Copper oxide

Endpoint summary

Additional information

The physical and chemical properties are summarised in the following table:

Property	Value	Remarks
Physical state at 20°C and 101.3 kPa	Solid	Form: Powder Colour: Dark grey Odour: Odourless
Melting/freezing point	1326 °C
Boiling point	Not applicable	Boiling point will occur at temperatures greater than 360 °C, based on melting point.
Relative density	6.31 g/cm3
Vapour pressure	Not applicable	It is not possible to determine a vapour pressure due to the high melting point (and hence high boiling point) of copper oxide.
Surface tension	Not applicable	A determination of surface tension is not applicable, as copper oxide has very low water solubility at environmental pH.
Water solubility	Solubility at pH 6: 0.000394 g/l Solubility at pH 5.1 - 5.5: > 0.23 g/l Solubility at pH 9: 0.00001 g/l	The solubility of copper oxide in water at 20°C was tested at a range of pH. Solubility characteristics were dependent on acid availability. Therefore, increased solubility could be achieved by increasing the acidic pH of the sample solution. Samples tested at 30.0°C +/- 0.5°C and 10.0°C +/- 0.5°C showed no temperature dependent changes on solubility.
Partition coefficient n-octanol/water (log value)	0.00000085	The octanol:water partition coefficient, Pow, is defined as the ratio of the equilibrium concentrations of a dissolved substance in each of the phases in a two phase system consisting of octanol and water. It is usually expressed on a log scale. It is a key parameter in studies of the environmental fate of organic substances, indicating the potential for bioaccumulation and soil absorption. However, the mechanisms of absorption of Cu2+ into organic matter and living cells are understood to be different from those traditionally attributed to carbon-based substances and the parameter therefore has little relevance to ionic copper. The parameter is therefore not considered to be relevant to copper oxide.
Flash point	Not applicable	A Flash-point was not determined, as this is not relevant to solid compounds, such as copper oxide.
Flammability	Not applicable	Based on chemical composition, a determination of flammability was not carried out, as this test could be predicted to give a negative result.
Explosive properties	Not applicable	Based on the chemical composition and experience in use, it is considered that this test would give a negative result for copper oxide.
Self-ignition temperature	Not applicable	Based on chemical composition, a determination of flammability was not carried out, as this test could be predicted to give a negative result.
Oxidising properties	No oxidising properties.
Granulometry	Volume-rated particle size distribution ranges by laser diffraction: D(v,0.1) 2.68 - 24.03 µm; D(v,0.5) 18.73 - 89.6 µm; D(v,0.9) 46.83 - 899.3 µm. Number-rated particle size distribution ranges by laser diffraction: D(n,0.1) 0.157 – 0.684 µm; D(n,0.5) 0.220 – 0.943 µm; D(n,0.9) 0.457 – 2.23 µm.	Joint registrants that produce or import copper oxide corresponding to this specificatin are able to refer to the Lead Registrants granulometry data for the purpose of REACH registration.   The material does not fall under the category of nanomaterial (50% < 0.1 µm based on particle number). The Exposure Scenarios developed under REACH are based on the worst-case assumption that 100% of any material becoming airbourne is respirable.
Stability in organic solvents and identity of relevant degradation products	Not applicable	As stated in the REACH regulations, the study does not need to be conducted if the substance is inorganic.
Dissociation constant	Not applicable	Based on chemical composition, it is not possible to determine a dissociation constant for copper oxide in water.
Viscosity	Not applicable	A determination of viscosity is not applicable to a solid, such as copper oxide.
Auto flammability	Not applicable	Based on chemical composition, a determination of flammability was not carried out, as this test could be predicted to give a negative result.