointment to check the general condition and the lungs, as well as an ophthalmological consultation. If nitric acid is ingested, do not make the victim drink or vomit, as this could aggravate symptoms by re-forming the product in the upper digestive tract or increasing its absorption by the body. It is advisable to immediately call the poison control center that will indicate the actions to take in the situation and according to the symptoms. In case of life-threatening emergency or serious disorders, call SAMU. The consequences of an ingestion can be potentially serious or even fatal, so it will be necessary to plan a complete medical examination, which may sometimes require hospitalization.

What to do if you have nitric acid on the skin?

If nitric acid comes into contact with the skin, immediately wash the affected area with plenty of clean water, carefully removing contaminated clothing if applicable. It may be advisable to put on gloves before handling impregnated clothing. As a precaution in case of small splashes, it is recommended to wash the whole body (as well as the scalp and face) with water. Washing should last at least 15 minutes, and it is advisable not to place the affected skin directly under the stream of water, but at a distance of about 15 cm (this is in the case of sensitive skin lesions and in order not to aggravate an injury with the force of the jet). Diphoterine® solution is an emergency rinse solution that is sprayed Chemical products that stops the reaction of the product with tissues such as the skin or the eyes. It can be used in case of skin contact with nitric acid, its use as soon as possible will limit injuries. On the other hand, it is important not to neutralize the nitric acid with a base, at the risk of causing a chemical reaction that could aggravate the burn. After washing with water (or Diphoterine®), it will sometimes be necessary to apply a sterile dressing with tulle gras, and after careful disinfection of the damaged skin. Nitric acid can stain the skin yellow by reaction with the epidermis (xanthoderma).

What precautions should be taken when handling nitric acid?

Since nitric acid is capable of causing explosive reactions, combustion and serious health risks, special storage and handling precautions are necessary. It must be stored and transported in suitable and resistant tanks or containers, protected from direct light and at a temperature below 20 degrees. Care must be taken that there are no metals or flammable substances nearby. It should be placed in a well-ventilated room. Its handling requires the use of equipment such as protective glasses, respirator, clothing and gloves resistant to nitric acid (not latex or nitrile, flammable materials in contact with nitric acid). It is recommended to wash your hands and face after handling nitric acid. Nitric acid products must be kept out of the reach of children.

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