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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

Appearance/physical state/colour :

On the basis of physical observation and using the sense of smell, 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs was found to be a red coloured organic liquid with no odour at 30°C and 975 hPa.

Melting point:

Melting point study could not be conducted since 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs is in liquid form. Supporting study indicate the melting point of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs to be 349.84 deg.C

Boiling point :

The boiling point of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs by the distillation method was found to be 246.8°C at the atmospheric pressure of 975 hPa. No decomposition of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs was observed at the boiling point. The other authoritative source of information though indicate the boiling point to be 543.75°C. However for the purpose of the dossier as well as for the chemical safety report, the boiling point of the key study which is 246.8°C shall be considered. This boiling point value at 101325 Pa is equivalent to 256.48°C.

Density :

The experimental value of density of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. by the mass by volume method was found to be 0.955 g/cm3 at room temperature of 30°C .This value when converted into 20°C is equivalent to 0.636 g/cm3.

Particle size distribution (Granulometry) :

Granulometry (particle size distribution is a property that is relevant only to solids. Since 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs.is a liquid substance this testing is not scientifically possible and hence this end point was considered for waiver.

Vapour pressure:

According to EPI Suite, vapour pressure of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs is estimated to be 0.00000000061 Pa by Modified Grain Method.

Partition coefficient :

The experimental value of octanol water partition co-efficient (log Pow) of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. is (-1) at 30°C and pH of 5.27. This value indicates that 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. is relatively hydrophobic in nature. The other authoritative source of information indicates the partition co-efficient (log Pow) to be 8.7196. However for the purpose of the dossier as well as for the chemical safety report, the octanol water partition co-efficient (log Pow) value of the key study which is(-1) shall be considered.

Water solubility :

The experimental value of the water solubility of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. was found to be 10000 mg/L at 30°C indicating that it is soluble in water.The supporting studies show values different from the key study which could be due to the difference in the estimation conditions. However for the purpose of the dossier and chemical safety assessment, the key study values shall be used.

Solubility in organic solvents / fat solubility :

Gravimetric method was used to determine the solubility of the substance in organic solvent. The experimental value of solubility of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. in ethanol at 30°C was found to be 60000 mg/L indicating that this substance is soluble in ethanol. This value at 20 degC is equivalent to 40000 mg/L.

The experimental value of solubility of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. in Petroleum ether at 30°C was found to be 30000 mg/L indicating that this substance is soluble in petroleum ether.

Flash point :

The flash point of a substance is the lowest temperature at which it can form an ignitable mixture in air. The experimental value of flash point of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. by the closed cup method was found to be 43.6°C at 975 hPa.This value when converted into 101 325 pascal is equivalent to 45.31°C.

Auto flammability :

2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. did not catch fire on being exposed to air at room temperature of 30°C and atmospheric pressure of 975 hPa. This indicates that 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. is not auto-flammable.

Flammability :

From the experimental values of flammability, it is found that 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. ignited when the flame of bunsen burner having temperature of 950°C was brought in contact with it. Thus it can be concluded that 2-Naphthalenol, 1-[[4-(phenylazo) phenyl]azo]-, ar',ar''-Me derivs. is flammable only at high temperature of about 950°C. However since such high temperatures are not found under normal circumstances of transportation and use, 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. was considered non-flammable for chemical safety assessment.

Explosiveness

According to theoretical considerations based on chemical structure, 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs does not possess explosive properties. The reason for this is there are no chemical groups associated with explosive properties in 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs.Thus, as per column 2 of Annex VII this end point was considered for waiver.

Oxidising properties :

2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. was found to have weak oxidising property since 40.5 mg/ml of KMnO4 was required for getting the end point of the redox titration for 100 g of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs.

Stability in organic solvents and identity of relevant degradation products :

2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. was found to be unstable in organic solvent dichloro methane and degradation products were formed after 24 hours as evident from the GC-MS chromatogram obtained at 0 hours and that obtained after 24 hours.

pH :

1% solution of 2-Naphthalenol,1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs.was found to exhibit a pH of 7.17 at 24°C. Thus 1% by volume solution of 2-Naphthalenol,1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs.is neutral in nature

Dissociation constant :

The experimental pKa value for 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. was found to be 0.000000000001744, 0.00000000000175, and 0.00000000000174 at 30°C indicating that the substance has dissociation properties.The average pKa value at 20°C is equivalent to 0.0000000000011631

Viscosity :

Dynamic viscosity of 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs. was found to be 5.2907 mPa·s at 30°C. This value at 20°C is equivalent to 3.5271 mPa·s.