EDTA, DISODIUM IRON

CAS: 14729-89-6 SEQUESTRANT, STABILIZER OR THICKENER

EDTA, DISODIUM IRON (CAS 14729-89-6) is a metal chelate used for its sequestrant, stabilizer, or thickener functions in food-related applications. It appears in regulatory inventories such as the FDA EAFUS database for indirect food additives, primarily associated with adhesives or components of food packaging.

What It Is

EDTA, DISODIUM IRON is a coordination complex of iron(II) with the ethylenediaminetetraacetate (EDTA) ligand. It is a metal chelate with a central ferrous ion bound to the EDTA structure, creating a stable complex that can bind additional metal ions. This compound is recognized by the Chemical Abstracts Service under CAS number 14729-89-6 and exists in various synonymous forms reflecting its chemical identity and structure. In the context of food science, it is classified by its technical function as a sequestrant, stabilizer, or thickener. Sequestrants are additives that bind trace metal ions, which can otherwise catalyze oxidation or destabilize food systems; stabilizers help maintain uniform dispersion of ingredients; and thickeners influence the textural properties of certain formulations. Although EDTA-based compounds are more commonly discussed in general food additive lists, this specific iron complex is less frequently used directly as a food ingredient and more often appears in inventories for indirect use, such as in adhesives or coatings for food contact materials. The term "EDTA, DISODIUM IRON" reflects the disodium salt form bound to iron, differentiating it from other EDTA salts such as disodium EDTA or calcium disodium EDTA. It is not typically used for direct nutritional fortification, although related iron-EDTA chelates are studied as potential iron sources. The compound’s primary relevance in food regulation stems from its functional properties as a chelating agent that can interact with metal ions, support stability in complex mixtures, or play a role in packaging components rather than as a direct food ingredient.

How It Is Made

The manufacturing of EDTA, DISODIUM IRON starts with the preparation of ethylenediaminetetraacetic acid (EDTA), a well-known chelating agent formed by the reaction of ethylenediamine with chloroacetic acid under controlled conditions. This base EDTA molecule contains multiple sites capable of binding metal ions, making it an effective chelator. To produce the disodium form, EDTA is neutralized with sodium hydroxide, forming the disodium salt with enhanced water solubility. To incorporate iron into the EDTA structure, a soluble ferrous salt (such as ferrous sulfate) is introduced into an aqueous solution of the disodium EDTA. The iron(II) ions coordinate with the EDTA ligand in solution, displacing sodium ions to form the iron-EDTA chelate complex. The resulting complex is typically isolated by controlled crystallization and drying. The process parameters, such as pH, temperature, and stoichiometric ratios, are managed to favor the stable formation of the iron(II) complex rather than other metal species or oxidation states. In industrial practice, purity specifications are important to ensure the chelate complex meets quality criteria for its intended application. This includes limits on free EDTA, unreacted metal ions, and other impurities. Because EDTA complexes can be sensitive to oxidation, manufacturing environments often control oxygen exposure to prevent unwanted oxidation of the iron center from ferrous (Fe2+) to ferric (Fe3+). The production of disodium iron EDTA follows similar principles to other metal-EDTA complexes but with specific attention to the stability and solubility characteristics of the iron form. The resulting compound is a finely crystalline powder or granule that can be further used in formulation or packaging systems where chelation of metal ions is desired.

Why It Is Used In Food

EDTA, DISODIUM IRON is used in food-related contexts primarily for its metal-chelating properties. As a chelating agent, it binds polyvalent metal ions that might otherwise participate in undesirable reactions such as oxidation. In complex food systems or formulations, trace metals like iron, copper, and nickel can accelerate oxidation of fats and other constituents, leading to changes in flavor, aroma, nutrient quality, or color. By forming stable complexes with these metals, a sequestrant like EDTA, DISODIUM IRON can help maintain the sensory and chemical integrity of products. The sequestration of metal ions also supports the functionality of other additives. For example, stabilizers and emulsifiers can perform more consistently when transition metals are bound, as free metals can disrupt the balance between phases in emulsions or gel matrices. In thicker systems, where ingredient interactions are complex, chelation can help maintain uniform texture and prevent phase separation or discoloration over shelf life. EDTA-related compounds are chosen for these roles when specific metal-binding capacity is needed and when the formulation requires a compound that is soluble in water or compatible with other aqueous components. It is important to note that EDTA, DISODIUM IRON itself is not a traditional nutrient fortifier like iron salts used for direct dietary supplementation. Its use tends to be more specialized, such as in adhesives or coatings that may contact food, rather than as a direct additive in the food matrix for consumption. In these indirect uses, the sequestrant and stabilizing functions can contribute to the performance of coatings or packaging materials, ensuring that they adhere properly or maintain their properties over time. The chelating behavior is central to why a compound like EDTA, DISODIUM IRON is included in regulatory inventories and technical use listings.

Adi Example Calculation

The following example illustrates how an ADI concept is used in practice, using a hypothetical ADI value. Suppose a regulatory authority has established an ADI of X mg/kg body weight per day for a related EDTA salt. To estimate safe exposure for an adult weighing 70 kg, multiply the ADI by body weight: ADI (X mg/kg) * 70 kg = Total allowable daily intake in mg. For example, if the ADI were 1 mg/kg body weight per day, a 70 kg adult could theoretically consume up to 70 mg of the compound daily without exceeding the ADI. This calculation is illustrative and not specific to EDTA, DISODIUM IRON, as dedicated numeric ADIs for this compound are not established in accessible authoritative documents. Instead, the example demonstrates how ADIs for related compounds are applied to body weight to set exposure limits. Such calculations help food scientists, toxicologists, and regulators estimate whether proposed uses of additives could lead to exposure levels within or beyond safety margins.

Safety And Health Research

Safety assessments for EDTA and related metal chelates focus on their chemical behaviour, toxicological profiles, and exposure under normal use conditions. Regulators evaluate substances such as EDTA salts by considering their potential for systemic absorption, metabolism, and any indications of toxicity from short-term or long-term studies. For generic EDTA compounds, a large body of toxicological data exists for various salt forms, indicating low acute toxicity and limited evidence of genotoxicity or carcinogenicity at levels relevant to additive exposure. These conclusions arise from aggregated studies across different EDTA salts rather than specific data on the disodium iron complex, and available evidence suggests that the chelated form dissociates under physiological conditions into iron and the EDTA ligand. The iron is handled as a nutrient by biological systems, while EDTA is poorly absorbed and largely excreted unchanged. Toxicological research typically examines endpoints such as acute toxicity, chronic toxicity, reproductive and developmental effects, and genotoxic potential. Negative or inconclusive results from such studies on related EDTA salts support a general understanding that EDTA complexes do not present significant hazards at controlled exposure levels. Because disodium iron EDTA may not dissociate completely under all conditions, assessments consider the likelihood of free EDTA and iron exposure and their individual safety profiles. Iron, as an essential nutrient, has well-characterized homeostatic mechanisms, and chelated iron forms may have different bioavailability but are not inherently more toxic than other iron sources. In addition, regulators review data related to potential by-products or impurities that could arise from manufacturing processes. The overall weight of evidence from toxicological literature and regulatory evaluations supports the view that metal-EDTA complexes, when used in compliance with established specifications and within authorized use conditions, do not pose unreasonable safety risks. However, for the specific compound EDTA, DISODIUM IRON, numeric safety limits such as acceptable daily intakes (ADIs) are not defined in widely accessible authoritative documents, and safety conclusions draw on broader EDTA assessments and the behaviour of iron chelates generally.

Regulatory Status Worldwide

EDTA, DISODIUM IRON appears in regulatory inventories for food-related substances but its status varies by region and by intended use. In the United States, it is listed in the FDA’s Food Additive Status List (formerly EAFUS) and in the Inventory of Food Contact Substances as a substance recognized for specific uses such as components of adhesives or coatings that contact food. The listing under 21 CFR 175.105 indicates that the compound is d in regulations governing adhesives and components of coatings used in food packaging, although this pertains to indirect food contact rather than direct addition to food products. Its presence in these inventories means that its use in the specified applications is acknowledged by the regulatory authority, but it is not a direct food additive in the sense of being added to food intended for consumption. In other jurisdictions, such as the European Union, regulatory frameworks for food additives require explicit inclusion on the Union list of authorized additives with assigned E numbers and conditions of use. A dedicated E number specific to EDTA, DISODIUM IRON is not readily found, and food additives based on EDTA are typically regulated under different salt forms (e.g., calcium disodium EDTA with E number E385). The absence of a distinct E number for this specific iron chelate suggests that it may not be authorized as a direct food additive under common EU additive regulations, though chelating agents with similar functions are permitted with specified purity criteria and conditions. Searches of EFSA and EU food additive databases do not reveal an explicit authorization for this specific compound, suggesting that it is more relevant to material contact applications than direct food use in the EU context. Globally, Joint FAO/WHO Expert Committee on Food Additives (JECFA) provides evaluation frameworks for food additives and their specifications. While EDTA-related compounds are evaluated in generic terms and EDTA itself has been assessed for safety, specific evaluation documents for disodium iron EDTA as a food additive are not readily found in publicly accessible JECFA specification databases. The broader assessments of EDTA and metal-EDTA complexes indicate that they can be considered safe within defined use conditions and specifications, but without a dedicated specification entry for this exact chelate, numeric guidance levels or official additive status cannot be confirmed. As such, regulatory status worldwide reflects recognition for functional roles in indirect food contact or material applications rather than as a mainstream direct food additive.

Taste And Functional Properties

EDTA, DISODIUM IRON, like many EDTA-based chelates, is generally characterized by its neutral to mildly saline taste profile. It does not contribute significant flavor on its own, and at concentrations relevant to its functional use, it is unlikely to impart a pronounced taste in food applications. This low sensory impact is one reason why EDTA compounds are attractive for technological functions where flavor neutrality is important, such as in stabilizing or processing aids. Functionally, the compound exhibits strong metal-chelating behavior, meaning it can bind divalent and polyvalent metal ions such as iron, copper, and nickel. This chelation helps prevent these metals from catalyzing oxidation reactions that can degrade food quality. In aqueous systems, the complex is water-soluble, allowing it to interact readily with metal ions present in solution or introduced through processing equipment. The stability of the iron(II)-EDTA complex contributes to its ability to maintain bound metals throughout processing conditions, including variations in temperature and pH. In terms of physical properties, the chelate is typically a crystalline solid at room temperature and dissolves in water to form clear solutions. Its behavior in heat or under acidic or basic conditions depends on the surrounding matrix, but in general, chelation remains intact under normal processing conditions used for food packaging adhesives or other indirect applications. Unlike some salts that might dissociate under certain conditions, the metal-ligand bond in an EDTA complex is robust, enabling it to fulfill its functional roles reliably. Because it does not react significantly with other food constituents and is flavor-neutral, it is suitable for use in systems where maintaining the sensory profile of the product is essential.

Acceptable Daily Intake Explained

An Acceptable Daily Intake (ADI) is a regulatory concept describing the amount of a substance that can be consumed daily over a lifetime without appreciable risk, based on toxicological evidence and safety factors. ADIs are typically established by expert committees, such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) or regional authorities like EFSA, after reviewing available toxicological data. For compounds in the EDTA family, ADIs have been set for certain salts, reflecting the amount of EDTA that can be tolerated daily. For example, calcium disodium EDTA, a related chelate, has an established ADI in some regulatory frameworks and is used to support safety assessments of similar compounds. It is important to understand that an ADI applies to the intact additive and not to individual components or breakdown products. The process of setting an ADI involves identifying a no-observed-adverse-effect level (NOAEL) from animal studies and applying safety factors to account for differences between test animals and humans, as well as variability within human populations. However, for EDTA, DISODIUM IRON specifically, authoritative sources do not provide a dedicated ADI. In such cases, safety assessments draw on data for related EDTA salts and general chelation behaviour to infer that, within authorized use levels and exposure routes, the compound does not pose significant health concerns. ADI values should never be interpreted as recommended intake targets; they are conservative limits designed to protect public health. The absence of a numeric ADI for a specific compound like EDTA, DISODIUM IRON reflects the lack of a dedicated evaluation rather than evidence of harm. When evaluating exposure and risk, regulators consider the total dietary exposure to EDTA from all sources and use established ADIs for well-characterized forms as benchmarks. For individuals and producers, ensuring that usage stays within authorized conditions and considering cumulative exposure across additives helps maintain safety within established regulatory frameworks.

Comparison With Similar Additives

EDTA, DISODIUM IRON shares its core chelating function with several related additives that also bind metal ions. One widely used chelating agent in food is disodium EDTA, which is authorized in many jurisdictions and often appears on ingredient labels to preserve color and prevent oxidation. Disodium EDTA functions similarly by forming stable complexes with metal ions, helping prevent quality degradation in foods such as beverages and dressings. Compared with EDTA, DISODIUM IRON, disodium EDTA does not already contain an iron atom, and its regulatory status as a direct food additive is more established in certain contexts. Calcium disodium EDTA is another related compound commonly used as a sequestrant with assigned regulatory status and a defined E number in the EU. Calcium disodium EDTA is often chosen for applications where metal chelation is needed but with a different cationic balance that can influence solubility and mineral interactions. Compared with EDTA, DISODIUM IRON, calcium disodium EDTA has a long history of use and more well-defined regulatory guidance, making it a reference point when considering chelating additives. Ferric sodium EDTA is yet another related complex, used as a source of iron in fortified foods in some contexts. Its evaluation by authorities has focused on both iron bioavailability and chelating behaviour. While EDTA, DISODIUM IRON is an iron chelate like ferric sodium EDTA, the regulatory focus for the latter includes nutritional evaluation, reflecting its role in addressing iron deficiency. EDTA, DISODIUM IRON’s primary technical function remains metal sequestration and stabilization. These comparisons illustrate how different metal-EDTA complexes are selected for specific functional or nutritional roles, with regulatory status and use conditions shaped by their composition and intended application.

Common Food Applications Narrative

In food-related applications, EDTA, DISODIUM IRON is most commonly encountered in contexts where metal chelation supports the stability or performance of materials that come into contact with food products rather than as a direct consumable ingredient. For example, components of adhesives or coatings used in food packaging may include this compound to control metal ions that could otherwise affect the bonding performance or stability of the adhesive matrix. By sequestering trace metals, it helps maintain consistent adhesion and prevents discoloration or degradation during storage and use. Another area where chelating agents similar to EDTA, DISODIUM IRON appear is in processing aids for food packaging materials. In multilayer cartons or laminated structures, metal ions can interfere with the curing or setting of certain polymeric layers. Incorporating a chelating agent helps mitigate those effects, contributing to the integrity of the final package. While these uses do not involve the compound being added directly to the food itself, they are important for ensuring the quality and safety of packaged foods, aligning with regulatory frameworks that list such compounds under indirect food additives. In research and development, formulations that involve complex emulsions or stabilizers may employ metal chelates to maintain consistent performance. For instance, ready-to-drink beverages, salad dressings, or emulsified sauces often require stabilizers to keep phases from separating. Although EDTA, DISODIUM IRON is not a mainstream additive in these products, related EDTA salts are used in such formulations where metal-binding is necessary. In these examples, the chelating action contributes to product stability, helping prevent oxidation or color changes that could detract from quality. Overall, the narrative around this compound in food systems centers on indirect or supportive roles. Packaging materials, adhesives, and processing aids that interact with food during manufacturing, storage, or service may use this chelate for its functional properties. Because it does not add sensory character and can support material performance, it is relevant in specialized applications where maintaining consistency and preventing metal-induced reactions are priorities.

Safety & Regulations

FDA

  • Notes: Listed in FDA inventories for indirect food contact substances but not established as a direct food additive with numeric limits.
  • Regulation: 21 CFR 175.105 d for indirect food contact uses

EFSA

  • Notes: No specific EFSA authorization with E number identified for this exact compound; related EDTA salts are assessed separately.

JECFA

  • Notes: Dedicated JECFA specification and numeric ADI for this specific compound not found in available sources.

Sources

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