Registration Dossier
Registration Dossier
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EC number: 261-235-4 | CAS number: 58398-71-3
Endpoint summary
Administrative data
Description of key information
Additional information
Appearance/physical state/colour: Calcium magnesium (di)hydroxide oxide is a beige powder at room temperature
(reliable data from a GLP guideline compliant study report).
Melting point: > 450 °C (study result, EU A.1 method).
Boiling point: This study does not need to be conducted for solids with a melting point above 300 °C (melting point of this substance: > 450 °C) (cf. section 7.3 Column 2 Annex VII of regulation (EC) 1907/2006).
Relative density: Relative density (compared to water at 4 °C) is D4R= 2.59 (20.5 °C) (study result, EU A.3 method).
Particle size distribution (Granulometry): Total Dustiness (airborne fraction): 87.53 mg/g (experimental results, DMT Report). MMAD = 14.33 µm (GSD: 3.93 µm) (distribution fitted to cascade impactor data). Fractional deposition in human respiratory tract (MPPD model, based on the MMAD): Head (ET): 53.0 % ; Tracheobronchial (TB): 1.2 % ; Pulmonary (PU): 2.7 %
Vapour pressure: Calcium magnesium (di)hydroxide oxide is a solid with a melting point of > 450 °C. The vapour pressure need not be determined experimentally for solids with a melting point above 300 °C (cf. section 7.5 Column 2 Annex VII of Regulation (EC) 1907/2006).
Partition coefficient: This study generally does not need to be conducted for inorganic substances (cf. section 7.8 Column 2 Annex VII of Regulation (EC) 1907/2006).
Water solubility of calcium magnesium (di)hydroxide oxide: 1851.42 mg/l at 20 ± 0.5 °C (study results, modified EU A.6 method, recalculated value from calcium and magnesium)
Surface tension: This study only needs to be conducted if, based on the structure, surface activity is expected or can be predicted, which is not the case for this substance: Calcium magnesium (di)hydroxide oxide is not known to exhibit such a structure (hydrophilic head group and hydrophobic tail) (cf. section 7.6 Column 2 Annex VII of Regulation (EC) 1907/2006).
Flash point: This study is only relevant for liquids or low melting point solids, which is not the case for this substance. Further, this study generally does not need to be conducted for inorganic substances (cf. section 7.9 Column 2 Annex VII of Regulation (EC) 1907/2006).
Auto-flammability: The test material showed no relative self-ignition temperature below 400 °C (study results, EU A.16 method).
Flammability: Non-flammable (study result, EU A.10 method).
Explosiveness: According to the provisions of EU A.14 method, expert judgement considered the test substance to be void of any chemical structures commonly associated with explosive properties.
Oxidising properties: According to the provisions of EU A.17 method, expert judgement considered the test substance as a not oxidising substance.
Stability in organic solvents and identity of relevant degradation products: This study does not need to be conducted for inorganic substances (cf. section 7.15 Column 2 Annex IX of Regulation (EC) 1907/2006).
Dissociation constant: In accordance with section 1, Annex XI of Regulation (EC) 1907/2006 (REACH), this study does not need to be conducted. This property is applicable only for ionisable organic substances. Calcium magnesium (di)hydroxide oxide is an inorganic salt, which reacts with water to give a solution of calcium, magnesium and hydroxide ions. The oxide fraction is converted into hydroxide in contact with water. Therefore, when dissolved in water, the substance is completely ionised into Ca2+, Mg2+ and OH- ions. The concept of dissociable functional groups is therefore not applicable. Therefore, the determination of a dissociation constant is not considered to be required (ECHA Guidance on information requirements and chemical safety assessment Chapter R.7a: Endpoint specific guidance, section R.7.1.17).
Viscosity: Viscosity is a property of liquids. Since calcium magnesium (di)hydroxide oxide is a solid at ambient temperature (ca. 20 °C) such a study does not need to be conducted for this substance (melting point: >450 °C) (in accordance with section 1, Annex XI of Regulation (EC) 1907/2006 (REACH)) .
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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