Industrial grade Food Grade99% Ferrous sulfate heptahydrate CAS 7782-63-0 7720-78-7

What is Ferrous sulfate heptahydrate?

Ferrous sulfate heptahydrate (also green vitriol or iron sulfate heptahydrate) is the heptahydrate of divalent iron sulfate and a classical iron fortifying agent in the food industry. It is usually written with the chemical formula:

FeSO4.7H2O (anhydrous FeSO4, CAS No. : 7782-63-0 (heptahydrate), 7720-78-7 (anhydrous), EINECS No. : 231-753-5, molecular weight approx. 278.01

Ferrous sulfate is a blue-green crystal or granule at room temperature and is odorless. Its melting point is approximately 64℃ (when it melts, it loses water of crystallization) and it loses all seven molecules of water of crystallization at 90℃. Specific gravity: 1.898. It is readily soluble in water (about 48.6 g/100 g at 20 °C) and forms pale green solutions in water. Ferrous sulfate effloresces readily in dry air and is oxidized in humid air to a yellowish-brown ferric salt. Food grade ferrous sulfate is refined from high purity raw material and strict food safety standards.

Molecular composition wise ferrous sulfate is a compound of ferrous ions (Fe2+) and sulfate ions (SO42-) held together by ionic bonds. It has seven molecules of water of crystallization. Ferrous ions are an important source of iron to make hemoglobin in the human body. It is a central component of hemoglobin and myoglobin and is involved in oxygen transport and cellular metabolism. Food-grade ferrous sulfate is in the form of ferrous, with high absorption and utilization rate, and thus is an ideal form for iron supplementation, which is the structural basis of its use as a food iron fortifier.

Ferrous sulfate is readily oxidized in air to give a yellowish-brown ferric salt . Chemically , ferrous sulfate readily reacts with substances such as tannic acid , affecting absorption . There is a danger of poisoning with excessive iron intake . For food-grade products, store in sealed moisture-proof and light-proof containers to prevent oxidation and spoilage.

Ferrous sulfate for food is a product in compliance with GB 29211-2012 "National Food Safety Standard for Food Additives-Ferrous Sulfate", used as an iron fortification agent in food. Like the GRAS (Generally Recognized As Safe) designation by the US FDA, food-grade products in my country also have strict requirements, mainly including:

Content (purity)

The main component, on dry basis, is in conformity with GB 29211 (generally >98%), and its content decides the effect of iron fortification and the dosage.

Heavy metal limits (e.g. lead, arsenic)

Strict limits are set for heavy metals such as lead and arsenic, which are important indicators for food safety.

Water-insoluble substance

Low water insoluble matter content is required for solution clarity and processing system cleanliness.

Free acid

The free sulfuric acid content influences the pH and taste of the product and should be controlled within the standard limits.

Clearness

The aqueous solution must be clear, free from turbidity and insoluble matter, reflecting the purity of the product and the degree of process control.

What are the uses of food-grade ferrous sulfate heptahydrate?

Food-grade ferrous sulfate is mainly used as an iron fortification agent, and its core mission is to scientifically supplement iron and prevent and treat iron deficiency anemia. Its use is mainly focused on the following areas:

1. Iron fortification in infant formula (primary use)

Iron is an essential nutrient in infant formula. As per GB 14880, ferrous sulfate is used for iron fortification of infant formula to help infants get enough iron nutrition and prevent iron deficiency anemia. It must meet baby formula standards.

2. Fortified foods e.g. modified milk powder

Ferrous sulfate is used for fortification of food categories such as milk powder, cream powder, etc. in accordance with GB 14880 to help pregnant women, lactating mothers, the elderly and certain groups of people to supplement their iron nutrition through their daily food.

3. Breakfast cereals and fortified milled products

Ferrous sulfate is used as an iron source in iron-fortified breakfast cereals, fortified flour and baked goods to help improve the iron nutrition status of staple food consumers. It is a common source of iron for fortification of cereal foods.

4. Dietary supplements and health foods (iron supplements)

Ferrous sulfate is used as a raw material for iron-fortified health foods and dietary supplements, and it provides a convenient way for people at risk of iron-deficiency anemia to supplement iron. Products must be registered or filed and labeled with the proper population and dosage.

5. Foods for Special Purposes (FSMP)

Ferrous sulfate is used as a micronutrient in the formulation of special-purpose foods to provide balanced iron nutrition to individuals suffering from malnutrition and digestive disorders. Its use should follow standards like GB 29922.

6. Dairy beverages and fortified beverages

Ferrous sulfate is one of the optional sources of iron used for fortification of beverages. It is included in some iron fortified milk drinks and nutritional drinks to help supplement iron through daily drinks.

7. Other uses

With the extension of the range of fortified foods, the application scope of food-grade ferrous sulfate continues to expand, including sports nutrition foods, school meals and prenatal nutrition packs.

Note that iron is a micronutrient that is “too much of a good thing.” The recommended daily intake of iron for Chinese residents is about 12-20 mg for adults, and foods fortified according to GB 14880 standards are safe, but iron supplementation should not be done blindly and excessively, and iron supplements and health products should be used according to a doctor’s advice. In particular, care should be taken to prevent children from accidentally ingesting iron supplements.

Summarize

Ferrous sulfate heptahydrate (FeSO4.7H2O, CAS No. 7782-63-0, anhydrous form 7720-78-7) is a blue-green crystalline solid. It is called “green vitriol”. It is easy to dissolve in water, exists in the form of ferrous iron (Fe2+), and has a high absorption and utilization rate, so ferrous sulfate is a classic iron fortification agent in the food industry. It is added to infant formula, modified milk powder and fortified rice cereals, breakfast cereals and fortified flour, iron-fortified health foods, special-purpose formula foods, and iron supplements in daily life. Food-grade ferrous sulfate, which meets the requirements of GB 29211-2012, is widely used in the food industry for iron fortification of infant formula, fortified milk powder and other nutritionally fortified foods, fortified breakfast cereals, iron supplements in health foods, special purpose formula foods and fortified dairy beverages. It is an essential iron fortification agent in food to ensure adequate iron nutrition for the population.