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Disodium EDTA

EDTA

Well toleratedChelatorchelatorstabiliserpreservative booster

No meaningful concern for most people; irritation is possible but rare.

Also written as: Disodium Edetate · EDTA Disodium Salt · Tetrasodium EDTA · Edetate Disodium

What it is

Disodium EDTA is the sodium salt of ethylenediaminetetraacetic acid, a synthetic molecule that grips metal ions such as iron, copper, calcium and magnesium and holds them in an inactive form. Those trace metals get into products from water, plant extracts and packaging, where they speed up rancidity, cause colour changes and weaken preservatives and surfactants. Formulators typically use 0.02-0.2%, which is far below any level at which it would act on skin. It is one of the most widely used stabilisers in the whole of cosmetics.

What it does well

  • Keeps the formula stable and helps the preservative system work

    By locking up trace metal ions, EDTA slows oxidation of oils and plant actives and improves the performance of common preservatives. This is standard, well-established formulation chemistry rather than a skin benefit.

    Strong evidence

  • Improves how cleansing and rinse-off products behave in hard water

    Binding calcium and magnesium reduces the soap scum and dulling film that hard water leaves behind, which is why it appears in many cleansers and wash-off masks.

    Moderate evidence

Worth knowing

  • Poorly biodegradable and persistent in surface water

    EDTA is not broken down by conventional biological wastewater treatment and has been measured as one of the more abundant man-made organic compounds in European rivers; once in water it can re-mobilise metals from sediment. The historical bulk of the load came from industrial uses (pulp and paper, detergents, photo processing) rather than cosmetics, but it is a genuine reason some brands switch to GLDA, EDDS or phytate.

    Matters most toPeople who weigh the environmental footprint of a product alongside its skin effects.

  • Mildly increases how much of other ingredients can pass into skin

    EDTA itself barely penetrates intact skin, but it loosens the calcium-dependent junctions between skin cells and so acts as a weak penetration enhancer for whatever else is in the formula. At the 0.02-0.2% used in cosmetics this is a formulation consideration, not a safety problem, and reported cases of contact allergy to EDTA are rare.

    Matters most toPeople with a broken or very compromised skin barrier using strongly active formulas.

Where the EU stands

No specific restriction

EDTA and its salts are not restricted or banned for cosmetic use in the EU; they appear in no Annex of the Cosmetics Regulation.

Sources (3)

Every link goes to the original: a journal, a PubMed record or an EU document.

  1. [1]
    Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA

    International Journal of Toxicology (Cosmetic Ingredient Review) · 2002

    The expert panel concluded EDTA and its salts are safe as used in cosmetics, noting that they are poorly absorbed through skin but can enhance the penetration of other ingredients, so finished formulas should be assessed as a whole.

  2. [2]
    Biodegradation of EDTA

    Applied Microbiology and Biotechnology · 1999

    EDTA is not degraded by conventional biological wastewater treatment; breakdown requires specific bacterial strains and conditions, which is why it persists in the aquatic environment.

  3. [3]
    Environmental fate and microbial degradation of aminopolycarboxylic acids

    FEMS Microbiology Reviews · 2001 · doi:10.1111/j.1574-6976.2001.tb00572.x

    How fast EDTA-type chelators break down in the environment depends heavily on which metal they are bound to, and several of the common metal complexes are effectively resistant to microbial degradation.

Masks that contain Disodium EDTA