Registration Dossier
Registration Dossier
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EC number: 215-168-2 | CAS number: 1309-37-1
Endpoint summary
Administrative data
Description of key information
Diiron trioxide is an inorganic, red crystalline solid. It exists in two forms: powder and nanomaterial.
Diiron trioxide has a very low water solubility ~1-2µg/L after 25 days at pH6-7.
Melting point: 1565°C
Relative density: 5.25
Additional information
Information on nanoform-specific physico-chemical properties of diiron trioxide:
- Specific area: A maximum surface area of 151 m²/g is reported.
- Zeta Potential: The zeta potential is not a characteristic of the metal oxide or the particle consisting of iron oxide in itself.
- Porosity: The average width of the micropores as determined by electron microscopy was twice that found by t-plot analysis of the N2 adsorption/desorption isotherms, because the electron beam causes broadening of the pores.
- Surface Chemistry: The surface chemistry of iron oxide and ferrite pigments is determined by the oxygen present on the surface and their hydroxylation. So no feasible surface activity is observed beside the typical adsorption of species.
- Agglomeration/Aggregation: Like most particulate substances diiron oxide is present in a highly agglomerated and aggregated form only. These are to be separated in the dispersion process.
- Crystalline Phase: Fe2O3 is used to the vast majority in their α-modification. A small part of γ-Fe2O3 is also used. While distinguishable by X-ray-diffraction the α- and γ-modification are very similar in physical and chemical characteristics. No difference is to be expected in toxicological and eco-toxicological aspects.
- Photocatalytic Activity: No known photocatytic activities of iron oxide and ferrite pigments.
- Pour Density: Result given as tamped density: 0.7 - 1.1 g/ml
- Aspect Ratio: Median aspect ratio 1.3 +/- 0.3
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