6-amino-4-hydroxynaphthalene-2-sulphonic acid

Endpoint summary

Description of key information

Appearance:

On the basis of physical observation and using the sense of smell test chemical was observed to be an odorless amorphous, grey color substance.

Melting point:

Melting point of test chemical is determine to be 190 Deg C.

Boiling Point:

Boiling point of test substance is determine to be 458 degree C.

Density:

The density of test chemical by the mass by volume method was determine to be 0.580 g/cm3 at room temperature of 33 °C .

Particle size distribution:

The particle size distribution (granulometry) of test chemical by the sieve analysis method was determine to be in the range of 75 micrometer to 500 micrometer. Majority of the particles were determine to be in the size more than 250 (39.25%) - 150 (26.54%) micrometer in size.

Vapour pressure:

The estimated vapour pressure of the test substance at 25deg C was 3.26E-11 hPa.

Partition coefficient

Based on the available data from authoritative and modelling databases,the partition coefficient (log Pow) value of the test chemical was estimated to be -1.39. On the basis of this value, test chemical can be considered to be hydrophilic in nature.

Water solubility:

The experimental value of the water solubility of test chemical was determine to be 180 mg/L at temperature of 33 deg C indicating that test chemical is moderately soluble in water.

Solubility in organic solvents / fat solubility:

The experimental value of solubility of test chemical in methanol at temperature of 33 deg C was determine to be 1060 mg/L indicating that test chemical is slightly soluble in methanol.

The experimental value of solubility of test chemical in Petroleum ether at temperature of 33 deg C was determine to be 70mg/L indicating that test chemical is slightly soluble in Petroleum ether.

Surface tension:

In accordance with column 2 of Annex VII of the REACH regulation, the study need only be conducted if surface activity is a desired property of the chemical. Test chemical is used as a dye intermediate. For this use, surface activity is not an important property. Hence this study was considered for waiver.

Flash point:

Test Substance was determine to be Non Flammable and flash point was not determined (upto 350 deg c).

Auto flammability:

Test chemical did not catch fire on being exposed to air at room temperature of 33 deg C and atmospheric pressure of 990 hPa. This indicates that test chemical is not auto-flammable.

Flammability:

From the experimental values of flammability, 6-amino-4-hydroxynaphthalene-2-sulphonic acid ignited when the flame of bunsen burner having temperature of 950 degC was brought in contact with it. Thus it can be concluded that 6-amino-4-hydroxynaphthalene-2-sulphonic acid is flammable only at high temperature of about 950 degC. However since such high temperatures are not found under normal circumstances of transportation and use, 6-amino-4-hydroxynaphthalene-2-sulphonic acid was considered non-flammable.

Explosiveness:

According to theoretical considerations based on chemical structure, test chemical does not possess explosive properties. The reason for this is there are no chemical groups associated with explosive properties in test chemical. Thus, as per column 2 of Annex VII this end point was considered for waiver.

Oxidizing properties:

Test chemical was determine to be oxidising since 280.47 ml of KMnO4 was required for getting the end point of the redox titration for 100 g of test chemical.

Stability in organic solvents and identity of relevant degradation products:

Test chemical was observed to be stable in organic solvent dichloro methane and no 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% by volume solution of test chemical was determine to exhibit a pH of 3.03 at 25 deg C. Thus 1% by volume solution of test chemical is relatively acidic in nature.

Dissociation constant:

The experimental pKa value for test chemical was determine to be 0.0000212233 (average pKa value) at 33 deg C indicating that the chemical has dissociation properties.

Viscosity:

This end point was considered for waiver since viscosity is an internal property of a liquid that offers resistance to flow and test chemical is a solid substance and hence this testing was considered scientifically unjustified for test chemical.

Additional information

Appearance:

On the basis of physical observation and using the sense of smell test chemical was observed to be an odorless amorphous, grey color substance.

From other sources test chemical physically appear as a solid grey powder.

Melting point:

Melting point of test chemical is determine to be 190 Deg C.

From authoritative databases melting point of test chemical is determine to be 200 Deg C.

Boiling Point:

Boiling point of test substance is determine to be 458 degree C.

Density:

The density of test chemical by the mass by volume method was determine to be 0.580 g/cm3 at room temperature of 33 °C.

From other databases density of test chemical is determine to be ca. 0.6 g/cm3.

Particle size distribution:

The particle size distribution (granulometry) of test chemical by the sieve analysis method was determine to be in the range of 75 micrometer to 500 micrometer. Majority of the particles were determine to be in the size more than 250 (39.25%) - 150 (26.54%) micrometer in size.

Vapour pressure:

Modified Grain method was used to estimate the vapour pressure of the test substance using MPBPVP v1.43 of EPI SUITE.

The estimated vapour pressure of the test substance at 25deg C was 3.26E-11 hPa.

Partition coefficient

Based on the available data in a key study from authoritative and modelling databases, the partition coefficient (log Pow) value of the test chemical was estimated to be -1.39.

In a supportingstudy from handbook, the partition coefficient (log Pow) value of the test chemical was estimated to be -0.4.

Additional study from modelling database indicates that the octanol water partition coefficient (log Pow) value of the test chemical was estimated to be -1.46 ± 1.07.

Thus, based on the available information, the logPow valueof the test chemical ranges from -1.46 to -0.4, respectively. On the basis of this value, test chemical can be considered to behydrophilic in nature.

Water solubility:

The experimental value of the water solubility of test chemical was determine to be 180 mg/L at temperature of 33 deg C indicating that test chemical is moderately soluble in water.

Solubility in organic solvents / fat solubility:

The experimental value of solubility of test chemical in methanol at temperature of 33 deg C was determine to be 1060 mg/L indicating that test chemical is slightly soluble in methanol.

The experimental value of solubility of test chemical in Petroleum ether at temperature of 33 deg C was determine to be 70mg/L indicating that test chemical is slightly soluble in Petroleum ether.

Surface tension:

In accordance with column 2 of Annex VII of the REACH regulation, the study need only be conducted if surface activity is a desired property of the chemical. Test chemical is used as a dye intermediate. For this use, surface activity is not an important property. Hence this study was considered for waiver.

Flash point:

Test Substance was determine to be Non Flammable and flash point was not determined (up to 350 deg c).

Auto flammability:

Test chemical did not catch fire on being exposed to air at room temperature of 33 deg C and atmospheric pressure of 990 hPa. This indicates that test chemical is not auto-flammable.

Flammability:

From the experimental values of flammability, 6-amino-4-hydroxynaphthalene-2-sulphonic acid ignited when the flame of bunsen burner having temperature of 950 degC was brought in contact with it. Thus it can be concluded that 6-amino-4-hydroxynaphthalene-2-sulphonic acid is flammable only at high temperature of about 950 degC. However since such high temperatures are not found under normal circumstances of transportation and use, 6-amino-4-hydroxynaphthalene-2-sulphonic acid was considered non-flammable.

Explosiveness:

According to theoretical considerations based on chemical structure, test chemical does not possess explosive properties. The reason for this is there are no chemical groups associated with explosive properties in test chemical. Thus, as per column 2 of Annex VII this end point was considered for waiver.

Oxidizing properties:

Test chemical was determine to be oxidising since 280.47 ml of KMnO4 was required for getting the end point of the redox titration for 100 g of test chemical.

Stability in organic solvents and identity of relevant degradation products:

Test chemical was observed to be stable in organic solvent dichloro methane and no 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% by volume solution of test chemical was determine to exhibit a pH of 3.03 at 25 deg C. Thus 1% by volume solution of test chemical is relatively acidic in nature.

Dissociation constant:

The experimental pKa value for test chemical was determine to be 0.0000212233 (average pKa value) at 33 deg C indicating that the chemical has dissociation properties.

Viscosity:

This end point was considered for waiver since viscosity is an internal property of a liquid that offers resistance to flow and test chemical is a solid substance and hence this testing was considered scientifically unjustified for test chemical.