Disodium EDTA dihydrate

Disodium EDTA dihydrate (CAS 6381-92-6) is the dihydrate form of the disodium salt of ethylenediaminetetraacetic acid, commonly sourced under the abbreviation EDTA disodium.

Where is Disodium EDTA dihydrate used?

• Personal care and cosmetics: stabilizes formulations by deactivating trace metals, preventing degradation of preservatives or rancidity in creams, shampoos, and lotions
• Food and beverage: prevents metal-catalyzed oxidation in canned goods and dressings, particularly effective in seafood products where color and shelf life are critical quality parameters
• Water treatment: sequesters calcium and magnesium ions, controlling scale formation in industrial systems
• Pharmaceutical manufacturing: enhances preservative efficacy in ophthalmic and injectable formulations by chelating metal cofactors that support microbial growth in sensitive medical products
• Technical grade serves textile processing and leather treatment.
• Small amounts act as an economical antioxidant synergist in emulsions, oils, and fragranced products.
• Binds metal ions such as calcium, magnesium, iron, copper, manganese, and zinc into stable water-soluble complexes.
• In peroxide bleaching, protects hydrogen peroxide and peracetic acid systems from catalytic decomposition by iron and manganese.
• In bottle washing machines with deposits, prevents calcium carbonate buildup on glass and machine parts and helps remove labels and glue without leaving stains.

Good to know: By binding metal ions, it prevents oxidation, discoloration, and microbial activity. Standard grades include food-grade (FCC), USP, BP, and Ph. Eur.

Formulation notes

• Used at 0.05% to 0.5% in finished products.
• To dissolve, add to the water phase at the beginning of the batch with good mixing before surfactants, thickeners, or electrolytes; warm water (40-60°C) speeds up the process.
• In strongly caustic environments above pH 13, formulators often combine with sodium gluconate or phosphonates; EDTA excels at calcium control while gluconate keeps iron and calcium in solution.
• Hypochlorite and other chlorine-releasing chemicals decompose EDTA and partially break existing complexes; EDTA and bleach should not be combined in the same product.

Typical specification

• Purity of 99.0 to 101.0%.

Regulatory status

• The INCI name for cosmetic grade is Disodium EDTA.
• Subject to EU REACH registration.
• The safety of disodium EDTA and related ingredients was assessed by the Cosmetic Ingredient Review (CIR) Expert Panel.
• At concentrations used in cosmetic and personal care products, EDTA and related ingredients were not dermal irritants or sensitizers.

Storage, packaging and handling

• Should be stored cool, dry, and well sealed to maintain product quality.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.