Trisodium phosphate is an inorganic compound that is highly soluble in water and is often found as an additive in foods, stain removers, lubricants, and other cleaning agents. While its use in consumer products is accepted and popular, its use in food has increasingly come under question.
What is Trisodium Phosphate?
Bearing the chemical formula Na₃PO₄, trisodium phosphate is an inorganic compound typically found in a white powder or crystalline form. It is commonly used as an all-purpose cleaner since it can be easily mixed with warm water to produce an effective cleaner for grease, mildew, soot, and other hard-to-clean messes. You will also find sodium triphosphate in various foods. It is an alkaline substance and is hence, used to decrease the acidity found in certain food products. 
You will find trisodium phosphate all around you, such as:
- It is a popular cleaning agent. 
- It is found in lubricants, stain removers, and degreasers.
- It is a food additive that may be found in various cereals and other acidic foods. As a phosphorous-derived compound, it is an inorganic form and is typically added to highly processed foods.
- It is also relied on to help certain foods rise, balance the pH level, retain moisture, protect flavor, and improve texture.
Trisodium Phosphate in Cereal
One of the main areas of contention in the debate over this phosphorus compound is its inclusion in breakfast cereals. It is often used as an ingredient in popular breakfast foods, which tend to be highly processed. However, many large companies, such as General Mills, include trisodium phosphate in cereal to reduce the acidity levels and change the color of the cereal. The FDA has noted that this compound is generally safe when consumed orally in small doses. The recommendation is not to consume more than 70 mg per day, and the amount in most cereal is far less than this total. 
That being said, many consumers are concerned about the inclusion of this compound, since it is also found in paint thinners and industrial bleach products. Many organic and independent cereal producers have stopped using this phosphoric compound as a preservative or additive in their products. If you are concerned about its safety, you may want to avoid products that use this additive. 
Trisodium Phosphate in Food
Aside from cereals, you will also find trisodium phosphate in many processed and pre-packaged foods, especially lunchmeat and processed cheese, canned soup, cake mixes, pizza dough, mashed potatoes, bacon, and canned tuna, among others, as noted in this article from Clinical Aspects of Natural and Added Phosphorous in Foods. Most organic brands will not include phosphorous-derived inorganic compounds. So it should be easy to avoid this in your diet if you are careful about the products you buy. It is not only food to consider, however, as this phosphate is also found in certain kinds of toothpaste, mouthwashes, baking soda, cosmetics, and certain pharmaceuticals. 
Why is Trisodium Phosphate Added in Food
In the food contexts outlined above, this compound works to help retain the moisture in meat products during storage and cooking. It also helps cheese keep its shape and melt evenly. In the case of cake mixes and other bread mixtures, it can act as a leavening agent that keeps the food ‘fluffy’. It is sometimes used as a thickening agent in packed foods like mashed potatoes and may prevent color changes in soda. It is included in toothpaste and mouthwash because of its antibacterial effects. Thanks to its heavily alkaline nature, you will also find it as an ingredient to reduce the acidity in foods. Again, as with cereals, the amount of this phosphorous compound that is included in most foods is negligibly small. However, if your diet is high in processed foods, your daily total may exceed the safety recommendation from the FDA. 
When consumed in large quantities, such as those found in cleaning products, trisodium phosphate is very dangerous.
- It is linked to higher calcium deposition in the body, kidney stones, cancer, and even death. For those with kidney disease, eating an excessive amount of foods with this phosphate compound can be very dangerous, as shown in this study from Trends in Food Science and Technology. 
- It can irritate the stomach lining and the intestinal walls, and reduce the levels of lactic acid in the muscles. This compound was regularly found in dishwashing liquids and laundry detergents until 2011 when it was found to be damaging to the environment. The CDC lists this compound as a hazardous substance that could result in abdominal pain, shock, or collapse. 
The amount you will need to experience such serious side effects is far more than what is found in regular food. However, many people object to its presence in food of any kind. There are numerous ongoing research studies exploring the potential negative effects of trisodium phosphate. But at present, it is still legally allowed and included in many popular consumer food items in the United States and elsewhere.