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Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Appearance:

On the basis of physical observation ,the chemical 3-methylsulphanilic acid was observed to be nearly white coloured powder in appearance.

Other supporting study from reliable study report also suggests that the chemical 3-methylsulphanilic acid was observed to be white coloured crystalline powder in appearance.

Melting point:

The melting point determination of 3-methylsulphanilic acid (CAS No. 98-33-9) was done following OECD Guideline 102 and according to the metal block capillary method. The test was conducted in replicates and Mean decomposition temperature was  determined to be 306.7°C -318.2°C at 978.5hPa.

Boiling point:

The study does not need to be conducted because the substance is a solid which decomposes before boiling.

Density:

The density of test item 3-methylsulphanilic acid (CAS No. 98-33-9)was determined following OECD Guideline 109 and according to the Test methods: Pour density and tapped density of powders” recommended in The International Pharmacopoeia, Fourth Edition, 2014 using bulk density apparatus.The mean pour density and tapped density of test item  was determined to be 0.4085 g/cm³ and 0.5885 g/cm³ at 29.1°C and 978.5 hPa.

Particle Size Distribution:

The particle size distribution of test item 3-methylsulphanilic acid (CAS No. 98-33-9 ) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was determined to be in the range of 150 micron to 75micron.

Vapour Pressure:

The study does not need to be conducted since the melting point is above 300 deg C. The Mean decomposition temperature of 3-methylsulphanilic acid was determined be 306.7°C -318.2°C at 978.5hPa.Hence this endpoint was considered for waiver.

Partition Coefficient:

The partition Coefficient n-octanol/water of 3-methylsulphanilic acid(CAS No.98-33-9) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 117 for testing of Chemicals.The reference substances were chosen according to functional group similarity with the test substance and calibration graph was prepared. The reference substances were benzene, biphenyl, 2,6-Diphenylpyridine, Triphenylamine, 4-Acetylpyridine,Toluene, Ethylbenzene, n-Butylbenzene and Naphthalene having Pow value ranging from 0.5 to 5.7. The Log Pow value was determined to be 0.0760 ± 0.0385 at 25°C.

KOWWIN v1.68 was used to estimate the octanol water partition coefficient of 4-amino-3-methylbenzenesulfonic acid. The estimated logPow of 4-amino-3-methylbenzenesulfonic acid was -1.53. The experimental and estimated values indicate that 4-amino-3-methylbenzenesulfonic acid can be considered to be hydrophillic in nature which also supported by its high solubility in water.

Water Solubility:

The water solubility determination of test item 3-methylsulphanilic acid (CAS No. 98-33-9) was done as per the OECD guideline 105 and by spectrophotometric analytical method as per OECD 101. The solubility of 3-methylsulphanilic acid (CAS: 98-33-9) in water was determined to be 6121.46 mg/L at 30°C.

WSKOW v1.42 was used to estimate the water solubility of 4-amino-3-methylbenzenesulfonic acid.

Water solubility of 3 -methylsulphanilic acid was estimated to be 10380 mg/l at 25 deg C.

The experimental and estimated values suggest that 4-amino-3-methylbenzenesulfonic acid is highly soluble in water.

Surface tension:

Based on the data from ACD labs, surface tension for3-methylsulphanilic acidwas predicted to be61.7±3.0 dyne/cm.

Flash point

The flash point determination of 3-methylsulphanilic acid (CAS No. 98-33-9)was done following closed cup method using Pensky-Martens flash point apparatus. The test was conducted in replicates and mean flash point was determined to be 175°C at 977.0hPa. Based on criteria mentioned in CLP regulation the substance methyl

3-methylsulphanilic acid (CAS No. 98-33-9)was considered to be non flammable.

Autoflammability:

3-methylsulphanilic acid did not catch fire on being exposed to air at room temperature of 27°C and atmospheric pressure of 966 hPa. This indicates that 3-methylsulphanilic acid is not auto-flammable.

Flammability:

3-methylsulphanilic acid 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 3-methylsulphanilic acid is not flammable at high temperature. However since such high temperatures are not found under normal circumstances of transportation and use, thus 3-methylsulphanilic acid was considered non-flammable for chemical safety assessment.

Explosivenss:

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

Oxidising properties:

In accordance with column 2 of Annex VII of the REACH regulation, the substance 3-methylsulphanilic acid is incapable of reacting exothermically with combustible materials on the basis of the chemical structure. It is an organic substance containing oxygen but no halogen atom and these elements are not chemically bonded to nitrogen or oxygen. Thus, the chemcial is likely to be "Non-oxidising".

pH:

The pH determination of test item 3-methylsulphanilic acid (CAS No 98-33-9) was done following OECD guideline 122. pH of 1% w/v solution was measured with the help of pH meter and it was observed to be 2.25at 29 °C. Thus, 1% solution can be considered to be acidic in pH.

Viscosity:

The study does not need to be conducted because the substance is a solid

Additional information

Appearance:

On the basis of physical observation ,the chemical 3-methylsulphanilic acid was observed to be nearly white coloured powder in appearance.

Other supporting study from reliable study report also suggests that the chemical 3-methylsulphanilic acid was observed to be white coloured crystalline powder in appearance.

Melting point:

The melting point determination of 3-methylsulphanilic acid (CAS No. 98-33-9) was done following OECD Guideline 102 and according to the metal block capillary method. The test was conducted in replicates and Mean decomposition temperature was  determined to be 306.7°C -318.2°C at 978.5hPa.

Boiling point:

The study does not need to be conducted because the substance is a solid which decomposes before boiling.

Density:

The density of test item 3-methylsulphanilic acid (CAS No. 98-33-9)was determined following OECD Guideline 109 and according to the Test methods: Pour density and tapped density of powders” recommended in The International Pharmacopoeia, Fourth Edition, 2014 using bulk density apparatus.The mean pour density and tapped density of test item  was determined to be 0.4085 g/cm³ and 0.5885 g/cm³ at 29.1°C and 978.5 hPa.

Other supporting study from reliable handbook source indicates that the density of substance 3-methylsulphanilic acid was determined  to be 1.3553 g/cm³ at 25 deg.C

As the data from lab has K1 reliability and the test was performed using OECD guidelines which has the value of densityas 0.4085g/cm3 (pour density),0.5885 g/cm3 (tapped density),,thus considered as key study for the chemical safety assessment.

Particle Size Distribution:

The particle size distribution of test item 3-methylsulphanilic acid (CAS No. 98-33-9 ) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was determined to be in the range of 150 micron to75micron.

Vapour Pressure:

The study does not need to be conducted since the melting point is above 300 deg C. The Mean decomposition temperature of 3-methylsulphanilic acid was determined be 306.7°C -318.2°C at 978.5hPa.Hence this endpoint was considered for waiver.

Partition Coefficient:

The partition Coefficient n-octanol/water of 3-methylsulphanilic acid(CAS No.98-33-9) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 117 for testing of Chemicals.The reference substances were chosen according to functional group similarity with the test substance and calibration graph was prepared. The reference substances were benzene, biphenyl, 2,6-Diphenylpyridine, Triphenylamine, 4-Acetylpyridine,Toluene, Ethylbenzene, n-Butylbenzene and Naphthalene having Pow value ranging from 0.5 to 5.7. The Log Pow value was determined to be 0.0760 ± 0.0385 at 25°C.

KOWWIN v1.68 was used to estimate the octanol water partition coefficient of 4-amino-3-methylbenzenesulfonic acid. The estimated logPow of 4-amino-3-methylbenzenesulfonic acid was -1.53. The experimental and estimated values indicate that 4-amino-3-methylbenzenesulfonic acid can be considered to be hydrophillic in nature which also supported by its high solubility in water.

Water Solubility:

The water solubility determination of test item 3-methylsulphanilic acid (CAS No. 98-33-9) was done as per the OECD guideline 105 and by spectrophotometric analytical method as per OECD 101. The solubility of 3-methylsulphanilic acid (CAS: 98-33-9) in water was determined to be 6121.46 mg/L at 30°C.

WSKOW v1.42 was used to estimate the water solubility of 4-amino-3-methylbenzenesulfonic acid.

Water solubility of 3-methylsulphanilic acid was estimated to be 10380 mg/l at 25 deg C.

The experimental and estimated values suggest that 4-amino-3-methylbenzenesulfonic acid is highly soluble in water.

Surface tension:

Based on the data from ACD labs, surface tension for3-methylsulphanilic acidwas predicted to be61.7±3.0 dyne/cm.

Flash point

The flash point determination of 3-methylsulphanilic acid (CAS No. 98-33-9)was done following closed cup method using Pensky-Martens flash point apparatus. The test was conducted in replicates and mean flash point was determined to be 175°C at 977.0hPa. Based on criteria mentioned in CLP regulation the substance methyl 3-methylsulphanilic acid (CAS No. 98-33-9)was considered to be non flammable.

Autoflammability:

3-methylsulphanilic acid did not catch fire on being exposed to air at room temperature of 27°C and atmospheric pressure of 966 hPa. This indicates that 3-methylsulphanilic acid is not auto-flammable.

Flammability:

3-methylsulphanilic acid 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 3-methylsulphanilic acid is not flammable at high temperature. However since such high temperatures are not found under normal circumstances of transportation and use, thus 3-methylsulphanilic acid was considered non-flammable for chemical safety assessment.

Explosivenss:

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

Oxidising properties:

In accordance with column 2 of Annex VII of the REACH regulation, the substance 3-methylsulphanilic acid is incapable of reacting exothermically with combustible materials on the basis of the chemical structure. It is an organic substance containing oxygen but no halogen atom and these elements are not chemically bonded to nitrogen or oxygen. Thus, the chemcial is likely to be "Non-oxidising".

pH:

The pH determination of test item 3-methylsulphanilic acid (CAS No 98-33-9) was done following OECD guideline 122. pH of 1% w/v solution was measured with the help of pH meter and it was observed to be 2.25at 29 °C. Thus, 1% solution can be considered to be acidic in pH.

Viscosity:

The study does not need to be conducted because the substance is a solid