Phosphoric acid is colorless, odorless and has many uses in our food supply — it actually might be listed as an ingredient on the label of one of your favorite snacks or drinks.
Phosphoric acid can be used to leaven baked goods, add a sharp flavor to beverages, increase the shelflife of sweet drinks and food or maintain the structure and hydration of processed meat and seafood, according to an August 2017 review in Comprehensive Reviews in Food Science and Food Safety.
Video of the Day
It's also included in fertilizers, bonding agents, soaps and detergents and used to make rust-proof paint among many other uses, according to the Australian Government's National Pollutant Inventory.
On a food's ingredient list, you might see several types of phosphates listed in combination with other minerals. Phosphoric acid is just one form of phosphorus, an essential mineral that helps make up our bones, teeth and DNA, per the National Institutes of Health (NIH). Phosphorus is naturally found in many foods, including dairy, meat, seafood, some nuts, fruits, vegetables and grains.
The U.S. Food and Drug Administration (FDA) lists phosphoric acid as generally recognized as safe (GRAS). By itself, phosphoric acid is safe, but eating an excess amount of processed foods that contain phosphate additives can lead to getting too much phosphorus, which can be dangerous for your health.
What Are the Side Effects of Phosphoric Acid?
Eating too much phosphate, which is found naturally in food and in processed foods as phosphoric acid or as phosphate salts, can cause problems with your heart, kidneys or bones, according to the NIH. The recommended upper limit for phosphorus is 4,000 milligrams per day for adults.
Below, find the top foods high in phosphoric acid. People with chronic kidney disease should limit their intake of these foods because studies have shown that high phosphate levels are linked to an increased risk of mortality or disease progression, per the NIH.
1. Soft Drinks
Coke, Pepsi and many other dark soft drinks use phosphoric acid for their sharp flavor and to extend shelf life. Clear soda usually uses citric acid for a similar taste and skips the phosphorus, so it's a better choice for people looking to limit how much phosphorus they eat or drink.
Cola contains 55 milligrams of phosphorus in the form of phosphoric acid. Unlike other phosphate salts or organic phosphorus, your body is able to absorb 100 percent of phosphoric acid, per an October 2017 report in Current Osteoporosis Reports.
While most health organizations recommend avoiding soft drinks to limit added sugars, even diet soda has health concerns, especially when it comes to your teeth. Even though diet soft drinks (like Coke Zero) are sugar-free, they still contain phosphoric acid and are acidic.
The acidity and sugar from soft drinks create an acid attack on your teeth, which can last 20 minutes after every sip, per the Mississippi State Department of Health.
2. Protein Drinks
While milk naturally contains phosphorus, phosphoric acid is often added to milk or juice-based drinks that use whey for added protein.
Because phosphoric acid is a strong acid, it's commonly used to change the pH of a beverage using whey, which is a strong base, per the United States Dairy Export Council.
3. Baking Powder
A baked good recipe usually calls for baking soda or baking powder in order to leaven the final product. Baking powder is the combination of baking soda and two different acids, one of which is a salt of phosphoric acid.
When the phosphoric acid salt is combined with water, it begins the leavening process, according to North Carolina State University. The second acid adds additional leavening once the product is heated, making baking powder a "double-acting" leavening agent.
Coffee has many different acids including acetic, formic, malic, lactic, quinic, chlorogenic and phosphoric acid, per a June 2019 article in Scientific Reports. Acid types and levels depend on a number of factors, including the type of coffee.
After looking at 10 different varieties of Arabica and Robusta coffees, researchers found that Arabica beans contained less phosphoric acid than Robusta beans, per an October 2017 study in the Journal of Environmental Science, Toxicology and Food Technology.
5. Processed Meat
Phosphoric acid and its salts are added to processed meat for a few different reasons: Phosphoric acid acts as a stabilizer and an antioxidant to help maintain texture and limit spoiling, according to a June 2021 article in Foods.
Phosphoric acid and phosphate salts are often added to lunch meat, sausage, bacon and other processed meats.
6. Dairy Products
Various cheeses, cream-based dressings and other dairy products often have phosphoric acid or another acid added to them. Adding an acid to dairy products helps with coagulation.
Using phosphoric acid results in a firmer, harder cheese than other types of acid, per a March 2015 study in the Journal of Food Science and Technology.
- Comprehensive Reviews in Food Science and Food Safety: "Dietary Food-Additive Phosphate and Human Health Outcomes"
- National Pollutant Inventory: "Phosphoric acid"
- NIH: "Phosphorus"
- Current Osteoporosis Reports: "Effects of Excessive Dietary Phosphorus Intake on Bone Health"
- Mississippi State Department of Health: "Soft Drinks and Oral Health"
- United States Dairy Export Council: "U.S. WHEY PROTEINS IN READY-TO-DRINK BEVERAGES"
- Journal of Food Science and Technology: "Effect of acidulants on the recovery of milk constituents and quality of Mozzarella processed cheese"
- North Carolina State University: "The Difference Between Baking Soda and Baking Powder"
- Scienfitic Reports: "Effect of grinding, extraction time and type of coffee on the physicochemical and flavour characteristics of cold brew coffee"
- Foods: "Clean Label Alternatives in Meat Products"
- Journal of Environmental Science, Toxicology and Food Technology: "Analysis Of The Diversity Of Some Arabica And Robusta Coffee From Kenya And Uganda By Sensory And Biochemical Components And Their Correlation To Taste"
- FDA: "CFR - Code of Federal Regulations Title 21"