INCI: Trisodium Ethylenediamine Disuccinate - Also known as: Trisodium EDDS, EDDS-Na3, Biodegradable Chelator

QUICK FACTS

What is Trisodium Ethylenediamine Disuccinate?

Trisodium Ethylenediamine Disuccinate (Trisodium EDDS) is a tetradentate aminopolycarboxylate chelating agent - a molecule specifically designed to bind and sequester metal ions by forming stable ring complexes with them. It is the trisodium salt of ethylenediamine disuccinic acid (EDDS), produced through biotransformation of the amino acid aspartic acid. Its key distinction from EDTA (ethylenediaminetetraacetic acid), the most historically common chelating agent in cosmetics, is its biodegradability: where EDTA persists in the environment and accumulates in water systems, Trisodium EDDS is readily biodegradable and is classified as an environmentally preferred chelating agent by regulatory bodies across the EU and US.

The chelating mechanism of Trisodium EDDS operates through its four coordinating sites - two amine nitrogens and two carboxylate groups - which wrap around metal ions (most commonly iron, copper, calcium, and magnesium) to form stable, water-soluble complexes. By sequestering these ions within the formula, the chelator prevents them from participating in Fenton-type reactions that would otherwise catalyze the oxidative degradation of sensitive actives.

At Sweet Chemistry, Trisodium EDDS is the chelating agent used in all three water-based formulas - chosen over EDTA specifically because of its biodegradability, reflecting the brand's commitment to sustainable formulation choices without compromising on the formula stability that an ingredient at this function level provides.

What does it do for skin?

Trisodium EDDS's contribution is formulation-structural rather than active skin-beneficial - but its effect on every other ingredient in the formula is direct and significant. Trace metal ions, particularly iron and copper, enter cosmetic formulas through raw materials, water, and packaging. These ions act as pro-oxidant catalysts, dramatically accelerating the oxidative breakdown of sensitive actives through metal-catalyzed free radical generation. For a formula carrying 7% THD ascorbate, Matrikynes® peptides, CoQ10, and alpha-lipoic acid - all of which are sensitive to metal-catalyzed oxidation - the consequences of unchecked metal ion activity are not cosmetic; they directly compromise active ingredient integrity and product efficacy.

By sequestering metal ions before they can participate in these reactions, Trisodium EDDS preserves the functional concentration and activity of every sensitive active in the formula from manufacturing through to the final application. In practical terms, this means the 3% Matrikynes® in the first pump is the same as in the last - the ingredient-list concentrations represent what actually reaches the skin throughout the product's shelf life and use cycle.

Trisodium EDDS also supports the preservation system's efficacy. Certain metal ions - particularly calcium and magnesium - can interfere with the activity of preservatives by forming insoluble complexes with them. By chelating these ions, Trisodium EDDS helps the preservation system function as designed, contributing to the microbial safety of the formula alongside phenoxyethanol, ethylhexylglycerin, and caprylyl glycol.

FOUND IN

In 3 Formulas

Trisodium EDDS is present in all three Sweet Chemistry water-based formulas as the biodegradable chelating agent that protects every active in each formula from metal-catalyzed oxidative degradation. It is absent from the Oil-Serum, where the waterless base and different preservation approach do not require this class of chelation.

Nourishment - All Skin Types

Barrier Repairing Hydra-Serum Trisodium Ethylenediamine Disuccinate - 1.0 oz / 30 ml

Trisodium EDDS protects the 40%-active payload of the Hydra-Serum - including 3% Matrikynes® peptides, 5% niacinamide, 3% ceramides, and the complete antioxidant system - from metal-catalyzed oxidative degradation throughout the product's shelf life.

Hydration - Dry to Normal

Elasticity Reinforcing Hydra-Cream Trisodium Ethylenediamine Disuccinate - 1.7 oz / 50 ml

In the Hydra-Cream, Trisodium EDDS preserves the integrity of 2% THD ascorbate and 3% Matrikynes® peptides - two actives that are particularly sensitive to metal-catalyzed degradation in water-based emulsions.

Hydration - Dry to Dehydrated

Elasticity Reinforcing Lipid-Cream Trisodium Ethylenediamine Disuccinate - 1.7 oz / 50 ml

In the Lipid-Cream, Trisodium EDDS maintains the active concentration and efficacy of the formula's 46%-active payload from manufacturing to last use - protecting peptides, vitamin C, antioxidants, and ceramides alike.

WORKS TOGETHER WITH

Stable Vitamin C THD Ascorbate

INCI: Tetrahexyldecyl Ascorbate.

At 2% in both creams and 7% in the Oil-Serum. Synergy Note: Vitamin C derivatives are among the actives most vulnerable to metal-catalyzed oxidation in water-based formulas. Trisodium EDDS's chelation of pro-oxidant metal ions is directly relevant to preserving THD ascorbate's activity and the formula's brightening contribution throughout its shelf life.

Enzymatic Antioxidant Thioctic Acid (Alpha-Lipoic Acid) *

INCI: Thioctic Acid.

Present in all three water-based formulas as part of the enzymatic antioxidant trio. Synergy Note: Alpha-lipoic acid's thiol group is reactive with metal ions - Trisodium EDDS's sequestration of free metal ions in the formula reduces the risk of metal-thiol interactions that could compromise the antioxidant's functional form. 

Primary Preservative Phenoxyethanol

INCI: Phenoxyethanol.

The primary antimicrobial preservative in all three water-based formulas. Synergy Note: Metal ions, particularly calcium, can form insoluble complexes with preservatives and reduce their efficacy. Trisodium EDDS's chelation of these ions supports the preservation system's full antimicrobial activity - chelation and preservation working together to maintain formula integrity.

ECM Peptide Complex Matrikynes® Bone Peptides

INCI: Hydrolyzed Cow Bone Extract.

At 3% in all four formulas. Synergy Note: Peptides can be degraded by metal-catalyzed oxidative reactions in water-based systems. Trisodium EDDS's sequestration of pro-oxidant metal ions directly protects the stability of the Matrikynes® peptide complex - ensuring the 3% concentration labeled on the formula represents what actually reaches the skin.