CAS 7783-40-6 is ferrous sulfate heptahydrate, an inorganic iron(II) sulfate compound with the formula FeSO4·7H2O. It is commonly recognized as a pale green to blue-green crystalline material and is also known as iron(II) sulfate heptahydrate or green vitriol. At Azeal Materials, we supply this chemical for qualified industrial, agricultural, water-treatment, and formulation applications according to the required specification and documentation.
Please visit our website for more information on this topic.
Ferrous sulfate heptahydrate is used where a soluble source of ferrous iron is needed, including micronutrient fertilizers, iron supplements, wastewater treatment, chemical processing, and selected industrial formulations. Its technical suitability depends on purity, iron content, moisture condition, particle size, packaging, and the buyer’s regulatory requirements. Because ferrous iron can oxidize to ferric iron during storage or processing, correct handling and specification control are important.
Ferrous sulfate heptahydrate is the hydrated form of ferrous sulfate, meaning that each formula unit contains seven molecules of water of crystallization. Its approximate molecular weight is 278.01 g/mol, while the anhydrous form has a different composition and molecular weight. This distinction matters because purchasing an incorrect hydrate form can change the calculated dosage and the actual amount of iron or ferrous sulfate delivered.
Commercial ferrous sulfate heptahydrate is generally supplied as crystals, granules, or a powder, depending on the production route and customer requirements. Fresh material is commonly associated with a green appearance, but color can vary with particle size, oxidation, moisture exposure, and impurities. I recommend treating appearance as an initial identification point rather than a substitute for a certificate of analysis or application-specific testing.
| Property | Typical identification |
|---|---|
| CAS Number | 7783-40-6 |
| Common name | Ferrous sulfate heptahydrate |
| Chemical formula | FeSO4·7H2O |
| Approximate molecular weight | 278.01 g/mol |
| Iron oxidation state | Ferrous iron, Fe(II) |
| Physical form | Crystalline, granular, or powdered solid |
The primary function of ferrous sulfate heptahydrate is to provide a water-soluble source of ferrous iron. In agriculture, this can support the correction of iron deficiency when the product, application rate, soil condition, and crop requirements are appropriately matched. In industrial treatment, the ferrous ion can participate in chemical reactions that support contaminant removal or process control.
Ferrous sulfate also contributes sulfate ions, which may be relevant to the overall formulation or treatment chemistry. However, it should not be selected only because it contains iron; the buyer must also assess acidity, solubility, impurities, oxidation behavior, and compatibility with other ingredients. For this reason, I normally recommend defining the end use before confirming the grade and packaging.
Ferrous sulfate heptahydrate is used in fertilizers, soil amendments, and micronutrient blends designed to provide iron. It may be considered where iron deficiency is identified or where a formulation requires a soluble iron salt. Application performance can vary according to soil pH, moisture, organic matter, application method, and crop sensitivity, so agronomic instructions should be established by the user or a qualified specialist.
Ferrous sulfate can be used as a treatment chemical in selected water and wastewater processes. Its ferrous iron may participate in reactions involving phosphate, sulfide, suspended contaminants, or oxidation-reduction chemistry, depending on the process design. The correct dose cannot be determined from the product name alone; jar testing, process data, and local discharge requirements may be needed before scale-up.
Ferrous sulfate is used as an iron source in certain animal-feed, premix, and nutritional applications. This use requires a product that meets the relevant feed or nutritional specification, including limits for unwanted elements and other impurities. I do not recommend using a general industrial grade in feed or human-related applications unless the buyer has confirmed the applicable regulatory and quality requirements.
Industrial users may use ferrous sulfate heptahydrate in pigment production, chemical synthesis, laboratory formulations, and other processes requiring a ferrous sulfate source. Its use in colorants and iron-based materials depends on impurity control and the desired final shade or reaction profile. Process engineers should evaluate the material together with temperature, pH, residence time, and the compatibility of other raw materials.
For more information, please visit Azeal Materials.
The most important distinction is between ferrous sulfate heptahydrate and anhydrous ferrous sulfate. These are chemically related but are not interchangeable on a mass-for-mass basis because their water content and molecular weights differ. Buyers should state the CAS number, formula, and required form clearly on the purchase specification.
Supply may also differ by physical form, such as powder, crystals, or granules. Fine powders can dissolve or disperse quickly but may create more dust, while larger particles may provide easier handling in some bulk processes. The best option depends on dosing equipment, dissolution requirements, transport conditions, and the buyer’s storage system.
“Industrial grade,” “agricultural grade,” and “feed grade” are not universal substitutes for a complete technical specification. A buyer should request the actual assay or iron-content range, moisture information, insoluble matter, heavy-metal limits where relevant, and test methods. If the product is intended for regulated use, the customer should also confirm whether additional documentation or approvals are required in the destination market.
For most B2B purchases, the first review should cover chemical identity, ferrous sulfate heptahydrate content, total iron or elemental iron content, water content, and appearance. Buyers should also determine whether the material must remain predominantly in the Fe(II) state during the expected storage and transport period. A certificate of analysis should be evaluated against the agreed purchase specification rather than accepted as a generic quality statement.
| Specification area | Why it matters |
|---|---|
| Identity and hydrate form | Confirms that the material is CAS 7783-40-6 and prevents substitution with another iron sulfate form. |
| Assay or iron content | Supports dosage calculations, formulation consistency, and process control. |
| Impurity profile | Helps assess suitability for agricultural, treatment, feed, or industrial use. |
| Particle size and physical form | Affects flowability, dust generation, dissolution, and dosing performance. |
| Packaging and storage condition | Helps protect the product from moisture, contamination, and unnecessary oxidation. |
Ferrous sulfate heptahydrate should generally be stored in a dry, well-ventilated area using packaging suitable for the product and transport conditions. Containers should be kept closed when not in use, and the material should be protected from excessive moisture and contamination. Workplace handling should follow the applicable safety data sheet, including recommendations for personal protective equipment, dust control, and spill response.
Exposure to air and moisture may contribute to oxidation of ferrous iron to ferric iron and can alter color or product performance. Caking may also occur if the material absorbs moisture or experiences unfavorable storage conditions. I recommend that buyers confirm the expected storage duration, warehouse environment, packaging format, and first-in-first-out inventory practice before ordering large volumes.
A suitable supplier should be able to confirm the chemical identity, available grade, physical form, packaging, and batch documentation before quotation. I also recommend asking for a representative specification or certificate of analysis format so that the purchasing and technical teams can review the same quality parameters. For international procurement, buyers should additionally clarify export documents, labeling, palletization, shipping terms, and destination-country requirements.
At Azeal Materials, we approach CAS 7783-40-6 sourcing by first understanding the customer’s application and then matching the requested product form, quality parameters, and delivery plan. We can discuss industrial, agricultural, treatment, and other qualified use cases without assuming that one specification fits every application. Before shipment, buyers should confirm the final specification, quantity, packaging, documentation, and inspection expectations in writing.
CAS 7783-40-6 is ferrous sulfate heptahydrate, a hydrated Fe(II) sulfate used as a soluble iron source across agricultural, water-treatment, nutritional, and industrial applications. It can be an appropriate choice when the process requires the heptahydrate form and the product meets the required iron, impurity, physical, and documentation specifications. It is not automatically interchangeable with anhydrous ferrous sulfate or with products intended for a different regulatory category.
As a practical next step, define your application, required grade, dosage basis, particle size, packaging, annual volume, and destination market. Then request the relevant specification, certificate of analysis, safety documentation, and quotation from a qualified supplier. Contact Azeal Materials with your CAS 7783-40-6 requirements so we can review the technical parameters and prepare a suitable B2B supply proposal.
If you want to learn more, please visit our website CAS：7783-40-6.