Nitric acid (chemical formula: HNO₃), is a colourless to slightly yellow liquid, that darkens with age and exposure to light. It has a sharp, strong odour and is highly corrosive to most metals. Adding water to acid causes the substance to generate intense heat, boiling, spattering and steam.
Nitric acid is used in the manufacture of organic and inorganic nitrates/nitro compounds for fertilisers, dye intermediates and several other organic compounds.
Other applications include:
The routes of exposure for nitric acid include; inhalation, ingestion and skin and eye contact.
Inhalation of nitric acid may produce irritation and inflammation of the respiratory system. Inhalation of nitric acid fumes can cause coughing, choking, dizziness, headache, chest pain, gagging, nausea and weakness. In cases of severe exposure, pulmonary oedema (excess fluid in the lungs) can occur—this can be lethal.
Ingestion of nitric acid can cause burns to the mouth, throat and oesophagus, causing immediate pain and difficulty in speaking and swallowing. Other symptoms include nausea, vomiting, diarrhoea, hypotension, weak/rapid pulse circulatory collapse, renal failure and clammy skin. Death is possible, likely resulting from asphyxia, circulatory collapse, aspiration and pneumonia to name a few.
Skin contact with nitric acid may lead to deep burns that are slow to heal. Symptoms to exposure may be delayed, appearing hours after the event. Entry into the bloodstream through open cuts or wounds may produce other harmful effects.
Animal experiments suggest nitric acid produces severe ocular lesions that last over 24 hours after the exposure. Symptoms include pain, burns and possible permanent damage. Mild burns generally recover quickly and fully, however severe burns can produce lasting and possibly irreversible damage (i.e. blindness).
If inhaled, remove the patient from the contaminated area to the nearest fresh air source. Lay them down and ensure they are warm and rested. If the patient is not breathing and you are qualified to do so, perform CPR (preferably with a bag-valve mask device). Seek medical attention without delay.
If swallowed, urgent hospital treatment is likely to be required. Do not induce vomiting, however if vomiting does occur, lean the patient forward or place them on their left side to maintain open airways and prevent aspiration. Give them water to rinse their mouth out and provide as much as they can comfortably drink. Seek medical attention without delay.
If skin exposure occurs, immediately remove all contaminated clothing, footwear and accessories and flush the affected area with plenty of water. Seek medical attention.
If the chemical is exposed to the eyes, flush the eyes out immediately with fresh running water for at least 15 minutes, remembering to wash under the eyelids. Removal of contact lenses should only be done by a skilled individual. Seek medical attention without delay.
Emergency eyewash fountains and safety showers should be accessible in the immediate area of the potential exposure to the chemical and adequate ventilation should be available (install local exhaust if necessary).
The PPE recommended when handling nitric acid includes; safety glasses with unperforated side shields, chemical goggles, full face shields or gas masks, elbow length PVC gloves, overalls, PVC aprons, PVC protectives suits (in cases of severe exposure) and safety boots.
Improper handling of nitric acid can be a very hazardous activity. Always read a copy of the SDS before handling hazardous chemicals. Click here for a trial of our SDS Management Software or contact us at firstname.lastname@example.org for more information about our chemicals management solutions.
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