Copper dihydroxide

Endpoint summary

Additional information

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

Property	Value	Remarks
Physical state at 20˚C and 101.3 kPa	Solid.	Form: Powder. Colour: Munsell 5B 7/8 (Blue). Odour: Weak, ammonia-like.
Melting/freezing point	Decomposition before melting point.	Decomposition at an onset temperature of 229 °C.
Boiling point	Not applicable.	No boiling point before decomposition.
Relative density	3.717 ± 0.19 at 20˚C.
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 dihydroxide.
Surface tension	Not applicable.	Test not conducted because the water solubility is less than 1 mg/L.
Water solubility	pH 8.1: 6.80x10^-4g/L (4.43x10^-4g/L as Cu). pH 4: 39.8 g/L (> 25.9 g/L as Cu). pH 6.5: 5.06x10^-4g/L (3.29x10^-4g/L as Cu). pH 10: <2.50x10^-4g/L (<1.63x10^-4g/L as Cu).	Determined at 30.1 °C. Determined at 20.0 ± 0.5 °C.
Partition coefficient n-octanol/water (log value)	Not applicable.	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 Cu^2+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 dihydroxide.
Flash point	Not applicable.	Not required as the substance is solid.
Flammability	Not flammable.	The copper form is inorganic ionic salt or mineral in solid form. Wholly inorganic salts are not combustible or flammable.
Explosive properties	Not explosive.
Self-ignition temperature	Not applicable.	Copper dihydroxide was assessed for the presence of chemical groups that imply explosive properties. Since none of these are present in the chemical structure of the test substance, copper dihydroxide is considered not to be explosive.
Oxidising properties	No oxidising properties.	The oxygen is bound up in very stable structural groupings with strong oxygen bonds. The decomposition temperature is also indicating a high energy of activation. Copper hydroxide is considered inert under the conditions of oxidation.
Granulometry	Volume-rated particle size distribution by laser diffraction: D(v,0.1) 1.40 µm; D (v,0.5) 5.52 µm; D(v,0.9) 13.4 µm. Number-rated particle size distribution by laser diffraction: D(n,0.1) 0.200 µm; D (n,0.5) 0.409 µm; D(n,0.9) 1.05 µm.	Joint registrants that produce or import copper dihydroxide corresponding to this specification are able to refer to the Lead Registrant's 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.	Copper is a poorly soluble metallic element that can only remain in solution in a totally dissociated ionic state; a non-reversible process. Since its solubility is low and it does not exist in solution in an associated state, it does not therefore have a measureable dissociation constant.
Viscosity	Not applicable.	Not applicable to solids.
Auto flammability	Not applicable.	The copper form is inorganic ionic salt or mineral with copper in a high oxidation state. As such this material is not likely to undergo self-heating under bulk storage conditions and is unlikely to combust. It is therefore not likely to auto-ignite.