Reaction mass of Sodium, bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulphonato(3-)]chromate(1-) and sodium [3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1Hpyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulphonato(3-)]hydroxychromate(1-)]

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

March 17, 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

1. SOFTWARE: EPISUITE 4.1
2. MODEL : MPBPVP 1.43
3. SMILES USED AS INPUT FOR THE MODEL: [O-][N+](=O)c2cc1N=Nc3c(O[Cr](O)Oc1c(c2)S(=O)(=O)O[Na])n(nc3C)c4ccccc4

Principles of method if other than guideline:

QSAR method
Smile notation:
MPBPWIN estimates vapor pressure (VP) by three separate methods: (1) the Antoine method, (2) the modified Grain method, and (3) the Mackay method.  All three use the normal boiling point to estimate VP.  Unless the user enters a boiling point on the data entry screen,  MPBPWIN uses the estimated boiling point from the adapted Stein and Brown method.
The modified Grain method used by MPBPWIN is a modification and significant improvement of the modified Watson method.  It is applicable to solids, liquids and gases.
Estimation Accuracy
The accuracy of MPBPWIN's "suggested" VP estimate was tested on a dataset of 3037 compounds with known, experimental VP values between 15 and 30 deg C (the vast majority at 25 or 20 deg C).  The experimental values were taken from the PHYSPROP Database that is part of the EPI Suite.  For this test, the CAS numbers were run through MPBPWIN as a standard batch-mode run (using the default VP estimation temperature of 25 deg C) and the batch estimates were compared to PHYSPROP's experimental VP.
The 3037 compound test set contains 1642 compounds with available experimental Boiling points and Melting points. For this subset of compounds, the estimation accuracy statistics are (based on log VP):
 number = 1642
  r2 = 0.949
  std deviation = 0.59
  avg deviation = 0.32
These statistics clearly indicate that VP estimates are more accurate with experimental BP and MP data.

GLP compliance:

no

Type of method:

other: QSAR estimation

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0 Pa

Remarks on result:

other: Prediction made by Epiwin 4.1 of the US EPA by a Modified Grain method

This result was estimated by QSAR according to the Modified Grain method.

Smile notation used for prediction: [O-][N+](=O)c2cc1N=Nc3c(O[Cr](O)Oc1c(c2)S(=O)(=O)O[Na])n(nc3C)c4ccccc4

Conclusions:

Estimated Vp = 4.6 x 10^-28 Pa.

Executive summary:

Column 2 of the REACH Regulation Annex VII provides the following specific rules for adaptation of the standard information requirement for vapour pressure.

The study does not need to be conducted if the melting point is above 300 °C. If the melting point is between 200 °C and 300 °C, a limit value based on measurement or a recognised calculation method is sufficient.

Based on the OECD Guideline 104, the calculated values of the vapour pressure can be used:

- for deciding which of the experimental methods is appropriate,

- for providing an estimate or limit value in cases where the experimental method cannot be applied due to technical reasons (including where the vapour pressure is very low, e.g., less than 10-3 Pa).

The estimation method proposed by the OECD 104 is the modified Watson correlation, for which the only experimental data required is the normal boiling point.

The DSC analysis showed decomposition of the product from 239 °C, therefore before any boiling occurs.

Therefore, the modified Watson correlation cannot be used. Nevertheless a prediction made by Epiwin 4.1 of the US EPA by a Modified Grain method has been conducted and the vapour resulted: 4.6 × 10^-28, at 25 °C.

The smile notation used for estimation is: [O-][N+](=O)c2cc1N=Nc3c(O[Cr](O)Oc1c(c2)S(=O)(=O)O[Na])n(nc3C)c4ccccc4

The predicted value of vapour pressure is out of the recommended range of the pressures of the methods reported in the OECD Guideline (10^-5 – 10^5 Pa).

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

March 17, 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

1. SOFTWARE: EPISUITE 4.1
2. MODEL : MPBPVP 1.43
3. SMILES USED AS INPUT FOR THE MODEL: [Na]Oc6n(nc(C)c6/N=N/c5cc(cc(c5O[Cr]2Oc1c(cc(cc1S(=O)(=O)O[Na])[N+]([O-])=O)N=Nc3c(O2)n(nc3C)c4ccccc4)S(=O)(=O)O[Na])[N+]([O-])=O)c7ccccc7

Principles of method if other than guideline:

QSAR method
Smile notation: [Na]Oc6n(nc(C)c6/N=N/c5cc(cc(c5O[Cr]2Oc1c(cc(cc1S(=O)(=O)O[Na])[N+]([O-])=O)N=Nc3c(O2)n(nc3C)c4ccccc4)S(=O)(=O)O[Na])[N+]([O-])=O)c7ccccc7
MPBPWIN estimates vapor pressure (VP) by three separate methods: (1) the Antoine method, (2) the modified Grain method, and (3) the Mackay method.  All three use the normal boiling point to estimate VP.  Unless the user enters a boiling point on the data entry screen,  MPBPWIN uses the estimated boiling point from the adapted Stein and Brown method.
The modified Grain method used by MPBPWIN is a modification and significant improvement of the modified Watson method.  It is applicable to solids, liquids and gases.
Estimation Accuracy
The accuracy of MPBPWIN's "suggested" VP estimate was tested on a dataset of 3037 compounds with known, experimental VP values between 15 and 30 deg C (the vast majority at 25 or 20 deg C).  The experimental values were taken from the PHYSPROP Database that is part of the EPI Suite.  For this test, the CAS numbers were run through MPBPWIN as a standard batch-mode run (using the default VP estimation temperature of 25 deg C) and the batch estimates were compared to PHYSPROP's experimental VP.
The 3037 compound test set contains 1642 compounds with available experimental Boiling points and Melting points. For this subset of compounds, the estimation accuracy statistics are (based on log VP):
 number = 1642
  r2 = 0.949
  std deviation = 0.59
  avg deviation = 0.32
These statistics clearly indicate that VP estimates are more accurate with experimental BP and MP data.

GLP compliance:

no

Type of method:

other: QSAR estimation

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0 Pa

Remarks on result:

other: Prediction made by Epiwin 4.1 of the US EPA by a Modified Grain method

This result was estimated by QSAR according to the Modified Grain method.

Smile notation used for prediction: [Na]Oc6n(nc(C)c6/N=N/c5cc(cc(c5O[Cr]2Oc1c(cc(cc1S(=O)(=O)O[Na])[N+]([O-])=O)N=Nc3c(O2)n(nc3C)c4ccccc4)S(=O)(=O)O[Na])[N+]([O-])=O)c7ccccc7

Conclusions:

Estimated Vp = 2.14E-035 Pa.

Executive summary:

Column 2 of the REACH Regulation Annex VII provides the following specific rules for adaptation of the standard information requirement for vapour pressure.

The study does not need to be conducted if the melting point is above 300 °C. If the melting point is between 200 °C and 300 °C, a limit value based on measurement or a recognised calculation method is sufficient.

Based on the OECD Guideline 104, the calculated values of the vapour pressure can be used:

- for deciding which of the experimental methods is appropriate,

- for providing an estimate or limit value in cases where the experimental method cannot be applied due to technical reasons (including where the vapour pressure is very low, e.g., less than 10-3 Pa).

The estimation method proposed by the OECD 104 is the modified Watson correlation, for which the only experimental data required is the normal boiling point.

The DSC analysis showed decomposition of the product from 239 °C, therefore before any boiling occurs.

Therefore, the modified Watson correlation cannot be used. Nevertheless a prediction made by Epiwin 4.1 of the US EPA by a Modified Grain method has been conducted and the vapour resulted: 2.14E-035, at 25 °C.

The smile notation used for estimation is: [Na]Oc6n(nc(C)c6/N=N/c5cc(cc(c5O[Cr]2Oc1c(cc(cc1S(=O)(=O)O[Na])[N+]([O-])=O)N=Nc3c(O2)n(nc3C)c4ccccc4)S(=O)(=O)O[Na])[N+]([O-])=O)c7ccccc7

The predicted value of vapour pressure is out of the recommended range of the pressures of the methods reported in the OECD Guideline (10^-5 – 10^5 Pa).

Description of key information

Calculation

Component 1: 4.6E-028 Pa, at 25 °C.

Component 2: 2.14E-035  Pa, at 25 °C.

Additional information

Column 2 of the REACH Regulation Annex VII provides the following specific rules for adaptation of the standard information requirement for vapour pressure.

The study does not need to be conducted if the melting point is above 300 °C. If the melting point is between 200 °C and 300 °C, a limit value based on measurement or a recognised calculation method is sufficient.’

Based on the OECD Guideline 104, the calculated values of the vapour pressure can be used:

- for deciding which of the experimental methods is appropriate,

- for providing an estimate or limit value in cases where the experimental method cannot be applied due to technical reasons (including where the vapour pressure is very low, e.g., less than 10-3 Pa).

The estimation method proposed by the OECD 104 is the modified Watson correlation, for which the only experimental data required is the normal boiling point.

The DSC analysis showed decomposition of the product from 239 °C, before any melting or boiling occurs.

Therefore, the modified Watson correlation cannot be used. Nevertheless a prediction made by Epiwin 4.1 of the US EPA by a Modified Grain method has been conducted for both components of the substance and the vapours resulted to be:

- 4.6E-028 Pa, at 25 °C for component 1;

- 2.14E-035  Pa, at 25 °C for component 2.

The smile notations used for estimation are:

- [O-][N+](=O)c2cc1N=Nc3c(O[Cr](O)Oc1c(c2)S(=O)(=O)O[Na])n(nc3C)c4ccccc4 for component 1;

- [Na]Oc6n(nc(C)c6/N=N/c5cc(cc(c5O[Cr]2Oc1c(cc(cc1S(=O)(=O)O[Na])[N+]([O-])=O)N=Nc3c(O2)n(nc3C)c4ccccc4)S(=O)(=O)O[Na])[N+]([O-])=O)c7ccccc7 for component 2.

The predicted values of vapour pressure are out of the recommended range of the pressures of the methods reported in the OECD Guideline (10^-5 – 10^5 Pa).