Ferrous citrate stands as a complex iron salt formed by the reaction of iron(II) ions with citric acid. This substance arrives in the chemical world as a grayish-green powder or sometimes appears as slightly yellow, crystalline grains. Its molecular formula, C6H6FeO7, offers a clear snapshot for chemists tracing the combination of iron with citric acid’s well-known organic skeleton. The molecular weight clocks in at about 245.96 g/mol, placing it in a comfortable spot among other iron chelates designed for nutritional or industrial tasks. Its Chemical Abstracts Service (CAS) Registry Number is 2338-05-8. On the global market, import and export activities usually reference the HS Code 29181500 for proper customs clearance.
Solid at room temperature, ferrous citrate keeps things stable under modest environmental swings. Grainy crystals, powder, and sometimes lumps or flakes land in shipping barrels, and the material resists caking unless exposed to moisture. True to the behavior of many chelates, it dissolves in water at a moderate rate and gives off a faintly earthy metallic scent. The density often registers near 1.8 g/cm³, close to other iron-organic complexes, so it requires careful scooping and weighing. No one can ignore the brownish tinge liquids take on after ferrous citrate dissolves — a clear sign iron is present and ready for action. Structurally, this compound features the citric acid molecule wrapped around the iron atom, producing a chelate that helps keep the iron soluble and more bioavailable in solution than its simpler iron salt cousins.
Industries and labs order ferrous citrate in grades tailored for food fortification, nutritional supplements, and specialty chemical synthesis. Food-grade specifications demand a ferrous iron content usually not less than 15%. High-purity lots serve pharmaceutical needs, where allowable levels of lead, arsenic, or heavy metals sit far below those found in agricultural or industrial batches. Flake and crystalline forms travel best for industrial users. Powdered ferrous citrate appeals to supplement manufacturers who blend it directly into tablets or capsules. In rare cases, pearl or bead-like granules pop up when some manufacturers modify crystallization methods for easier handling or unique blending requirements. Liquid solutions of ferrous citrate offer another route — manufacturers dissolve controlled amounts in water to deliver precise iron concentrations, handy for plant nutrition or clinical dosing.
Ferrous citrate comes as an iron(II) compound, not iron(III), so it stands less oxidized and reacts differently than ferric salts. This makes the iron more readily available for uptake in both plants and the human gut. The bonds holding the iron to the citric acid stay strong enough to keep the iron in solution at pH levels common to blood or plant root environments. That chelation stabilizes the iron, fights off oxidation, and helps delay the formation of insoluble iron hydroxide, a big problem elsewhere in the world of iron compounds. Solubility in water sits at roughly 10-15g per liter at room temperature depending on the batch, and most material dissolves into a pale green to yellowish solution. Its chemical behavior allows it to act as both a nutritional iron carrier and as a mild reducing agent in some laboratory applications.
Ferrous citrate, like many iron salts, doesn’t qualify as non-toxic, but it brings less risk than simpler ore-derived compounds when handled correctly. Inhalation of fine powder can irritate the upper respiratory tract, so gloves, goggles, and dust masks should be standard PPE. Accidental ingestion of concentrated amounts can cause gastrointestinal upset, nausea, or more serious iron poisoning — a special concern for children and pets. Avoiding eye or skin contact prevents mild irritation, though the compound’s low volatility lessens risk of airborne exposure. Disposal of large quantities must follow local regulations to keep excess iron and citrate out of ground or surface water, since both nutrients and acidity can trigger ecological impacts at high concentrations. Packaging follows hazardous materials standards for shipping chemicals, but ferrous citrate typically falls into a less-stringent regulatory category than raw iron salts due to its lower reactivity. Proper storage in tightly sealed containers wards off humidity, clumping, and unwanted oxidation.
Ferrous citrate gets made by combining ferrous salts, often sourced from iron filings or scrap dissolved in acid, with high-purity citric acid extracted from fermented molasses or corn biomass. Chemical factories keep a close eye on input purity — contaminants in base materials quickly multiply as problems down the supply chain, showing up in the form of heavy metals or off-colors in the final product. The focus on sourcing high-assay raw materials makes a big difference for supplement and pharmaceutical manufacturers, who undergo regular audits and testing. Industrial buyers sometimes use less expensive material if the use-case, like fertilizer solutions, allows slightly lower purity. Production involves careful pH control, filtration, and crystallization stages, all to keep final iron and citrate ratios within spec and avoid unwanted byproducts.
Makers and users of ferrous citrate regularly face real headaches, both technical and regulatory. Oxidation presents a constant problem — anyone who has left a ferrous solution exposed to air has seen the once-clear liquid turn rusty and brown as iron(II) quickly transforms into iron(III), creating insoluble sludge. Tackling this means producing fresh solutions just before use, storing product under nitrogen or other inert gases, or adding antioxidants to slow the reaction. Another issue lies with purity: even trace contamination with lead or arsenic draws fast attention from food safety authorities and international buyers. On the supply side, rising raw material costs or disruptions in citric acid fermentation lead to price swings that ripple through downstream industries. Keeping a short supply chain, working with reputable chemical suppliers, and pushing for improved filtration and quality control offer the most reliable ways to deliver a safe, consistent ferrous citrate product.
The world turns to ferrous citrate for available iron that dissolves well, absorbs fast, and avoids some of the harsh side effects tied to simpler iron pills. In food fortification, it shows up in cereals, beverages, and supplements, often paired with vitamin C to help with absorption. Plant nutrition industries tap it for hydroponic systems, where quick iron delivery fixes chlorosis in iron-hungry crops. Though there are many iron chelates, the organic backbone of citric acid gives ferrous citrate distinct advantages in both uptake and environmental profile — it breaks down naturally and avoids building up in soils or waterways at usual use rates. Researchers see new uses emerging in medical and environmental science, often comparing it to closely related compounds like ferrous fumarate or ferrous sulfate to spot differences in absorption, stability, or environmental safety. People shopping for supplements benefit from checking label purity, iron content, and source transparency — trust increases when manufacturers openly publish test results and follow established Good Manufacturing Practices.
