Many buyers mix up these three EDTA salts, leading to formula failure, safety hazards and extra costs. Below is a clear breakdown of their core traits, applicable fields, do's and don'ts for accurate selection.
1. Basic Property Overview
表格
| Product | Common Name | 1% Solution pH | Key Characteristic |
|---|---|---|---|
| EDTA-2Na | Disodium EDTA | 4.5–6.0 (mildly acidic) | Moderate solubility, widely compliant, universal mild chelator |
| EDTA-4Na | Tetrasodium EDTA | 10.0–11.0 (strongly alkaline) | High solubility, fast dissolution, stable in alkaline environments |
| EDTA-CaNa₂ | Calcium Disodium EDTA | 6.5–7.5 (neutral) | Pre-bound with calcium, no calcium depletion in human body |
2. Exclusive Application Scenarios & Usage Rules
✅ EDTA Disodium (EDTA-2Na)
Core positioning: Multi-purpose grade for food, daily chemicals and general pharmaceuticals
Main uses
Food & beverages: Prevent oxidation, discoloration and flavor degradation; extend shelf life.
Cosmetics & personal care: Stabilize formulas, avoid precipitation caused by metal ions, compatible with most skincare, shampoo and emulsion products.
General pharmaceuticals: Used as stabilizer for oral liquids, ointments and common injections.
Neutral/weakly acidic industrial water treatment.
Pros: Food/cosmetic/pharma certified, mild and low-irritant, cost-effective for regular use.
❌ Never use for: Strong alkaline systems, medical heavy metal detox.
✅ EDTA Tetrasodium (EDTA-4Na)
Core positioning: Professional industrial grade for alkaline working systems
Main uses
Industrial cleaning & heavy-duty detergents: Remove rust, scale and metal dirt, boost detergency.
Water treatment: Scale inhibition and wastewater treatment for alkaline water systems.
Textile printing & dyeing: Soften water, ensure even dyeing and avoid dye flocculation.
Alkaline liquid fertilizers: Chelate trace elements for foliar application.
Pros: Excellent water solubility, rapid dissolution, ideal for concentrated solutions and continuous production lines.
❌ Never use for: Food, oral products, mainstream leave-on cosmetics and pharmaceuticals. Its strong alkalinity causes irritation and corrosion.
✅ EDTA Calcium Disodium (EDTA-CaNa₂)
Core positioning: Special medical grade, no industrial or civilian use
Main use: Clinical treatment of heavy metal poisoning (lead, cadmium, mercury etc.). Its built-in calcium prevents the human body from losing essential calcium ions during chelation, avoiding life-threatening electrolyte disorders.
Pros: Physiologically safe, exclusive for medical detoxification.
❌ Never use for: All food, cosmetics, agriculture and general industrial production. It has low chelating efficiency for industrial needs and extremely high cost.
3. Quick Selection Cheat Sheet
If your product is food, cosmetics, common medicines, weak acid/neutral formulas → Pick EDTA-2Na
If you work on industrial cleaning, textile, alkaline water treatment, alkaline fertilizers → Pick EDTA-4Na
If for clinical heavy metal detoxification only → Pick EDTA-CaNa₂
4. Common Buying Mistakes to Avoid
Replace EDTA-2Na with EDTA-4Na for cosmetics/food: Causes product irritation, deterioration and non-compliance.
Use EDTA-2Na in high-alkaline industrial lines: Poor solubility leads to residue, pipeline blockage and poor performance.
Purchase EDTA-CaNa₂ for regular industrial chelation: Wastes cost and fails to meet production requirements.
Mix EDTA-4Na with acidic raw materials: Triggers precipitation and ruins the whole batch.