Characteristic	Description/values	Method (when relevant)
Name	Iron oxo‐hydroxide adipate tartrate IHAT	n.a.
Description	IHAT is a tartrate‐modified, nano‐disperse Fe(III) oxohydroxide, formed in an adipate buffer, with similar functional properties and primary particle size as the iron found in the ferritin core. The tartrate‐modified ferrihydrite is precipitated from an Fe(III) chloride solution in the presence of sodium tartrate and adipate buffer. Fe(III)‐oxohydroxide nanocores are constrained from growth and crystallisation by being captured inside a corona of tartrate with some dispersion‐aiding adipic acid and tartaric acid mixed into the formulation.	ICP‐OES TEM and EDX XRD, STEM, FTIR, and EELS (see Powell et al., 2014)
Intended use	Dietary source of iron	n.a.
Material composition	Hydrated matter: iron 28.0 (25.2–31.2) w/w %, tartaric acid 28.2 (26.7–31.0) w/w %, adipic acid 1.8 (1.7–2.1) w/w %, sodium 9.0 (8.7–9.7) w/w %, w/w %, chloride 3.1 (2.3–3.7) w/w %, and adsorbed water 15.9 (11.2–20.7) w/w %. The remainder (14%) is assumed to be structural hydrogen and oxygen, as per the accepted structure for 2‐line ferrihydrite (5Fe2O3 8H2O; Chappell et al., 2017). As dry matter: iron 33.2 (30.4–35.1) w/w %, tartaric acid 32.7 (28.9–35.0) w/w %, adipic acid 2.1 (1.9‐2.5) w/w %, sodium 10.7 (10.5–11.0) w/w %, chloride 3.6 (2.6–4.1) w/w %.	Iron: ICP‐OES, UV.VIS Adipic and tartaric acids: HPLC‐DAD Sodium, chloride: ICP‐OES Water: Karl Fischer titration
Elemental composition	Primary nanoparticles have been shown to contain iron, oxygen, and carbon.	EDX
CAS number	2460638‐28‐0	n.a.
Molecular weight	Average molecular weight: 35,803.4 Da (lower limit: 27,670.5 Da; upper limit: 45,319.4 Da). These results were obtained by modelling. The model was based on: Spherical form of IHAT particles Structure of ferrihydrite as described in Chappell et al. (2017) [https://doi.org/10.1103/PhysRevMaterials.1.036002] Mean diameter of average IHAT particle: 2.32 nm (calculated as mean of average diameters of 5 independent IHAT batches, ranging from 2.12 nm to 2.61 nm) Composition of IHAT: 28.0% w/w Fe, 28.2% w/w tartaric acid and 1.8% adipic acid.	Modelled
Molecular formula	FeOm(OH)n(H2O)x(C4H6O6)y(C 6 H 10 O 4 )z where: m and n are undefined as per accepted practice for ferric iron oxohydroxides (see Cornell and Schwertmann, 2003) x = 0.28–0.88 y = 0.78–1.50 z = 0.04–0.19 Tartaric acid (C4H6O6) and adipic acid (C6H10O4) are represented in their protonated form.	Calculated
Constituent particle size	Minimum external dimension by electron microscopy: Median diameter = 1.98 nm (uncertainty = 0.02 nm, 95% confidence level), width of distribution: mean absolute value (MAD) = 0.99 nm; Mean diameter = 2.31 nm (uncertainty = 0.02 nm, 95% confidence level), width of distribution: standard deviation (SD) = 1.39 nm.	Electron microscopy (HAADF‐STEM)
Particle shape	Constituent particles of almost spherical shape. TEM micrographs at magnifications: (a) 250,000x (b) 400,000x.	TEM
Structure	Schematic molecular structure of IHAT (red: oxygen; white: hydrogen; black: carbon; brown: iron)	n.a.
Specific surface area	Given that the median radius of IHAT particles is 1.55 nm (volume mean diameter 3.1 nm) and the density is 2.15 g/cm3, a value of 904 m2/g is obtained.	Calculated
Appearance	Red‐brown microsized powder.	n.a.
Density	2.14 g/cm3	Pycnometry
Surface charge	Zeta potential at pH 6.4: – 47.6 mV.	Electrophoretic light scattering
Solubility [g/L]	2–4% in water (proportion of solute in solvent at room temperature, with regard to iron content).	n.a.
Agglomeration and/or aggregation state and size	In water, the following phase distribution is observed by ultrafiltration and ICP‐OES analysis: 95.9% nanoparticulates, 2.8% soluble, 1.3% microparticulates. Nanoparticulates show the following size distribution by dynamic light scattering expressed as a function of volume (Dv nm; conversion from intensity of the scattering signal to volume [mean ± SD]): Dv(10): 1.9 ± 0.24 Dv(50): 3.1 ± 0.25 Dv(90): 5.4 ± 0.32 (refractive Index 1.920, Absorption = 0.10). Microparticulates show the following particle size distribution by laser diffraction (volume‐based particle size; µm [mean ± SD]): Dv(10): 26 ± 33.08 Dv(50): 547.7 ± 67.20 Dv(90): 1,286.6 ± 52.73.	Ultrafiltration and ICP‐OES Dynamic light scattering Laser diffraction