Sodium edetate
[CAS# 64-02-8]

Identification

• Classification: Organic raw materials >> Organometallic compound >> Organic sodium
• Name: Sodium edetate
• Synonyms: EDTA tetrasodium salt; Tetrasodium ethylenediaminetetraacetate
• Molecular Formula: C₁₀H₁₂N₂Na₄O₈
• Molecular Weight: 380.17
• CAS Registry Number: 64-02-8
• EC Number: 200-573-9
• SMILES: C(CN(CC(=O)[O-])CC(=O)[O-])N(CC(=O)[O-])CC(=O)[O-].[Na+].[Na+].[Na+].[Na+]

Properties

• Density: 0.7 g/mL (Expl.)
• Melting point: 300 °C (decomp.) (Expl.)
• Solubility: 500 g/L (water 20 °C) (Expl.)

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H302-H318
• Safety Statements: P260-P261-P264-P264+P265-P270-P271-P280-P301+P317-P304+P340-P305+P354+P338-P317-P319-P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	2	H302
Skin irritation	Skin Irrit.	2	H315
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H312
Skin corrosion	Skin Corr.	1	H314
Carcinogenicity	Carc.	2	H351
Skin sensitization	Skin Sens.	1	H317

Discovery and Applications

Sodium edetate, commonly known as disodium EDTA, is a chelating agent widely used across medical, industrial, and cosmetic fields due to its capacity to bind metal ions. Chemically known as disodium ethylenediaminetetraacetic acid, this compound was first synthesized in the 1930s by Ferdinand Münz, a German chemist who recognized its potential for binding metal ions. This property of forming stable complexes with metal ions makes sodium edetate invaluable for a range of applications that require the removal or neutralization of metals.

One of the primary medical uses of sodium edetate is in chelation therapy, specifically for treating heavy metal poisoning. When administered intravenously, sodium edetate binds with toxic metal ions, such as lead, cadmium, and mercury, forming complexes that are then excreted through the urine. This therapeutic application has been crucial in managing cases of lead poisoning, which can occur due to exposure to contaminated water, old paint, or industrial pollution. Sodium edetate is also used to treat hypercalcemia, a condition where elevated calcium levels can lead to kidney problems, neurological symptoms, and other health issues. By binding to excess calcium ions, sodium edetate helps lower calcium concentrations in the blood. Its approval by health authorities like the U.S. Food and Drug Administration (FDA) for these uses highlights its importance in medicine.

Beyond medicine, sodium edetate has extensive applications in industrial and household products, where it is primarily valued for its ability to sequester metal ions. In the manufacturing of cleaning products, sodium edetate prevents the deposition of metal ions in solutions, enhancing the efficiency and longevity of these products. It is particularly effective in preventing the formation of metal deposits in water-based formulations, making it a key additive in household cleaning agents, industrial detergents, and laundry products. In water treatment plants, sodium edetate is used to control metal ion concentration, thereby enhancing water quality and minimizing scale buildup.

In the cosmetics industry, sodium edetate is commonly used in skin care, hair care, and personal care products. It acts as a stabilizer by binding metal ions that could otherwise cause product degradation or reduce effectiveness. Sodium edetate prevents metallic impurities from interacting with active ingredients, enhancing the stability and shelf life of formulations. This is especially valuable in products containing antioxidants or colorants, where metal ions might catalyze unwanted reactions. For this reason, sodium edetate is frequently found in shampoos, conditioners, moisturizers, and sunscreens, ensuring that these products remain effective over time.

Sodium edetate also plays a vital role in food preservation. As a sequestrant, it helps prevent discoloration, texture changes, and flavor alterations that can occur due to metal ion interaction with food ingredients. Sodium edetate is approved for limited use in some food products, particularly in canned vegetables, soft drinks, and dressings. Its inclusion helps maintain product appearance and flavor stability, especially when food is exposed to varying storage conditions.

Sodium edetate’s ability to control metal ion concentrations is further harnessed in laboratory and analytical chemistry. It serves as a titrant in complexometric titration methods, allowing chemists to measure metal ion concentrations in solutions with high precision. This application is particularly important in fields such as environmental monitoring, where trace metal analysis is required to assess pollution levels, and in pharmaceuticals, where precise ion quantification is essential.

In conclusion, sodium edetate’s broad utility in chelation therapy, industrial processes, cosmetics, food preservation, and analytical chemistry demonstrates its exceptional versatility and efficacy in managing metal ions. Its ability to form stable complexes continues to make it an invaluable compound in applications where metal ion control is essential.

References

1969. Determination of iron in solutions containing iron complexes. Journal of Clinical Pathology, 22(3).
DOI: 10.1136/jcp.22.3.301

2024. Soil nutrients, phosphatase activities and phosphorus species distribution in soils amended sheep manure biochar. Journal of Soils and Sediments, 24(7).
DOI: 10.1007/s11368-024-03869-9