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Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Appearance:
On the basis of physical observation the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was found to be a Red to orange-brownish powder.

Melting point:
The melting point determination of 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was done following OECD Guideline 102 and according to the metal block capillary method. The test was conducted in replicates and Mean Melting Temperature Range was found to be 153.5-156.6°C at 964.8hPa.

Boiling Point:
The boiling point determination of 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was done following OECD Guideline 103 and according to the method of Siwoloboff. and boiling point was found to be greater than 300 °C at 967.4 hPa.

Density:
The density of test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was determined following OECD Guideline 109 and according to the method Adapted from ASTM D854-02 using pyknometer .The mean density of test item was found to be 0.4702 g/cm³ at 20°C and 965.15 hPa.

Particle size distribution:
The particle size distribution of test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6 ) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was found to be in the range of 150 micron to 25 micron.

Vapour pressure:
Vapour pressure of test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was determined to be 0.000001559 Pa at 25°C.

Partition coefficient:
The partition coefficient (log Pow) value of the substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was estimated to be 6.60. On the basis of the estimated value, chemical 1 -[(2,4 -dimethylphenyl) diazenyl]-2 -naphthol can be considered hydrophobic in nature.

Water solubility:
The solubility value of the given test substance 1-(2,4 -dimethylphenylazo)-2 -naphthol in water is found to be 0.05445 mg/l at 25°C indicating it to be insoluble.

Surface tension:
Surface tension of 1-[(2, 4-dimethylphenyl) diazenyl]-2-naphthol is estimated from modelling database (ACD/Labs) Software (v12.1.0.50375 to be 0.0418 N/m.

Flash point:
The mean flash point of 1-(2,4-dimethylphenylazo)-2-naphthol(CAS No. 3118-97-6) was 213.6°C at 963.4 hPa.

Auto flammability:
1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol did not catch fire on being exposed to air at room temperature of 27°Cpressure of 966 hPa. This indicates that 1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol is not auto-flammable.

Flammability:
1-[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol does not indicate any ignition when the flame of bunsen burner having temperature of approximately 950°C is brought in contact with it. Thus it can be concluded that 1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol is not flammable at high temperature. However since such high temperatures are not found under normal circumstances of transportation and use, thus 1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol was considered non-flammable for chemical safety assessment.

Explosiveness:
The study does not need to be conducted because there are no chemical groups present in the molecule which are associated with explosive properties.

Oxidizing properties:
The study does not need to be conducted because the organic substance contains oxygen or halogen atoms which are chemically bonded only to carbon or hydrogen and hence, the classification procedure does not need to be applied.

pH:
The pH determination of test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was done as per the test guideline OECD 122. The mean pH of the test dispersion was determined with the help of digital pH meter. The mean pH was found to be 6.69 at 26.1 °C.

Additional information

Appearance:
On the basis of physical observation the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was found to be a Red to orange-brownish powder.

From other reliable source also it is concluded that 1-[(2, 4-dimethylphenyl)diazenyl]-2-naphthol is Brownish red to red or orange coloured organic solid in powder/needle form.

Melting point:
The melting point determination of Test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6 ) was done as per the test guideline OECD 102. The method followed was according to Capillary/metal block. The Mean Melting Temperature Range was found to be 153.5-156.6°C at 964.8 hPa.

From the other reliable sources melting point of 1-[(2,4 -dimethylphenyl)diazenyl]-2-naphthol was determined to be in the range of 156 to 166°C, which is close to the selected key value.

Boiling Point:
The boiling point determination of 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was done following OECD Guideline 103 and according to the method of Siwoloboff. and boiling point was found to be greater than 300°C at 967.4 hPa.

From the other reliable sources predicted value of 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol EPI Suite and ACD LAB (v12.1.0.50375) is estimated to be 429.59˚C and 476.71˚C respectively, which in turn supports the selected experimental key value of >300°C.

Density:
The density of test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was determined following OECD Guideline 109 and according to the method Adapted from ASTM D854-02 using pyknometer .The mean density of test item was found to be 0.4702 g/cm³ at 20°C and 965.15 hPa.

Other supporting data is based on prediction done using ACD/I-Lab 2.0 and the density is estimated to be 1.14 g/cm3.

As the data from lab has K1 reliability and the test was performed using OECD guidelines which has the value of density as 0.4702 g/cm³at 20 °C and 965.15 hPa, thus considered as key study for the chemical safety assessment.

Particle size distribution:
The particle size distribution of test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6 ) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was found to be in the range of 150 micron to 25 micron.

Vapour pressure:
Vapour pressure of test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was determined to be 0.000001559 Pa at 25°C.
From other reliable sources, vapour pressure of 1 -[(2,4 -dimethylphenyl)diazenyl]-2 -naphthol  at 25 deg C was estimated to be 0.000001347 Pa.

Partition coefficient:
Based on the available data from authoritative databases and handbook, the partition coefficient (log Pow) value of the substance 1 -[(2,4-dimethylphenyl)diazenyl]-2-naphthol was estimated to be 6.60. On the basis of the estimated value, chemical 1 -[(2,4 -dimethylphenyl)diazenyl]-2-naphthol can be considered hydrophobic in nature which is supported by its water solubility value.

Water solubility:
Based on the available data from various sources like Handbook and authoritative databases, the solubility value of the given test substance 1 -[(2,4 -dimethylphenyl)diazenyl]-2-naphthol in water is found to 0.05445 mg/l at 25°C indicating it to be insoluble.

Surface tension:
Surface tension of 1-[(2, 4-dimethylphenyl) diazenyl]-2-naphthol is estimated from modelling database (ACD/Labs) Software (v12.1.0.50375 to be 0.0418 N/m.

Flash point:
The flash point determination of 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was done following closed cup method using Pensky-Martens flash point apparatus. The test was conducted in replicates and mean flash point was found to be 213.6°C at 963.4hPa.

Other supporting data indicates the flash point of 1-[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol from calculated model to be 238.79 Deg C, which is close to selected key value.

Auto flammability:
1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol did not catch fire on being exposed to air at room temperature of 27°Cpressure of 966 hPa. This indicates that 1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol is not auto-flammable.

Flammability:
1-[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol does not indicate any ignition when the flame of bunsen burner having temperature of approximately 950°C is brought in contact with it. Thus it can be concluded that 1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol is not flammable at high temperature. However since such high temperatures are not found under normal circumstances of transportation and use, thus 1 -[(2, 4 -dimethylphenyl) diazenyl]-2 -naphthol was considered non-flammable for chemical safety assessment.

Explosiveness:
The study does not need to be conducted because there are no chemical groups present in the molecule which are associated with explosive properties.

Oxidizing properties:
The study does not need to be conducted because the organic substance contains oxygen or halogen atoms which are chemically bonded only to carbon or hydrogen and hence, the classification procedure does not need to be applied.

pH:
The pH determination of test item 1-(2,4-dimethylphenylazo)-2-naphthol (CAS No. 3118-97-6) was done as per the test guideline OECD 122. The mean pH of the test dispersion was determined with the help of digital pH meter. The mean pH was found to be 6.69 at 26.1 °C.