Ethylenediaminetetraacetic acid (EDTA) is an aminopolycarboxylic acid with the formula [CH₂N(CH₂CO₂H)₂]₂. This white, water-soluble solid is widely used to bind to iron (Fe²⁺/Fe³⁺) and calcium ions (Ca²⁺), forming water-soluble complexes even at neutral pH. It is thus used to dissolve Fe- and Ca-containing scale as well as to deliver iron ions under conditions where its oxides are insoluble. EDTA is available as several salts, notably disodium EDTA, sodium calcium edetate, and tetrasodium EDTA, but these all function similarly.

Ethylenediaminetetraacetic acid

Names
Preferred IUPAC name 2,2′,2′′,2′′′-(Ethane-1,2-diyldinitrilo)tetraacetic acid
Other names EthyleneDiamineTetraAcetic acid N,N′-Ethane-1,2-diylbis[N-(carboxymethyl)glycine] Diaminoethane-tetraacetic acid Edetic acid (conjugate base edetate) (INN, USAN) Versene
Identifiers
CAS Number	60-00-4 (free acid) Y 6381-92-6 (dihydrate disodium salt) Y
3D model (JSmol)	Interactive image
Abbreviations	EDTA, H4EDTA
Beilstein Reference	1716295
ChEBI	CHEBI:4735 Y
ChEMBL	ChEMBL858 Y
ChemSpider	5826 Y
DrugBank	DB00974 Y
ECHA InfoCard	100.000.409
EC Number	200-449-4
Gmelin Reference	144943
KEGG	D00052 Y
MeSH	Edetic+Acid
PubChem CID	6049
RTECS number	AH4025000
UNII	9G34HU7RV0 Y 7FLD91C86K (dihydrate disodium salt) Y
UN number	3077
CompTox Dashboard (EPA)	DTXSID6022977
InChI InChI=1S/C10H16N2O8/c13-7(14)3-11(4-8(15)16)1-2-12(5-9(17)18)6-10(19)20/h1-6H2,(H,13,14)(H,15,16)(H,17,18)(H,19,20) Y Key: KCXVZYZYPLLWCC-UHFFFAOYSA-N Y
SMILES OC(=O)CN(CCN(CC(O)=O)CC(O)=O)CC(O)=O
Properties
Chemical formula	C10H16N2O8
Molar mass	292.244 g·mol−1
Appearance	Colourless crystals
Density	0.860 g cm−3 (at 20 °C)
log P	−0.836
Acidity (pKa)	2.0, 2.7, 6.16, 10.26
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	−1765.4 to −1758.0 kJ mol−1
Std enthalpy of combustion (ΔcH⦵298)	−4461.7 to −4454.5 kJ mol−1
Pharmacology
ATC code	S01XA05 (WHO) V03AB03 (WHO) (salt)
Routes of administration	Intramuscular Intravenous
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H319
Precautionary statements	P305+P351+P338
NFPA 704 (fire diamond)	1 0 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1000 mg/kg (oral, rat)
Related compounds
Related alkanoic acids	Daminozide Octopine
Related compounds	Triethylenetetramine Tetraacetylethylenediamine PMDTA Bis-tris propane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references