What is Sodium Hexametaphosphate E452i? Uses, Safe, Benefit, Side effects

What is Sodium Hexametaphosphate E452i? Uses, Safe, Benefit, Side effects


Table of Contents

Sodium hexametaphosphate is a mixture of sodium metaphosphate and sodium tripolyphosphate. It’s mainly used as a preservative, a dry cleaning agent, and a wetting agent in the petrochemical industry. It can also be used as an emulsifying agent, or as a component of detergents, fertilizers, and other non-constituent additives. As a food additive, it has the number E452i in the European Union.

What is sodium hexametaphosphate?


Sodium hexametaphosphate is a salt consisting of sodium ions and six phosphate ions. It is used as a food additive and as a laundry booster.

Sodium hexametaphosphate can be prepared by heating sodium chloride with phosphoric acid. It is often sold as a solid powder or flakes, which dissolve in water to give an alkaline solution containing the disodium salt of hexametaphosphoric acid: NaPO(OH)·6HO.

It is used as an emulsifier, thickener, stabilizer, and anticaking agent in foods such as ice creams, cereals, baked goods, canned tuna fish, and other canned seafood products.

What is sodium hexametaphosphate used for?


Sodium hexametaphosphate is a chemical compound that is used as a food additive and a detergent builder. Sodium hexametaphosphate is also used in the textile industry as an emulsifying agent and dispersing agent.

Sodium hexametaphosphate acts as a water softener by binding with calcium and magnesium ions in the water, making them unavailable to form insoluble calcium carbonate scale. This makes it ideal for use in dishwashing liquids, laundry detergents and automatic dishwasher detergents.

Sodium hexametaphosphate can also be used in cosmetic formulations as an antistatic agent. It is also used in toothpastes for its ability to help disperse particles in the formula.

What is sodium hexametaphosphate made of?


Sodium hexametaphosphate is a chemical compound that is used in many industries, including the food industry. It is also known as sodium trimetaphosphate and STMP.

It is made by reacting sodium hydroxide with phosphoric acid to produce sodium hexametaphosphate. The chemical formula for SHMP is NaPO(PO)6. It has been shown to be an effective antimicrobial agent against the growth of E.coli and Salmonella on surfaces that have been cleaned with it

The main component of sodium hexametaphosphate is sodium phosphate. It also contains one or more salts of phosphoric acid. Most STMPs contain two phosphates and two acids, though some may have three phosphates and one acid, or four phosphates and one acid. The salts that are found in STMP include calcium hydrogen phosphate, potassium hydrogen phosphate, ammonium phosphate, sodium dihydrogen phosphate, calcium dihydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate.

How is sodium hexametaphosphate made?


Chemical synthesis can produce SHMP, an inorganic polyphosphate. The following are three manufacturing processes based on different raw materials:

1. Sodium chloride and phosphoric acid


Sodium chloride and phosphoric acid are used as raw materials in melt polymerization.

2. Caustic soda and phosphoric acid


An agglomeration gasifier will agglomerate phosphoric acid and caustic soda liquid, after which sodium nitrate will be added. Then dewatering and agglomerating processes will be conducted.

3. Monosodium orthophosphate


The sodium acid pyrophosphate is generated by heating monosodium orthophosphate. The reaction equation is as follows:

  1. 2 NaH2PO4 → Na2H2P2O7 + H2O
  2. 3 Na2H2P2O7 → (NaPO3)6 + 3 H2O



Other Names


It is commonly known as Calgon S, Graham’s salt,Sodium metaphosphate , glassy, Sodium polyphosphates,  Sodium tetrapolyphosphate, Sodium polymetaphosphate, and Hexasodium metaphosphate.

CAS Number



Chemical formula


Metaphosphates with four or more phosphate units are referred to as sodium metaphosphates. (NaPO3)6 is the chemical formula of SHMP, which has six phosphate units.

Molecular weight








Platelets, granules, or powders, it is colourless or white.


Easily hydrolyzed to orthophosphate in warm water, acidic or alkaline solutions due to its glassy texture and strong absorption ability.



P2O5 content correlates directly with pH, with higher pH accompanying lower P2O5 content.


Water-soluble, organic solvent-insoluble

What is the application of sodium hexametaphosphate?

Besides being used in food and beverage production, SHMP can also be used in the production of personal care products, as well as in water treatment. It can be found on the market in glassy, granular, or powdered forms. In the market,it exists in technical grade and food grade.


In general, it is a multi-functional ingredient that works as a PH regulator, chelating agent for metal ions, bulking agent, binder, etc.

By increasing starch molecular weight and stabilizing the structure of starch, food-grade SHMP produces modified food starch.

Fish, shellfish, and other aquatic products are often processed with sodium phosphate as a water-retaining agent as well as a quality or taste enhancer. The salt is also used in processing cheese as an emulsifier.

Here are two of its most common uses in food.


A variety of beverages contain SHMP. Aside from extending shelf life, enhancing flavor, improving clarity, and preventing turbidity, it is often used in fruit juices and carbonated beverages, among others. Protein drinks can benefit from it as well because it stabilizes the protein and enhances the flavor

Canned food

The colors of canned beans, fruits, and vegetables are protected by SHMP because it stabilizes natural pigments. Additionally, it maintains a uniform texture by emulsifying fat in canned meat.

Furthermore, food-grade SHMP can be combined with other sodium phosphates to enhance flavor, keep the meat moist, and extend shelf life in meat, cheese, seafood, dairy products, and poultry.


Cosmetic and personal care products contain SHMP as an anticorrosive, masking agent, and chelating, according to the European Commission’s database.

Below are some examples of personal care products with SHMP:

  • Calcium deposits on teeth are removed by toothpaste and mouthwashes.
  • Water softening and pH adjusting bath salts.

Water treatment

Water treatment uses SHMP as a sequestrant in the technical grade. Lead and copper leaching, as well as biofilm formation, can be reduced by using it on pipes and other equipment. Moreover, it can chelate metal oxides such as magnesium and calcium.


Furthermore, it can be used in a variety of other industrial applications in the processing of clay (as a deflocculant), as a cleaning agent, and as drilling fluids.

Is sodium hexametaphosphate safe?

Certainly, FDA, EFSA, and WHO’s Joint FAO/WHO Expert Committee on Food Additives have approved its safety when used as an ingredient in the food.


In fruit jellies, frozen desserts, chess, and food dressings, SHMP can be used as a flavoring agent or adjuvant. When used as a sequestrant according to good manufacturing practices, In general, it is considered safe (GRAS).


A subclass of polyphosphates (E452), SHMP (E 452i) is classified as an “additive other than colors and sweeteners”. According to Annex II of Regulation (EC) No 1333/2008 on food additives, it has been approved as a food additive in the European Union (EU). Specific purity criteria have been defined in Regulation (EU) No 231/2012 of the Commission.

Safety re-evaluation in 2019

According to EFSA, phosphates expressed as phosphorus should be consumed at a level of 40 mg/kg body weight per day to be safe for humans.


Foods may contain it at a maximum level of 10,000 mg/l or mg/kg, and the following foods may contain it:

  • Analogs and dairy products
  • Oils and fats and emulsions of oils and fats
  • Edible ices
  • Vegetables and fruits
  • Confectionery
  • Cereals and cereal products
  • Bakery wares
  • Meat
  • Fish and fisheries products
  • Eggs and egg products
  • Sweeteners such as sugar, syrups, honey, and tabletop products
  • Spices, salts, salads, sauces, soups, and protein products
  • Beverages
  • Ready-to-eat savories and snacks
  • Desserts
  • Infants and young children are excluded from food supplements

Food Standards Australia New Zealand

The code number 452 for this ingredient is “Sodium polyphosphates, glassy” in Australia and New Zealand.


Functional class: Food additives: thickener, texturizer, sequestrant, emulsifier.

What are the sodium hexametaphosphate benefits?

Sodium hexametaphosphate is a compound that is added to food products to improve their texture, consistency, and shelf life. This additive has been used for decades and is approved by the Food and Drug Administration (FDA).

Sodium hexametaphosphate has many other uses. For example, it is used in the production of pesticides, processed foods, and pharmaceuticals. It can also be found in some toothpaste and mouthwashes because it has been shown to help prevent cavities by reducing the plaque on teeth.

The sodium hexametaphosphate benefits include:

Helps remove calcium deposits from pipes in water systems;

It May be used as an antifoaming agent in industrial processes;

Can be used as a thickening agent in paints and adhesives;

Can help prevent corrosion by reducing water activity in concrete;

Can act as a food preservative by inhibiting the growth of microorganisms;

Can be used in the production of detergents and shampoos;

May help reduce tooth decay by preventing plaque from attaching to teeth;

What are the sodium hexametaphosphate side effects?

Sodium hexametaphosphate is a common food coloring used in the food industry. This compound is used to color chicken and steak. The consumption of this compound can result in skin irritation on the part of those consuming the food. Moreover, it has also been known to cause cancer in rats, mice, and rabbits.

SHMP caused several side effects in chronic studies in animals, according to a report published in the International Journal Of Toxicology in 2001. :

  • Inhibition of growth increase in kidney weight
  • Decalcification of the bones
  • Hyperplasia and hypertrophy of the parathyroid gland
  • Anemia of organic phosphates
  • The size of muscle fibers in the liver is altered, along with focal necrosis

Where to buy sodium hexametaphosphate?

You can buy sodium hexametaphosphate from Amazon. You will find the best prices for this product on Amazon, as it is a very popular brand. It is also available at Walmart, Home Depot and Lowe’s.

Hexamine can be purchased on eBay as well as other online retail stores such as Grainger Industrial Supply Company (GISCO), Ace Hardware, Northern Tool, and more.

If you are interested in buying large quantities from China, Grade Chemical is your best choice, contact us directly: info@gradechemical.com

Frequently asked questions

Is sodium hexametaphosphate toxic?

According to EFSA, phosphates (including SHMP) are not carcinogenic or genotoxic in human exposure and are of low acute oral toxicity. Developmental toxicity studies did not reveal any effects.

Is sodium hexametaphosphate safe for pregnant?

In general, it is safe, but you should consult your doctor before taking it.

Is sodium hexametaphosphate safe?

Sodium hexametaphosphate is considered safe by the United States Food and Drug Administration and Canadian Center for Biologics Evaluation and Research. It is also approved for use in Europe, Australia, New Zealand, South Africa, China, Japan and other countries around the world.

Sodium hexametaphosphate is used as a food additive to enhance some foods’ flavors and textures. It’s also used in toothpaste as an abrasive agent to clean teeth. While sodium hexametaphosphate has been linked to asthma in some people with a sensitivity to it, there’s no evidence that this reaction is caused by the phosphates themselves.

Is sodium hexametaphosphate a preservative?

Sodium hexametaphosphate is not a preservative. It is an additive that can help to prevent the growth of microbes in food and other products. Sodium hexametaphosphate is also used in detergents and cosmetics.

Is sodium hexametaphosphate natural?

No, Sodium hexametaphosphate is a synthetic compound. It’s a salt of phosphoric acid that forms in the laboratory, and it has no naturally occurring counterpart.

The term “natural” is used to describe a chemical that occurs in nature, such as sodium chloride or magnesium sulfate.

Is SHMP Vegan?

There is no use of animal matter or products derived from animal origin in the raw material or manufacturing process, so it is vegan. It can be eaten by vegetarians and vegans as a food ingredient.

Is SHMP Halal?

Yes, due to its compliance with Islamic Law and permissibility under it, it is recognized as halal. MUI Halal certificates can also be found for some manufacturers.

Is SHMP Kosher?

Yes, the product is kosher pareve. Kosher Passover or kosher kashruth certification is possible since it meets all kashruth requirements.

Is SHMP Gluten free?

Yes, since it does not contain wheat, rye, or barley, it is gluten-free according to the FDA’s definition of gluten-free.


In this article, we will discuss sodium polyphosphate – sodium hexametaphosphate (E452i), from the following perspectives:

  • The three processes of manufacturing
  • Other uses include toothpaste, food, and water treatment.
  • Safety
  • Side effects

Are you familiar with this ingredient? Comment below and let me know what you think.

Sophie Feng

Sophie Feng

Sophie Feng is the author of gradechemical.com, she is the co-founder of the grade chemical network. She has been in grade chemical company since 2017, with a working knowledge of food chemical .

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