EDTA-2Na: Uses, Properties, Safety & Applications Guide
EDTA-2Na, also known as Disodium Ethylenediaminetetraacetate, is a versatile chelating agent widely used across industries worldwide. As a water-soluble compound, it plays a critical role in binding metal ions, preventing oxidation, and stabilizing formulations—making it an indispensable ingredient in cosmetics, food, pharmaceuticals, water treatment, and more. This comprehensive guide covers everything you need to know about EDTA-2Na, including its chemical properties, key applications, safety guidelines, and frequently asked questions, helping you understand its value and proper use.
What is EDTA-2Na? (Disodium Ethylenediaminetetraacetate)
EDTA-2Na is the disodium salt of Ethylenediaminetetraacetic acid (EDTA), a synthetic amino polycarboxylic acid with strong chelating capabilities. Its chemical formula is C₁₀H₁₄N₂Na₂O₈ (dihydrate form: C₁₀H₁₄N₂Na₂O₈·2H₂O) with a molecular weight of 372.24, and it has a CAS number of 6381-92-6. Unlike pure EDTA, which has low water solubility, EDTA-2Na is highly soluble in water (50g/100mL at 20℃) and maintains stable chelating performance across a wide pH range (3-11), making it the preferred form for industrial and commercial applications.
The key characteristic of EDTA-2Na is its ability to act as a hexadentate ligand, meaning it can form stable, water-soluble complexes (called chelates) with almost all metal ions—including calcium, magnesium, iron, copper, and lead. This chelation process deactivates metal ions, preventing them from causing discoloration, degradation, or spoilage in products, which is why it’s commonly referred to as a “stabilizer” or “preservative synergist” in various industries.
Key Properties of EDTA-2Na
Understanding the physical and chemical properties of EDTA-2Na is essential for its effective use. Below are its most important characteristics:
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Physical Appearance: White, odorless, crystalline powder or granular solid with a slightly salty taste.
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Solubility: Highly soluble in water; insoluble or very slightly soluble in ethanol, ether, and other organic solvents.
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pH Stability: Effective across a pH range of 2-10, with optimal performance in acidic to neutral conditions (pH 4-6).
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Chelating Capacity: 1 gram of EDTA-2Na can bind approximately 150mg of CaCO₃ equivalent ions, with high selectivity for metal ions like Fe³⁺ (log K=25.1), Ca²⁺ (log K=10.6), and Mg²⁺ (log K=8.7).
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Thermal Stability: Decomposes at temperatures above 200℃, making it suitable for high-temperature processing (e.g., food canning, cosmetic heat formulation).
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Purity Standards: Cosmetic and food-grade EDTA-2Na typically requires a purity of ≥99% with heavy metal content ≤10ppm.
EDTA-2Na Uses & Applications (By Industry)
EDTA-2Na’s versatile chelating properties make it a staple in multiple industries. Below are its most common applications, organized by sector—each aligned with high-volume Google search terms for SEO optimization.
1. Cosmetics & Personal Care Industry
In cosmetics and personal care products, EDTA-2Na is primarily used as a formulation stabilizer and preservative synergist. It addresses two key challenges: metal ion contamination (from water or raw materials) and product degradation over time.
Common uses include:
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Stabilizing skincare products (moisturizers, serums, cleansers) by preventing oxidation of active ingredients (e.g., vitamin C, peptides) and discoloration caused by metal ions.
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Enhancing preservative efficacy (e.g., with phenoxyethanol or ethylhexylglycerin) by chelating metal ions that support microbial growth.
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Preventing soap scum and hard water deposits in shampoos, body washes, and soaps by binding calcium and magnesium ions in water.
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Maintaining the texture and consistency of emulsions (e.g., lotions, creams) by preventing ingredient separation.
Typical usage concentration in cosmetics ranges from 0.01% to 0.5%, with no direct skincare benefits but critical for product longevity and stability.
2. Food Industry
EDTA-2Na is approved as a food additive (E386) in many countries, used primarily as anantioxidant synergist, color stabilizer, and preservative. It helps maintain food quality by preventing metal-catalyzed oxidation and spoilage.
Common uses include:
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Preserving canned foods (aquatic products,糖水栗子, vegetables) by preventing discoloration, texture loss, and the formation of struvite (glass-like crystals) in seafood cans.
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Inhibiting browning in fruits, vegetables, and starch-based products (e.g., flour) by chelating copper ions that activate polyphenol oxidase enzymes.
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Extending the shelf life of dried fruits, jams, and vegetable purees by preventing oxidation of fats and vitamins (e.g., vitamin C).
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Stabilizing beverages, solid seasonings (e.g., chicken essence), and animal feed by chelating harmful metal ions and enhancing preservative activity.
Usage limits are regulated by food safety standards: for example, a maximum of 0.25g/kg in canned foods and 0.07g/kg in jams and vegetable purees.
3. Pharmaceutical Industry
In pharmaceuticals, EDTA-2Na serves as a stabilizer and chelating agent, ensuring the efficacy and safety of medications. It is also used in medical treatments for metal poisoning.
Common uses include:
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Stabilizing injectable medications (e.g., pantoprazole sodium, tinidazole sodium chloride injection) by preventing oxidation and the formation of insoluble particles.
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Treating lead poisoning, hypercalcemia, and eye calcium deposits by chelating excess metal ions in the body and facilitating their excretion.
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Enhancing the stability of oral and topical medications by preventing metal-catalyzed degradation of active ingredients.
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Used in laboratory settings as a reagent for metal ion titration and analysis.
4. Water Treatment & Environmental Engineering
EDTA-2Na is a valuable water treatment agent due to its ability to chelate heavy metal ions and prevent scale formation. It is used in both industrial and environmental applications.
Common uses include:
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Treating industrial wastewater and drinking water by chelating calcium, magnesium, iron, and manganese ions, preventing scale buildup in pipes and equipment.
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Remediating soil and water contaminated with heavy metals (e.g., As, Cd, Cu, Pb) by chelating these ions and making them easier to remove.
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Improving the efficiency of water-based cleaning processes (e.g., boiler cleaning) by softening hard water and enhancing detergent performance.
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Analyzing metal ion concentrations in water and wastewater using EDTA-2Na络合滴定法, a simple and environmentally friendly method.
5. Other Industries
EDTA-2Na also finds applications in:
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Chemical & Polymer Industry: Used as a polymerization activator (e.g., in butadiene-styrene latex) and a reaction terminator (e.g., in acrylic fiber production).
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Agriculture: Used as a spray additive, water purifier, pH adjuster, and coagulant to improve pesticide efficacy and soil quality.
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Metallurgy & Recycling: Enhancing the recovery of gold and other metals from ores by chelating interfering metal ions (e.g., copper).
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Laboratory & Analysis: Used as a reagent for detecting heavy metals (e.g., lead, cadmium) in plastics, food, and environmental samples.
EDTA-2Na Safety & Handling Guidelines
EDTA-2Na is considered safe when used in accordance with industry regulations and guidelines. However, proper handling is essential to avoid potential hazards. Below is a summary of safety information based on SDS (Safety Data Sheet) guidelines:
1. Health Hazards
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Skin Contact: May cause mild irritation (e.g., redness, itching) in sensitive individuals. Prolonged contact should be avoided.
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Eye Contact: Can cause moderate to severe eye irritation. In case of contact, rinse thoroughly with water for at least 15 minutes and seek medical attention if irritation persists.
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Inhalation: Inhalation of dust may irritate the respiratory tract. Use in well-ventilated areas and wear a dust mask if necessary.
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Ingestion: Harmful if swallowed in large quantities. Do not induce vomiting; seek medical attention immediately if ingested.
2. Safe Handling & Storage
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Wear appropriate personal protective equipment (PPE): gloves, eye protection (goggles), and a dust mask when handling the powder form.
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Store in a cool, dry, well-ventilated area, away from incompatible materials (e.g., strong acids, oxidizing agents) and direct sunlight.
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Keep containers tightly closed when not in use to prevent moisture absorption and dust formation.
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Avoid spilling into drains or the environment; clean up spills promptly using appropriate methods (e.g., sweeping into a sealed container for disposal).
3. Environmental Considerations
EDTA-2Na has low biodegradability (less than 10% in 28 days), which may lead to environmental accumulation. The EU REACH regulation recommends a maximum usage concentration of 0.2% in products to minimize environmental impact. For eco-friendly formulations, biodegradable alternatives (e.g., GLDA, sodium gluconate) are recommended.
EDTA-2Na FAQs (Frequently Asked Questions)
Below are answers to the most common questions about EDTA-2Na, optimized for Google search intent:
Q1: What is the difference between EDTA and EDTA-2Na?
EDTA (Ethylenediaminetetraacetic acid) is the parent compound, but it has low water solubility. EDTA-2Na is the disodium salt of EDTA, which is highly water-soluble and more stable across a wider pH range. EDTA-2Na is the preferred form for most industrial and commercial applications due to its better solubility and ease of use.
Q2: Is EDTA-2Na safe for skin?
Yes, EDTA-2Na is considered safe for skin when used in low concentrations (0.01% to 0.5%) in cosmetics. It is approved by regulatory bodies like the FDA and Cosmetic Ingredient Review (CIR) and does not target the skin’s natural minerals—only external metal ions (e.g., from water or packaging).
Q3: What is EDTA-2Na used for in food?
In food, EDTA-2Na is used as an antioxidant synergist, color stabilizer, and preservative. It prevents discoloration, oxidation, and spoilage by chelating metal ions, extending the shelf life of canned foods, dried fruits, jams, and other products. Its usage is regulated by food safety standards to ensure safe consumption.
Q4: Can EDTA-2Na be used in water treatment?
Yes, EDTA-2Na is widely used in water treatment to chelate heavy metal ions (e.g., iron, calcium, magnesium), prevent scale formation in pipes and equipment, and remediate contaminated water and soil. It is also used in laboratory analysis to measure metal ion concentrations in water samples.
Q5: What are the alternatives to EDTA-2Na?
Common alternatives to EDTA-2Na include EDTA-4Na (better for alkaline formulations like soaps), GLDA (biodegradable, eco-friendly), sodium gluconate (mild chelating agent), and citric acid (for low-chelation applications). The choice depends on the application, pH requirements, and environmental considerations.
Conclusion
EDTA-2Na is a versatile, cost-effective chelating agent that plays a critical role in numerous industries, from cosmetics and food to pharmaceuticals and water treatment. Its ability to bind metal ions, stabilize formulations, and prevent degradation makes it an indispensable ingredient for maintaining product quality and efficacy. By following safety guidelines and regulatory limits, EDTA-2Na can be used safely and effectively in a wide range of applications.
Whether you’re formulating cosmetics, preserving food, treating water, or developing pharmaceuticals, understanding EDTA-2Na’s properties and applications is key to leveraging its full potential. For more detailed information on specific use cases or regulatory compliance, consult industry-specific guidelines or technical data sheets (TDS) for EDTA-2Na.
