Heptahydrate ferrous sulfate food grade (FeSO4·7H2O) is an inorganic iron compound widely used as a nutrient fortificant and color development reagent in commercial food manufacturing. Produced as pale blue-green crystalline granules, it delivers 20.1% elemental iron by mass, making it a cost-effective iron source for food enrichment programs. The material is efflorescent in dry air and oxidizes to brown-yellow basic ferric sulfate under moist conditions, which underscores the need for controlled storage. As a manufacturer with over a decade of production experience, SUNWAY supplies this ingredient to food processors, beverage makers, and supplement formulators across more than 30 countries, with each batch accompanied by a Certificate of Analysis (COA).
Parameter | Value |
Chemical Name | Ferrous sulfate heptahydrate |
Molecular Formula | FeSO4·7H2O |
Molecular Weight | 278.02 g/mol |
CAS Number | 7782-63-0 |
EC Number | 231-753-5 |
Appearance | Pale blue-green crystals or granules |
Solubility | Soluble in water; insoluble in ethanol |
Item | Ferrous sulfate heptahydrate | Ferrous sulfate anhydrous |
Content (On the basis of FeSO4·7H2O) | 99.5-104.5 | — |
Content (On the basis of FeSO4) | — | 86.0-89.0 |
Lead (Pb), mg/Kg ≤ | 2 | 2 |
Arsenic (As), mg/Kg ≤ | 3 | 3 |
Mercury (Hg), mg/Kg ≤ | 1 | 1 |
Acid Insoluble, w% ≤ | — | 0.05 |
Commercial food manufacturers use heptahydrate ferrous sulfate as an iron fortificant in wheat flour, breakfast cereals, infant formulas, and nutritional beverages. Its high water solubility allows uniform dispersion in liquid systems, while the food-grade purity meets the heavy metal limits required by GB29211-2012 and Codex Alimentarius standards. Beverage producers often incorporate it into iron-enriched drinking water and sports drinks at dosages determined by local fortification regulations.
In fruit and vegetable processing, ferrous sulfate serves as a chromogenic reagent. It reacts with natural polyphenols in certain produce to stabilize or intensify color, particularly in canned vegetables and pickled products. Food-grade quality is essential in this application because the additive remains in the final consumable product.
Supplement formulators use heptahydrate ferrous sulfate in tablet and capsule preparations targeting iron-deficiency populations. The defined iron content (20.1% elemental iron) enables accurate dosage calculation, and the crystalline form flows reliably in high-speed tableting equipment.
Each unit is packed with a polyethylene inner bag and a compound plastic woven outer bag, with a net weight of 25 kg per bag. Palletized loads are available for container shipping, typically loading 20 MT per 20-foot container. The product must be stored in a dry, ventilated warehouse at temperatures below 30°C and relative humidity below 60%. During transport, it should be kept away from water and moisture and unloaded carefully to avoid bag damage. It must be stored separately from poisonous substances and oxidizing agents. Under proper storage conditions, the shelf life is 24 months from the date of manufacture.
Production follows the GB29211-2012 national food safety standard. The manufacturing facility operates under an ISO 9001 quality management system and HACCP-based food safety protocols. Each batch undergoes testing for content assay, lead, arsenic, mercury, and acid insoluble matter before release. Upon request, third-party inspection reports from SGS or Intertek can be provided. The product is available with Kosher and Halal certifications for clients requiring them.
Food-grade ferrous sulfate meets GB29211-2012 limits for heavy metals (lead ≤2 mg/kg, arsenic ≤3 mg/kg, mercury ≤1 mg/kg) and is produced in food-certified facilities. Agricultural grade has less stringent purity requirements and is intended for soil amendment and plant nutrition, not for direct addition to food.
Heptahydrate ferrous sulfate oxidizes in moist air to form brown-yellow basic ferric sulfate. This indicates exposure to humidity. Properly stored material retains its pale blue-green color. Slight surface oxidation does not necessarily render the product unusable, but COA data should be consulted for content verification.
The standard MOQ is one 20-foot container (approximately 20 MT). For initial evaluation, smaller trial orders of 500 kg to 1 MT can be arranged through our sales team. Custom packaging sizes (1 kg, 5 kg, 10 kg) are available for supplement and blend manufacturers upon request.