Trisodium Ethylenediamine Disuccinate
Also known as Trisodium EDDS, Na3-EDDS, [S,S]-Ethylenediamine-N,N'-disuccinic acid trisodium salt, Trisodium [S,S]-ethylenediamine-N,N'-disuccinate
“CIR Expert Panel says: safe as used in cosmetics.”
Trisodium Ethylenediamine Disuccinate (Trisodium EDDS; CAS 178949-82-1; C10H13N2Na3O8) is the trisodium salt of [S,S]-ethylenediamine-N,N'-disuccinic acid, a biodegradable aminopolycarboxylate chelating agent. It is a structural isomer of EDTA but distinct in its stereochemistry: the disuccinate backbone is chiral and the S,S-isomer is biodegradable under environmental conditions, which is why EDDS is positioned as a 'green chemistry' alternative to disodium EDTA in personal-care and detergent applications. In cosmetic formulations it functions as a chelator, binding divalent metal ions (Ca2+, Mg2+, Fe2+, Cu2+) to improve formulation stability, enhance preservative efficacy, and reduce metal-catalyzed oxidation of sensitive actives. The Cosmetic Ingredient Review Expert Panel assessed Trisodium Ethylenediamine Disuccinate together with the related Tetrasodium Iminodisuccinate and concluded both are safe in cosmetics in the present practices of use and concentration (CIR Final Report March 31, 2023; Panel Meeting March 6-7, 2023). The Panel noted that in a dermal toxicokinetic rat study approximately 11.1% of the applied dose was absorbed in males and 5% in females, and that oral toxicokinetic data showed >60% fecal excretion within 24 hours with minimal tissue retention (0.136% in males, 0.153% in females at 72 hours). The 2023 assessment observes that in 2002 the Panel had already reviewed EDTA (the structural isomer) and found it safe, and that in 2019 the Panel reaffirmed that EDTA conclusion; the 2023 assessment extends the safety determination to the EDDS stereoisomer. Note: the CIR 2018 Quick Reference Table does not list Trisodium Ethylenediamine Disuccinate as a standalone row because the 2023 final report post-dates the QRT — the 2023 CIR PDF is the authoritative ingredient-specific source (analogous to how Propanediol is covered by the 2018 Alkane Diols final report rather than the QRT).
Biodegradable 'green chemistry' alternative to disodium EDTA — the S,S-stereoisomer is biodegradable under environmental conditions, addressing the persistence concerns associated with EDTA
Chelating agent that sequesters divalent metal ions (Ca2+, Mg2+, Fe2+, Cu2+), improving formulation stability, enhancing preservative efficacy, and reducing metal-catalyzed oxidation of sensitive actives
CIR Expert Panel concluded safe in cosmetics in the present practices of use and concentration (CIR Final Report March 31, 2023) — assessment also covers Tetrasodium Iminodisuccinate as a related amine succinate dimer
Commonly used in 'clean beauty' and environmentally-positioned skincare as an EDTA replacement
- · As with most chelators, excess dermal exposure may disrupt local skin mineral balance at very high concentrations; typical cosmetic use at 0.1-1% carries no such concern
Approximately 11% dermal absorption in male rats and 5% in female rats (CIR 2023) — higher than typical large-MW chelators; considered acceptable by the Panel given the absence of systemic toxicity in the available data
CIR Safety Assessment of Trisodium Ethylenediamine Disuccinate and Tetrasodium Iminodisuccinate as Used in Cosmetics (Final Report, March…
“The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of Trisodium Ethylenediamine Disuccinate and Tetrasodium Iminodisuccinate as used in cosmetics. These ingredients are reported to function in cosmetics as chelating agents. The Panel reviewed the available data to determine the safety of these ingredients, and concluded that Trisodium Ethylenediamine Disuccinate and Tetrasodium Iminodisuccinate are safe in cosmetics in the present practices of use and concentration as described in the safety assessment.”— FR_TrisodiumEthylenediamineDisuccinate_032023.pdf, Abstract (p. 3)