What is Phosphoric Acid?

Phosphoric acid (chemical formula: H₃PO₄), also known as orthophosphoric acid, is a colourless and odourless inorganic acid. In its purest form, it is found in a solid crystalline state.

What is Phosphoric Acid used for?

Phosphoric acid has a range of uses across various industries. For instance; it is used as an additive to food and drink to give a sharp and tangy flavour, but also as an ingredient in fertilisers, detergents and even dental cements.  

Phosphoric Acid Hazards

The main routes of exposure to phosphoric acid are through skin and eye contact, although exposure can be toxic to multiple body systems; including the integumentary (hair, skin and nails) and respiratory systems. 

As always, the severity of symptoms will depend on the level and type of exposure to occur with permanent harm being a very real possibility.

Skin or eye contact with the chemical can cause; pain, severe burns, blurred vision, blistering and redness.

Inhalation of phosphoric acid can lead to irritation of the nose and throat. 

If ingested, phosphoric acid can cause burning of the throat, stomach, lips and tongue along with other possible symptoms including; diarrhoea, nausea, cramps and vomiting. 

Long term exposure to the acid can result in red, dry, and cracked skin as well as conjunctivitis in the eye. It can also cause decay in your teeth and ulcers in the mouth. 

Phosphoric Acid Safety

While Phosphoric Acid is a common and safe ingredient in food and drink, if ingested in levels of excess, it will be toxic to the human body and vomiting should be not induced. If the person is conscious, they should be given water to rinse their mouth out and a medical professional should be alerted.

In the event of exposure to skin; remove the contaminated clothing, footwear and accessories and cleanse the affected area with plenty of water. Contaminated clothing must be decontaminated prior to wearing again. 

If the acid gets into a person’s eyes, flush them with fresh running water for at least 30 minutes, making sure you do not forget to wash under the eyelids. Contact a medical professional.

If inhalation is the route of exposure, the person affected should be moved to a fresh air source and monitored in case symptoms arise.

Phosphoric Acid Safety Handling

Safety showers and emergency eyewash fountains should be accessible in the immediate area of the potential exposure to the chemical. 

Adequate ventilation should be available when using Phosphoric Acid and local exhaust ventilation should be installed if necessary. 

Personal Protective Equipment (PPE), such as safety glasses with side shields, protective clothing, aprons, gloves and masks are always essential when dealing with acidic chemicals.

Wearing contact lenses should also be avoided around the phosphoric acid as they are able to absorb some of the chemical in the air.

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