4-nitroaniline

Endpoint summary

Additional information

Appearance/physical state/colour :

On the basis of physical observation and using the sense of smell, 4-nitroaniline was found to be a brown organic powdered solid with characteristic odour at at 30°C and 970 hPa.

Melting point/freezing point :

The melting point of 4-nitroaniline by the capillary method was found to be 158 degC at an atmospheric pressure of 975 hPa.There was no decomposition & sublimation observed of 4-nitroaniline at the melting point.The other authoritative supporting sources of information also indicate the melting point of 4-nitroaniline to be in the range 146 degC to 152 degC. However, for the purpose of the dossier as well as for the chemical safety report the experimental value of melting point will be considered.Melting point value at 101325 Pa works out to be 164.19 degC.

Boiling point :

The boiling point of 4-nitroaniline by the distillation method was found to be >800 degC at the atmospheric pressure of 975 hPa.No decomposition of 4-nitroaniline was observed at the boiling point.The other authoritative source of information though indicate the boiling point to be 332 degC.However for the purpose of the dossier as well as for the chemical safety report, the boiling point of the key study which is>800degC shall be considered.Boiling point value at 101325 Pa works out to be 831.384 degC.

Density :

The bulk density of 4-nitroaniline by the mass by volume method was found to be 0.951 g/cm3 at room temperature of 30 °C .This value when converted into 20 degC is equivalent to 0.634 g/cm3. 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.

Particle size distribution (Granulometry) :

The particle size distribution (granulometry) of 4-nitroaniline by the sieve analysis method was found to be in the range of 75 micrometer to 500 micrometer. Majority of the particles were found to be in the size more than 500 (39.79%) - 250 (26.19%) micrometer in size.

Vapour pressure :

Applying the weight of evidence approach, the vapour pressure of 4-nitroaniline was found to be in the range 0.02 - 0.6 Pascal (Pa) at 20 degC.

Partition coefficient :

The experimental value of octanol water partition co-efficient (log Pow) of 4-nitroaniline is 1.2 at 30 degC and pH of 4.71.This value indicates that 4-nitroaniline is relatively hydrophilic in nature.

Water solubility :

The experimental value of the water solubility of 4-nitroaniline was found to be 1000 mg/L at 30 degC 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 4-nitroaniline in ethanol at 30 degC was found to be 1500 mg/L indicating that this substance is soluble in ethanol. This value at 20 degC is equivalent to 1000 mg/L.

Surface tension :

In accordance with Column 2 adaptation statement of REACH Annex VII, information requirement 7.6, this end point was considered for waiver since surface activity was not considered a desired property of 4-nitroaniline.

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 4-nitroaniline by the closed cup method was found to be 100.8 degC at 975 hPa.This value when converted into 101 325 pascal is equivalent to 104.75 degC.

Auto flammability :

4-nitroaniline did not catch fire on being exposed to air at room temperature of 30 degC and atmospheric pressure of 975 hPa. This indicates that 4-nitroaniline is not auto-flammable.

Flammability :

From the experimental values of flammability, 4-nitroaniline ignited when the flame of bunsen burner having temperature of 950 degC was brought in contact with it. Thus it can be concluded that 4-nitroaniline 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, 4-nitroaniline was considered non-flammable for chemical safety assessment.

Explosiveness :

According to theoretical considerations based on chemical structure, 4-nitroaniline does not possess explosive properties. The reason for this is there are no chemical groups associated with explosive properties in 4-nitroaniline. Thus, as per column 2 of Annex VII this end point was considered for waiver.

Oxidising properties :

4-nitroaniline was found to have mild oxidising property since 374.5 ml of KMnO4 was required for getting the end point of the redox titration for 100 g of 4-nitroaniline.

Stability in organic solvents and identity of relevant degradation products :

4-nitroaniline was found 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 4-nitroaniline was found to exhibit a pH of 7.45 at 24 degC. Thus 1% by volume solution of 4-nitroaniline is neutral in nature.

Dissociation constant :

The experimental pKa value for 4-nitroaniline was found to be 0.000000000000174,0.000000000000172,0.000000000000175 at 30 degC indicating that it has dissociation properties.The average pKa value at 20 Deg C is equivalent to 0.000000000000115777778.

Viscosity :

This end point was considered for waiver since viscosity is an inherent property of a liquid that offers resistance to its flow and 4-nitroaniline is a solid substance and hence this testing was considered scientifically unjustified for 4-nitroaniline.