Copper cyanide

Endpoint summary

Description of key information

See below

Additional information

Appearance/physical state/colour

The substance is a white powder, green crystal solids.

Melting point

The melting point of copper cyanide was determined to be 474°C, based on information from handbooks.

Boiling point

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 7.3 a boiling point study does not need to be conducted as the melting point of the test substance is above 300°C.

Density

According to handbook-data, the density of copper cyanide is 2.9 g/cm3.

Particle size distribution (Granulometry)

The particle size of copper cyanide was measured using the Laser diffraction / scattering method according to KS A ISO 13320 : 2014, by a micro particle size analyzer using laser diffraction and scattering. Irradiated by particles, the intensity of the scattering of light and scattering of light is sensed by the detector, which reaches the particles of light, and thus calculates the size of the particles.

The average particle size of the Copper cyanide sample was 60.3 um after five times of particle size analysis by laser diffraction and scattering.

Vapour pressure

In accordance with column 2 of Reach Regulation 1907/2006/EC Annex VII section 7.5, the vapour pressure does not need to be conducted if the melting point is above 300 degree C. The melting point of copper cyanide was determined to be 474°C. Therefore, a study on vapour pressure is not applicable.

Partition coefficient

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 7.8, the test on partition coefficient n-octanol/water does not need to be conducted if the substance is inorganic. Copper cyanide is an inorganic substance, therefore this endpoint was waived.

For information, the theoretical, calculated (EPIWIN) log Pow is - 1.49, i.e. very low, as expected for an inorganic substance.

Water solubility

According to handbook-data, copper cyanide is considered as insoluble in water.

Surface tension

According to the column 2 of the annex VII section 7.6 of Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), the study does not need to be conducted if the water solubility is below 1 mg/L at 20°C. This is the case of copper cyanide which is insoluble in water. Therefore, the study is scientifically not necessary.

Flash point

According to the column 2 of the annex VII section 7.9 of Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), the study does not need to be conducted if the substance is inorganic. This is the case of copper cyanide which is an inorganic substance. In addition, the flash point is only relevant to liquids and low melting point solids. Copper cyanide is a solid with a high melting point (474°C). Therefore, flash point is not relevant in the case of copper cyanide.

Explosiveness

According to the column 2 of the annex VII section 7.11 of Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), the study does not need to be conducted if there are no chemical groups associated with explosive properties present in the molecule. According to the structural formula of Copper cyanide, Copper cyanide is a chemical group that does not have explosive properties in the molecule (see the attached justification document). Therefore, the study is scientifically not necessary.

Oxidising properties

According to the column 2 of the annex VII section 7.13 of Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), the study does not need to be conducted if the substance is incapable of reacting exothermically with combustible materials, for example on the basis of the chemical substance (e.g. inorganic substances not containing oxygen or halogen atoms). According to constitutional formula of ‘the melting point of Copper cyanide’, Since Copper cyanide does not contain oxygen, fluorine or chlorine, it does not react with flammable substances and does not react with exothermic substances. Therefore this is subject to exemption.

Dissociation constant

Lithium hydroxide is usually considered to be a strong base, almost completely dissociated in aqueous solution. Based on the available data the pKa of lithium hydroxide anhydrous is between 13.8 and 14.18 at 20°C. This result demonstrates the extreme alkaline character of lithium hydroxide anhydrous in aqueous solutions. For lithium hydroxide monohydrate also full dissociation is very likely, whereas the pH value of a solution of comparable morality is expected to be lower, due to the content of crystal water (less hydroxyl ions).

Viscosity

The study which examines viscosity and is required according to REACH Regulation 1907/2006/EC Annex IX section 7.17 does not need to be conducted as the registered substance copper cyanide is a substance that exists as a solid at room temperature. It is scientifically impossible to measure the viscosity of a solid.