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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Appearance:

In an experiment conducted by SSS(Europe)AB,the chemical 1-phenylazo-2-naphthol was orange to orange red colored powder in appearance.

Melting point:

The melting point determination of 1-phenylazo-2-naphthol (CAS No. 842-07-9) 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 determined to be 157.1°C -162.3°C at 976.8hPa.

Boiling point:

The boiling point determination of 1-phenylazo-2-naphthol (CAS No. 842-07-9) was done following OECD Guideline 103 and according to the method of Siwoloboff. The test was conducted and The chemical melts at 157.1-162.3 °C.String of bubbles were not observed but the test item rises in capillary above 265°C,inferring boiling point to be greater than 265°C at 978.2 hPa at 978.2 hPa.

Density:

The density of chemical 1-phenylazo-2-naphthol (CAS No. 842-07-9)was determined following OECD Guideline 109 and according to the method Adapted from ASTM D854-02using glass pyknometer. The mean density of test item is was found to be 0.3194g/cm³ at 20°C and 977.8 hPa.

Particle Size Distribution:

The particle size distribution of test test item 1-phenylazo-2-naphthol (CAS No 842-07-9 ) was determined by granulometric analysis with rotap sieve shaker. Theparticle sizedistribution was determined to be in the range of 150 micron to 25 micron.

Vapour Pressure:

Data from handbooks and authoritative databases suggests that the estimated vapor pressure of1-phenylazo-2-naphtholat 25 deg C was 0.0000000734 mmHg (9.785e-06 Pa).

Partition Coefficient:

Data from handbooks and various modeling, authoritative databases suggests that the estimated LogPow of 1-phenylazo-2-naphthol was 5.51. This value indicates that 1-phenylazo-2-naphthol is hydrophobic in nature, which is also supported by its low solubility in water.

Water Solubility:

The water solubility determination of test item 1-phenylazo-2-naphthol (CAS No. 842-07-9) was done as per the OECD guideline 105 by spectrophotometric analytical method as per OECD 101. The solubility of (1-phenylazo-2-naphthol of 842-07 -9 )in water was found to be 0.01845 mg/L at 30°C.Thus, it can be concluded that 1-phenylazo-2-naphthol is insoluble in water.

Solubility in organic solvents:

A study was conducted to determine the solubility of 1-phenylazo-2-naphthol in various organic solvents. 1-phenylazo-2-naphthol was determined to be soluble in ethanol, carbon disulphide, benzene, pet. 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. The1-phenylazo-2-naphthol(842-07-9)  is used as a coloring agent. For this use, surface activity is not an important property. Hence this study was considered for waiver.

Flash point:

The flash point determination of 1-phenylazo-2-naphthol (CAS No. 842-07-9)was done following closed cup method using Pensky-Martens flash point apparatus. The test was conducted in replicates and .the test item burns completely at 290°Cwith brown fumes and pungent smell.But no flash was observed till 290°C,inferring the mean flash point of the test item to be greater than 290°C at 977.3 hPa.

Autoflammability:

The study does not need to be conducted as the melting point of 1-phenylazo-2-naphthol was determined to be 134 degree C which is less than equal to 160 degree C. Hence the auto ignition temperature endpoint was considered for waiver.

Flammability:

The substance 1-phenylazo-2-naphtholis a solid and has a NFPA rating of 1. It is not flammable under normal conditions of use. Hence this endpoint can be considered for waiver.

Explosiveness:

There are no chemical groups associated with explosive properties present in the chemical except azo group. Since, the azo group does not contribute to the explosiveness property. Thus, the chemical is considered to be "Non explosive".

Oxidising Properties:

The study does not need to be conducted because there are no chemical groups present in1-phenylazo-2-naphtholwhich are associated with oxidising properties. Hence, this endpoint was considered for waiver.

pH:

The pH determination of test item 1-phenylazo-2-naphthol (CAS No 842-07-9) was done following OECD guideline 122. pH of 1% w/v dispersion was measured with the help of pH meter and it was observed to be 10.20 at 26 °C.Based on the study the 1-phenylazo-2-naphthol (CAS No 842-07-9) was considered to be basic in nature.

Viscocity:

The study does not need to be conducted because the chemical1-phenylazo-2-naphtholis solid.

Additional information

Appearance:

In an experiment conducted by SSS(Europe)AB,the chemical 1-phenylazo-2-naphthol was orange to orange red colored powder in appearance.

Other supporting studies from various reliable sources such as authoritative database,handbook and review articles,the chemical 1-phenylazo- 2-naphthol w as darkish red to yellow colored crystals in appearance.

Melting point:

The melting point determination of 1-phenylazo-2-naphthol (CAS No. 842-07-9) 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 determined to be 157.1°C -162.3°C at 976.8hPa.

Other supporting studies from various reliable sources such as authoritative database and handbooks suggests that the melting point of chemical was reported to be in the range of 131 degree C to 134 degree C.

As the data from lab has K1 reliability and the test was performed using OECD guidelines which has the value of melting point temperature as 157.1 degree C to 162.3 degree C, thus considered as key study for the chemical safety assessment.

Boiling point:

The boiling point determination of 1-phenylazo-2-naphthol (CAS No. 842-07-9) was done following OECD Guideline 103 and according to the method of Siwoloboff. The test was conducted and the chemical melts at 157.1-162.3 °C. String of bubbles were not observed but the test item rises in capillary above 265°C, inferring boiling point to be greater than 265°C at 978.2 hPa at 978.2 hPa.

Density:

The density of chemical 1-phenylazo-2-naphthol (CAS No. 842-07-9)was determined following OECD Guideline 109 and according to the method Adapted from ASTM D854-02using glass pyknometer. The mean density of test item is was found to be 0.3194g/cm³ at 20°C and 977.8 hPa.

Other supporting study from various authoritative databases suggests that the density of chemical 1-phenylazo-2-naphtholwas reported to be 0.18 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 0.3149 g/cm3 thus considered as key study for the chemical safety assessment.

Particle Size Distribution:

The particle size distribution of test test item 1-phenylazo-2-naphthol (CAS No 842-07-9 ) was determined by granulometric analysis with rotap sieve shaker. Theparticle sizedistribution was determined to be in the range of 150 micron to 25micron.

Vapour Pressure:

Data from handbooks and authoritative databases suggests that the estimated vapor pressure of 1-phenylazo-2-naphthol at 25 deg C was 0.0000000734 mmHg (9.785e-06 Pa).

Partition Coefficient:

Data from handbooks and various modeling, authoritative databases suggests that the estimated LogPow of 1-phenylazo-2-naphthol was 5.51. This value indicates that 1-phenylazo-2-naphthol is hydrophobic in nature, which is also supported by its low solubility in water.

Water Solubility:

The water solubility determination of test item 1-phenylazo-2-naphthol (CAS No. 842-07-9) was done as per the OECD guideline 105 by spectrophotometric analytical method as per OECD 101. The solubility of (1-phenylazo-2-naphthol of 842-07 -9 )in water was found to be 0.01845 mg/L at 30°C.Thus, it can be concluded that 1-phenylazo-2-naphthol is insoluble in water.

Based on the data from various handbooks and modelling databases suggests that the estimated water solubility of 1-phenylazo-2-naphthol at 25 deg C was 0.6738 mg/l. This indicates that 1-phenylazo-2-naphthol is insoluble to very slightly soluble in water.

As the data from lab has K1 reliability and the test was performed using OECD guidelines which has the value of water solubility as 0.01845 at 30 degC, indicating the substance to be insoluble in water, thus considered as key study for the chemical safety assessment.

Solubility in organic solvents:

A study was conducted to determine the solubility of 1-phenylazo-2-naphthol in various organic solvents. 1-phenylazo-2-naphthol was determined to be soluble in ethanol, carbon disulphide, benzene, pet. ether. It was also determined to be soluble in acetone.

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. The1-phenylazo-2-naphthol(842-07-9)  is used as a coloring agent. For this use, surface activity is not an important property. Hence this study was considered for waiver.

Flash point:

The flash point determination of 1-phenylazo-2-naphthol (CAS No. 842-07-9)was done following closed cup method using Pensky-Martens flash point apparatus. The test was conducted in replicates and .the test item burns completely at 290°Cwith brown fumes and pungent smell.But no flash was observed till 290°C,inferring the mean flash point of the test item to be greater than 290°C at 977.3 hPa.

As per the available data for flash point from laboratory, the flash point value determined was >290 degree C. As the data from laboratory has K1 reliability thus considered as key study for the chemical safety assessment. Also based on criteria mentioned in CLP regulation the chemical has flash point >than 60 degree C hence the substance 1-phenylazo-2-naphthol (CAS No. 842-07-9) was considered to be non-flammable.

Autoflammability:

The study does not need to be conducted as the melting point of 1-phenylazo-2-naphthol was determined to be 134 degree C which is less than equal to 160 degree C. Hence the auto ignition temperature endpoint was considered for waiver.

Flammability:

The substance 1-phenylazo-2-naphtholis a solid and has a NFPA rating of 1. It is not flammable under normal conditions of use. Hence this endpoint can be considered for waiver.

Explosiveness:

There are no chemical groups associated with explosive properties present in the chemical except azo group. Since, the azo group does not contribute to the explosiveness property. Thus, the chemical is considered to be "Non explosive".

Oxidising Properties:

The study does not need to be conducted because there are no chemical groups present in1-phenylazo-2-naphtholwhich are associated with oxidising properties. Hence, this endpoint was considered for waiver.

pH:

As per the available data for pH from laboratory, the pH value of 1-phenylazo-2-naphthol (CAS No 842-07-9) was determined to be 10.20 at 26 degree C. As it has K1 reliability was considered as key study.

The pH determination of test item 1-phenylazo-2-naphthol (CAS No 842-07-9) was done following OECD guideline 122. pH of 1% w/v dispersion was measured with the help of pH meter and it was observed to be 10.20 at 26 °C.Based on the study the 1-phenylazo-2-naphthol (CAS No 842-07-9) was considered to be basic in nature.

Viscocity:

The study does not need to be conducted because the chemical1-phenylazo-2-naphtholis solid.